Arq Bras Cardiol abc Arquivos Brasileiros de Cardiologia Arq. Bras. Cardiol. 0066-782X 1678-4170 Sociedade Brasileira de Cardiologia - SBC dqRp7Pj4s9BwDkxYn4dCkjB S0066-782X2016004200207 S0066-782X2016005021101 10.5935/abc.20160111 Original Articles Syntax Score and Major Adverse Cardiac Events in Patients with Suspected Coronary Artery Disease: Results from a Cohort Study in a University-Affiliated Hospital in Southern Brazil Fuchs Felipe C. Ribeiro Jorge P. Fuchs Flávio D. Wainstein Marco V. Bergoli Luis C. Wainstein Rodrigo V. Zen Vanessa Kerkhoff Alessandra C. Moreira Leila B. Fuchs Sandra C. Universidade Federal do Rio Grande do Sul Hospital de Clínicas de Porto Alegre Porto Alegre RS Brazil Hospital de Clínicas de Porto Alegre - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS - Brazil Universidade Federal do Rio Grande do Sul Mailing Address: Felipe Costa Fuchs. Serviço de Cardiologia, Hospital de Clínicas de Porto Alegre. Rua Ramiro, Barcelos, 2350, Santa Cecília. Postal Code 90035-903, Porto Alegre, RS - Brazil. E-mail: fcfuchs@terra.com.br

Author contributions

Conception and design of the research: Fuchs FC, Ribeiro JP, Fuchs FD, Moreira LB, Fuchs SC; Acquisition of data: Fuchs FC, Wainstein MV, Bergoli LC, Wainstein RV, Zen V, Kerkhoff AC; Analysis and interpretation of the data and Critical revision of the manuscript for intellectual content: Fuchs FC, Ribeiro JP, Fuchs FD, Bergoli LC, Wainstein RV, Zen V, Kerkhoff AC, Moreira LB, Fuchs SC;Statistical analysis and Writing of the manuscript: Fuchs FC, Ribeiro JP, Fuchs FD, Fuchs SC; Obtaining financing: Ribeiro JP, Moreira LB, Fuchs SC.

Potential Conflict of Interest

No potential conflict of interest relevant to this article was reported.

 08 08 2016 9 2016 107 3 207 215 05 07 2015 21 03 2016 01 04 2016 This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background:

The importance of coronary anatomy in predicting cardiovascular events is well known. The use of traditional anatomical scores in routine angiography, however, has not been incorporated to clinical practice. SYNTAX score (SXscore) is a scoring system that estimates the anatomical extent of coronary artery disease (CAD). Its ability to predict outcomes based on a baseline diagnostic angiography has not been tested to date.

 Objective:

To evaluate the performance of the SXscore in predicting major adverse cardiac events (MACE) in patients referred for diagnostic angiography.

 Methods:

Prospective cohort of 895 patients with suspected CAD referred for elective diagnostic coronary angiography from 2008 to 2011, at a university-affiliated hospital in Brazil. They had their SXscores calculated and were stratified in three categories: no significant CAD (n = 495), SXscoreLOW-INTERMEDIATE: < 23 (n = 346), and SXscoreHIGH: ≥ 23 (n = 54). Primary outcome was a composite of cardiac death, myocardial infarction, and late revascularization. Secondary endpoints were the components of MACE and death from any cause.

 Results:

On average, patients were followed up for 1.8 ± 1.4 years. The primary outcome occurred in 2.2%, 15.3%, and 20.4% in groups with no significant CAD, SXscoreLOW-INTERMEDIATE, and SXscoreHIGH, respectively (p < 0.001). All-cause death was significantly higher in the SXscoreHIGH compared with the 'no significant CAD' group, 16.7% and 3.8% (p < 0.001), respectively. After adjustment for confounding factors, all outcomes remained associated with the SXscore.

 Conclusions:

SXscore independently predicts MACE in patients submitted to diagnostic coronary angiography. Its routine use in this setting could identify patients with worse prognosis.

 Keywords: Coronary Artery Disease / epidemiology Probability Cineangiography Syntax Score Cohort Studies Introduction

The importance of coronary anatomy in predicting cardiovascular events has been known for decades, when studies like CASS (Coronary Artery Study) registry were published.1 This large cohort study showed the ability of anatomical scores of coronary artery disease (CAD) to predict events, but their routine use was not incorporated to clinical practice.2 Nowadays, standard of care indicates functional, noninvasive, assessment of ischemia, such as stress-echocardiogram, nuclear imaging and magnetic resonance imaging, to evaluate patients with known or suspected CAD.3 Nonetheless, a significant number of patients are eventually submitted to coronary angiography for diagnostic confirmation.3 Therefore, re-assessing the performance of anatomical scores to predict outcomes, in a context of newer clinical and interventional therapies, is potentially worthwhile. Currently, the SYNTAX (Synergy between percutaneous coronary intervention with Taxus and Cardiac Surgery) Score (SXscore), a more elaborate method to quantify anatomic lesions, is an available online tool that estimates the anatomical extent of CAD.4

The SXscore is a comprehensive angiographic scoring system based on coronary anatomy and lesion characteristics.4 It was initially developed to determine the extent of CAD and lesion complexity, which reflect the difficulties in performing myocardial revascularization, particularly percutaneous coronary interventions (PCI). In the SYNTAX trial, high SXscore values (above 33) identified patients in whom coronary artery bypass grafting (CABG) resulted in better outcomes than in patients submitted to percutaneous revascularization.5 Five-year follow-up of this trial identified patients with scores above 22 as more suitable for CABG.6

The SXscore was developed as a tool in the decision-making process and, later on, its usefulness was expanded as a predicting score of major adverse cardiac events (MACE) in patients submitted to PCI.7-14 Those studies included elective and urgent revascularization procedures. However, the majority of coronary angiographies are done for diagnostic purposes.15 The prognostic performance of the SXscore in that setting has not been reported to date, and is the aim of this investigation.

 Objective

To evaluate the performance of the SXscore in predicting MACE in patients referred for diagnostic angiography.

 Methods Study design and population

This cohort study enrolled patients with suspected CAD referred for elective, diagnostic coronary angiography, from 2008 to 2011, at a reference tertiary university-affiliated hospital (Hospital de Clínicas de Porto Alegre), in Southern Brazil. The patients were referred by cardiologists from the public health system and private practices, and underwent cardiac catheterization due to suspected CAD with or without previous noninvasive testing for ischemia. Patients referred for angiography due to suspected CAD and associated valvular heart disease were also included. Men and women aged 40 years or over were eligible for the study, excluding those with previous coronary revascularization (surgical or percutaneous), class III or IV heart failure, chronic renal disease (previous medical diagnosis or serum creatinine greater than 1.5 mg/dL), history of cancer, or severe psychiatric illness. Patients admitted to the hospital for acute coronary syndromes were not included.

 Enrollment and study procedures

The study protocol was approved by the hospital's Ethics Committee, which is accredited by the Office for Human Research Protections as an Institutional Review Board, and informed, written consent was obtained. Interviews pertaining demographic information, lifestyle characteristics, and past medical history were done using a standardized questionnaire. After the angiographies, the patients' attending physicians were responsible for assessing the need for revascularization and all medical treatment. The follow-up was conducted from 2008 to 2012.

 SYNTAX score and angiographic analysis

SXscores were calculated prospectively by scoring all coronary lesions producing a ≥ 50% diameter stenosis in vessels ≥ 1.5 mm, using the algorithm that is available at the SYNTAX score website.16 Subsequently, they were categorized as: SXscoreHIGH (≥ 23); SXscoreLOW-INTERMEDIATE (< 23); and no significant CAD (reference category). Two interventional cardiologists (FCF, LCCB) independently performed the angiographic visual analysis for the assessment of the score. They were trained in calculating the SXscore using the website tutorial. Afterwards, they scored another 80 cases, which were extensively discussed with senior interventional cardiologists. Inter- and intra-observer agreement for determination of the SXscore was evaluated in another group of 90 angiographies.

 Study endpoints

The primary endpoint was MACE, defined as a time to first event among cardiac death, myocardial infarction (MI) or late revascularization. Myocardial infarction and revascularization followed by death in the same hospitalization were adjudicated as cardiac deaths. Cardiac death was defined, additionally, as sudden death. Myocardial infarction was diagnosed by an increase or decrease of biomarkers, in the presence of symptoms, ECG abnormalities suggestive of ischemia.17 Some patients were treated for acute MI in other hospitals and the diagnosis was defined on the basis of the discharge diagnosis. Late revascularization was either PCI or CABG.

Percutaneous and surgical revascularizations based on diagnostic angiography findings, performed until three months after the angiography, were defined as index procedures and not considered outcomes. Interventions performed during follow-up, non-directly related to the diagnostic angiography, were defined as late revascularizations and included in the primary outcome. Secondary endpoints were cardiac death, cardiovascular death (fatal MI or stroke), MI, coronary revascularization, and overall mortality.

All deaths were confirmed through verbal autopsy,18 death certificate (obtained at the Government's Health Department, which has all state death records), or hospital records. Myocardial infarction was established by hospitalization, with diagnosis informed by a physician. An independent Clinical Events Committee adjudicated all endpoints. Data collection regarding the outcomes underwent control of quality to verify reliability, and another investigator checked 5% of the verbal autopsies.

 Sample size calculation and statistical analysis

The questionnaires were coded and entered into a database using Epinfo 2004 software (version 3.3.2, Centers for Disease Control and Prevention, Atlanta, USA), with data entry quality control to verify amplitude and consistency. A sample size of 588 participants would be necessary to identify a hazard ratio (HR) of at least 2.4, with 80% power and 5% significance level (two-tailed), considering that 5% of unexposed and 12% of exposed to the highest score, a 1:1.5 ratio, respectively, would present a primary endpoint. Considering the lack of previous reports about the performance of SXscore to predict events in this context, sample size was increased to 906 participants to include enough patients with high scores (>23) to provide adequate statistical power. Epi Info 2004, Statcalc module, was used for sample size calculation.

Inter and intra-observer reliability was assessed by crosschecking 90 angiograms evaluated by two interventional cardiologists and reviewed by a third one. Agreement using Kappa coefficient was done, and interpreted according to Feiss et al.19 Substantial agreement was defined by a Kappa coefficient of 0.7, considering the proportion of patients with SXscore > 23, being 30% according to observer 1 and 20% by observer 2, with accuracy of 0.2. Intraclass correlation coefficients were also calculated.

Recommendations of the STARD20 were used to plan and report this study. Data are presented by mean ±SD, percentages and HR with 95% confidence intervals (CI). Receiver operating characteristic (ROC) curve was used to calculate C-statistic and the area under the curve. Kaplan-Meier survival curve for MACE was calculated for patients according to SXscores. Multivariate analysis of the predictive power of the SXscore was performed using Cox regression, which allowed the estimation of HR and 95% CI. Variables associated to the outcome in the bivariate analysis (P ≤ 0.2) were eligible as confounding factors. Considering that many variables are intermediates in the causation of MACE, they were individually evaluated to be included or not in the analysis. The same model was run having the number of diseased vessels (none, one and multivessel) as exposure variable. The analyses were carried out using the Statistical Package for Social Sciences (SPSS(r), version 17, Chicago, IL, USA) software, and a p value <0.05 was regarded as statistically significant.

 Results

Study flowchart is presented in Figure 1. Among 928 eligible patients, 895 patients with SXscore were included in the cohort and were followed up on average for 1.8 ± 1.4 years. After angiography, 314 (35.1%) patients were submitted to PCI or CABG, and 82 (9.2%) to valve replacement (index procedure). New interventions were done during the follow-up (late revascularizations) in 54 patients (35 percutaneous and 19 surgical). Myocardial infarction occurred in 16 patients, cardiac death in 13, cardiovascular death in 22, and all-cause death in 40 patients. MACE was established in 73 patients.

Flowchart of patients. PCI: percutaneous coronary intervention; CABG: coronary artery bypass grafting; MI: myocardial infarction; CAD: coronary artery disease; CV: cardiovascular; MACE: major adverse cardiac events. * Valve replacement patients were excluded from the outcome analysis. <sup>Ŧ</sup> MACE as defined in methods section.

Spearman coefficient between the SXscores calculated by the two interventional cardiologists was 0.902 (p < 0.001), and the interobserver agreement between them was 0.94 (95% CI: 0.91-0.96). Kappa coefficient was 0.83 for the two interventional cardiologists. There were 495 patients with a score of 0 (55.4%) and 400 (44.6%) with positive scores, ranging from 1 to 43, with a mean of 12.6 (95% CI: 11.7-13.4). Patients with coronary lesions ≥ 50% diameter stenosis in vessels ≥1.5 mm were classified as SXscoreLOW-INTERMEDIATE (n = 345) or SXscoreHIGH (n = 54).

Baseline clinical and angiographic characteristics according to patient categories are presented in Table 1. The mean age of patients with SXscoreHIGH was higher than that of patients with SXscoreLOW-INTERMEDIATE. The proportion of men, patients with diabetes mellitus and hypertension was higher among patients with SXscoreHIGH as well. Clinical indications for diagnostic coronary angiography were not remarkably different by the SXscore, but more patients in the SXscoreLOW-INTERMEDIATE had typical CAD symptoms and more patients without significant CAD had other symptoms. As expected, prevalence of multivessel disease and all markers of increased lesion complexity, such as the presence of total occlusions, bifurcations and small vessel disease, were significantly more frequent in the SXscoreHIGH category.

Baseline clinical characteristics
Baseline characteristics No significant CAD n = 495 SXscoreLOW-INTERMEDIATE n = 346 SXscoreHIGH n = 54 p value
Age 59.1 ± 10.4 60.8 ± 9.6 63.6 ± 8.6 0.002
Male 234 (47.3) 226 (65.3) 39 (72.2) < 0.001
Diabetes mellitus 92 (18.6) 85 (24.6) 18 (33.3) 0.01
Current smoking 65 (13.2) 51 (15.0) 3 (5.6) 0.08
Hypertension 344 (69.8) 260 (76.5) 45 (83.3) 0.02
Symptoms of CAD only 128 (25.9) 115 (33.4) 14 (25.9) 0.05
With a positive noninvasive test 209 (42.2) 139 (40.2) 28 (51.9) 0.3
Valve disease with suspected CAD 14 (2.8) 3 (0.9) 1 (1.9) 0.14
Other complaints 46 (9.3) 13 (3.8) 1 (1.9) 0.002
Angiographic analysis*
Right dominance - 309 (89.3) 51 (94.4) 0.3
Nº. lesions per patient - 1.8 ± 1.0 3.9 ± 1.5 < 0.001
Total occlusions - 88 (25.4) 41 (75.9) < 0.001
Bifurcations - 125 (36.1) 44 (81.5) < 0.001
Small vessels /diffuse disease - 68 (19.7) 26 (48.1) < 0.001
Left main - 13 (13.8) 13 (24.1) < 0.001
Left anterior descending - 218 (63.0) 47 (87.0) < 0.001
Left circumflex - 109 (31.5) 36 (66.7) < 0.001
Right coronary artery - 169 (48.8) 43 (79.6) < 0.001
One vessel disease - 196 (56.7) 4 (7.4) < 0.001
Multivessel disease or LM - 150 (43.3) 50 (92.6) < 0.001

Values are given as n (%) or mean ±SD. LM: left main; CAD: coronary artery disease.

Assessment using the SYNTAX score definitions.

 Procedures after index angiography

The proportion of patients submitted to PCI, CABG and valve replacement based on the index diagnostic angiography according to patient category is presented in Table 2. As expected, more patients with higher scores were submitted to CABG. Despite having no significant CAD based on angiographic assessment done for this study, 3.4% of patients were submitted to PCI.

Treatment after the index angiography and cumulative clinical outcomes across patient categories
Type of procedure No significant CAD n = 495 SXscoreLOW-INTERMEDIATE n = 346 SXscoreHIGH n = 54 p value
Interventions: < 0.001
Percutaneous Coronary Intervention 17 (3.4) 208 (60.3) 14 (25.9)
Coronary Artery Bypass Surgery 0 46 (13.3) 29 (53.7)
Isolated valve replacement* 78 (15.8) 4 (1.2) 0
No invasive intervention 400 (80.8) 88 (25.4) 11 (20.4)
All-cause death 16 (3.9) 11 (3.3) 9 (16.7) < 0.001
Cardiac death and MI 4 (1.0) 13 (3.9) 9 (16.7) < 0.001
Cardiovascular death 9 (2.2) 6 (1.8) 7 (13) < 0.001
MACE 9 (2.2) 53 (15.7) 11 (20.4) < 0.001

Values are given as n (%).

patients excluded from outcome analysis. MI: myocardial infarction; MACE: MI, cardiac death, and late revascularization.

 Clinical outcomes

The cumulative incidence of clinical outcomes across patient groups is shown in Table 2. All-cause death was significantly higher in SXscoreHIGH patients as compared with patients without significant CAD, 16.7% and 3.9% (p < 0.001), respectively. Cardiovascular death, non-fatal MI, and late revascularization were more frequent in the SXscoreHIGH as well. After adjustment for confounding factors, all outcomes remained associated with the SXscore (Table 3). Risk ratios for MACE, cardiac death or non-fatal MI and non-fatal MI alone were significantly associated with SXscoreLOW-INTERMEDIATE as well. Patients in the SXscoreHIGH category had a 12.5 (95% CI: 5.1-30.6) higher chance of presenting the primary outcome than those without significant CAD. This finding was similar among men (10.1; 95% CI: 3.9-25.9) and women (11.5; 95% CI: 1.1-117.3). Further adjustment for index revascularization did not change the estimates significantly. After adjustment for confounding factors, the primary outcome was also associated with the SXscore as a continuous variable (HR 1.06; 95% CI: 1.04-1.08). The area under the ROC curve was 0.73 (95% CI: 0.68-0.79) (Figure 2).

Hazard ratios<xref ref-type="table-fn" rid="TFN06">*</xref> for major clinical outcomes according to patient categories
Type of Event No significant CAD† n = 495 SXscoreLOW-INTERMEDIATE n = 346 SXscoreHIGH n = 54 p value
All-cause death 1.0 0.8 (0.4-1.7) 4.3 (1.8-10.1) < 0.001
Cardiovascular death 1.0 0.7 (0.3-2.1) 5.7 (2.0-15.9) < 0.001
Cardiac death 1.0 1.3 (0.3-5.9) 11.8 (2.9-48.5) < 0.001
MACE‡ 1.0 7.2 (3.5-14.7) 12.5 (5.1-30.6) < 0.001
Cardiac death or MI 1.0 3.5 (1.1-10.8) 16.0 (4.9-52.9) < 0.001
MI 1.0 12.6 (1.6-98.3) 33.9 (3.7-308.0) 0.007
Late Revascularization 1.0 9.9 (4.2-23.4) 4.0 (0.8-20.0) < 0.001

MI: myocardial infarction.

Adjusted for age, sex and diabetes.

Reference category,

MACE: MI, cardiac death, and late revascularization.

ROC curve for the SYNTAX score.

MACE-free survival curves for patients according to SXscores are presented in Figure 3, showing that curves diverged immediately after angiography and further during follow-up. Risk ratios for MACE according to the number of diseased vessels, compared to none, were 6.9 (95% CI: 3.4-13.9) for one-vessel disease and 10.2 (5.2-20.1) for multivessel disease. Despite the intrinsic relationship of this classification and the SXscore, 42.0% of the patients with multivessel disease were classified in the SXscoreLOW-INTERMEDIATE category.

Kaplan-Meier Curve for MACE according to patient category. CAD: coronary artery disease.

Discussion

This study demonstrated that, in patients submitted to diagnostic angiography for suspected CAD, the SXscore was able to predict the primary endpoint of cardiac death, non-fatal MI and late revascularization, independently of age, sex, presence of diabetes and index revascularization. There was a 6% increased risk in having a MACE for each additional point in the score. Patients with SXscoreHIGH had a significantly increased risk for all-cause, cardiovascular and cardiac death.

Previous studies have shown the ability of the SXscore to predict MACE in different scenarios. LEADERS,9,10 SIRTAX11 and RESOLUTE8 studies included patients with acute coronary syndromes as well as patients submitted to elective PCI. MI-SYNTAXscore Study,12 STRATEGY and MULTISTRATEGY13 studies were done in patients with acute MI. The ACUITY7 trial included patients with acute coronary syndromes. Finally, Serruys et al. summarized the results of five studies, analyzing data from 6.508 patients, with the same results.14 Differently from our research, all of those studies included only patients submitted to percutaneous revascularization procedures, and none of them focused on patients with suspected or stable CAD. The group of patients without significant CAD, although many had CAD with diameter stenosis lesser than 50%, served as the reference category to compare outcomes with those of patients in the SXscoreLOW-INTERMEDIATE and SXscoreHIGH categories. We understand that our proposal is different from the application originally proposed for the score, in which patients without lesions treatable with surgery or percutaneously are excluded, but it is in line with the objectives of the study.

The comparison of the SXscore performance with the traditional CAD anatomical scores was not explored in our investigation. The presence of positive SXscores (44.6%) was similar to the frequency of patients with significant CAD (47%) detected by quantitative angiographic analysis done in a proportion of the patients of our cohort.21 Traditional angiographic scores have also predicted the incidence of MACE in previous studies,2 but those scores do not take into account difficulties in performing myocardial revascularization. Despite their prognostic ability, they have not been incorporated to clinical practice, where the number of diseased vessels has been used to estimate the anatomical severity of disease. In this cohort, patients with one-vessel and multivessel disease had a risk for MACE approximately similar to the SXscore low-intermediate and high, respectively. Nonetheless, almost half of the patients with multivessel disease were classified in the SXscoreLOW-INTERMEDIATE category.

Based on the results of the SYNTAX trial,5 in which patients with low SYNTAX scores had similar outcomes regardless of the type of revascularization, our findings have a clinical implication - patients who would otherwise be referred to CABG could also be revascularized percutaneously. Considering that visual characterization of multivessel disease leads to referring patients to surgical revascularization, calculation of the SXscore could better stratify patients who would indeed benefit from this procedure (SXscoreHIGH category).

In this study, patients underwent an elective procedure and, as a result, there was a large proportion of patients with no significant CAD, who might also have lesions below 50%. Those patients did not fulfill the criteria for a positive score and served as a comparison group. Therefore, patients were classified into two categories: 1 to 22, and equal to 23 or greater, which correspond to the later defined categories of low-intermediate (0-22) and high (23 or higher).6 The proportion of patients classified as SXscoreLOW-INTERMEDIATE and submitted to percutaneous revascularization was higher than patients submitted to surgical revascularization, which reflects the current clinical practice and complies with the findings of the 5-year follow-up of the randomized clinical SYNTAX trial.6 At the time the study was conducted, drug-eluting stents were not available for use in the Brazilian public health system. In addition, current evidence indicates surgical revascularization for patients with high SXscores.6 Patients with high surgical risk who were not deemed eligible for surgical revascularization by surgeons received percutaneous treatment. There was an unexpected finding of 3.4% of patients without significant CAD who were submitted to PCI. Patients with non-obstructive CAD represent a large proportion of patients undergoing coronary angiography. Subjective evaluation of coronary anatomy associated with the clinical and noninvasive information might have influenced the decision-making process and could explain this finding.

Our study has some limitations and strengths that should be addressed. We restricted our analysis to anatomical criteria, considering neither left ventricular function nor myocardial ischemia and viability. Nonetheless, our patients did not have clinically unstable disease or classes III or IV heart failure, and the anatomical criteria frequently prevail to reach a therapeutic decision. In addition, a recent post-hoc analysis of the COURAGE trial has demonstrated that anatomical criteria and not ischemia burden were able to predict cardiovascular events.22 Although most follow-up procedures have been conducted in our hospital, different types of stents were implanted, which could affect the likelihood of stent thrombosis or reinterventions.23 However, analysis including only MI and cardiac death did not change the estimates. Exclusion of patients submitted to valve replacement did not change the results either. Another limitation is the number of events, which accounted for the large confidence intervals. Despite having investigated almost 1,000 patients, more than 50% did not have significant CAD, which reflects real life practice of a tertiary center performing diagnostic angiographies. Studies with larger sample size and conducted at other centers are necessary to confirm our findings and their external validity. The high inter-observer reproducibility of the examiners is among the strengths of our investigation, similar to some24 but different from other studies.25,26 This performance could be explained by the extensive training in assessing SXscore done by the interventional cardiologists and the fact that both underwent training at the same hospital.

Clinical Implications

In clinical practice, the number of epicardial vessels with more than 50% stenosis is used to assess prognostic information, and angiographic scores are rarely used. Recently, the use of scores has been shown to improve the standardization of clinical decision-making. For instance, the EUROSCORE27 or the STS score28 are routinely used in the decision making process for the indication of CABG.29 For the management of multivessel CAD, current guidelines formally recommend the use of the SXscore as well as the EUROSCORE.30 Our data expand the indications of the SXscore for the prognostic evaluation of patients referred for diagnostic angiography.

 Conclusion

In conclusion, in patients with suspected CAD submitted to elective coronary angiography, SXscore independently predicts MACE. Its routine use in this setting could identify patients with worse prognosis.

(in memorian)

Sources of Funding

This study was partially funded by CNPq and Fundação para o incentivo em Pesquisa do Hospital de Clínicas de Porto Alegre.

Study Association

This article is part of the thesis of master submitted by Felipe C. Fuchs, from Faculdade de Medicina da Universidade Federal do Rio Grande do Sul.

 Acknowledgements

This study was partially supported by the National Council for Scientific and Technological Development (CNPq), Brazil; Research Funding of Hospital de Clínicas de Porto Alegre (FIPE-HCPA), Porto Alegre, Brazil.

 References 1 Emond M, Mock MB, Davis KB, Fisher LD, Holmes DR Jr, Chaitman BR, et al. Long-term survival of medically treated patients in the Coronary Artery Surgery (CASS) Registry. Circulation. 1994;90(6):2645-57. Emond M Mock MB Davis KB Fisher LD Holmes DR Jr Chaitman BR Long-term survival of medically treated patients in the Coronary Artery Surgery (CASS) Registry Circulation 1994 90 6 2645 2657 2 Ringqvist I, Fisher LD, Mock M, Davis KB, Wedel H, Chaitman BR, et al. Prognostic value of angiographic indices of coronary artery disease from the coronary artery surgery study (CASS). J Clin Invest. 1983;71(6):1854-66. Ringqvist I Fisher LD Mock M Davis KB Wedel H Chaitman BR Prognostic value of angiographic indices of coronary artery disease from the coronary artery surgery study (CASS) J Clin Invest 1983 71 6 1854 1866 3 Fihn SD, Blankenship JC, Alexander KP, Bittl JA, Byrne JG, Fletcher BJ, et al. 2014 ACC/AHA/AATS/PCNA/SCAI/STS focused update of the guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, and the American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. Circulation. 2014;130(19):1749-67. Fihn SD Blankenship JC Alexander KP Bittl JA Byrne JG Fletcher BJ 2014 ACC/AHA/AATS/PCNA/SCAI/STS focused update of the guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines, and the American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons Circulation 2014 130 19 1749 1767 4 Sianos G, Morel MA, Kappetein AP, Morice MC, Colombo A, Dawkins K. The SYNTAX score: an angiographic tool grading the complexity of coronary artery disease. EuroIntervention. 2005;1(2):219-27. Sianos G Morel MA Kappetein AP Morice MC Colombo A Dawkins K The SYNTAX score: an angiographic tool grading the complexity of coronary artery disease EuroIntervention 2005 1 2 219 227 5 Serruys PW, Morice MC, Kappetein AP, Colombo A, Holmes DR, Mack MJ, et al; SYNTAX Investigators. Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease. N Engl J Med. 2009;360(10):961-72. Erratum in: N Engl J Med. 2013;368(6):584. Serruys PW Morice MC Kappetein AP Colombo A Holmes DR Mack MJ SYNTAX Investigators Percutaneous coronary intervention versus coronary-artery bypass grafting for severe coronary artery disease nullErratum in N Engl J Med. 2013;368(6):584. N Engl J Med 2009 360 10 961 972 6 Mohr FW, Morice MC, Kappetein AP, Feldman TE, Ståhle E, Colombo A, et al. Coronary artery bypass graft surgery versus percutaneous coronary intervention in patients with three-vessel disease and left main coronary disease: 5-year follow-up of the randomised, clinical SYNTAX trial. Lancet. 2013;381(9867):629-38. Mohr FW Morice MC Kappetein AP Feldman TE Ståhle E Colombo A Coronary artery bypass graft surgery versus percutaneous coronary intervention in patients with three-vessel disease and left main coronary disease: 5-year follow-up of the randomised, clinical SYNTAX trial Lancet 2013 381 9867 629 638 7 Palmerini T, Genereux P, Caixeta A, Cristea E, Lansky A, Mehran R, et al. Prognostic value of the SYNTAX score in patients with acute coronary syndromes undergoing percutaneous coronary intervention: analysis from the ACUITY (Acute Catheterization and Urgent Intervention Triage StrategY) trial. J Am Coll Cardiol. 2011;57(24):2389-97. Palmerini T Genereux P Caixeta A Cristea E Lansky A Mehran R Prognostic value of the SYNTAX score in patients with acute coronary syndromes undergoing percutaneous coronary intervention: analysis from the ACUITY (Acute Catheterization and Urgent Intervention Triage StrategY) trial J Am Coll Cardiol 2011 57 24 2389 2397 8 Garg S, Serruys PW, Silber S, Wykrzykowska J, van Geuns RJ, Richardt G, et al. The prognostic utility of the SYNTAX score on 1-year outcomes after revascularization with zotarolimus- and everolimus-eluting stents: a substudy of the RESOLUTE All Comers Trial. JACC Cardiovasc Interv. 2011;4(4):432-41. Garg S Serruys PW Silber S Wykrzykowska J van Geuns RJ Richardt G The prognostic utility of the SYNTAX score on 1-year outcomes after revascularization with zotarolimus- and everolimus-eluting stents: a substudy of the RESOLUTE All Comers Trial JACC Cardiovasc Interv 2011 4 4 432 441 9 Wykrzykowska JJ, Garg S, Girasis C, de Vries T, Morel MA, van Es GA, et al. Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial. J Am Coll Cardiol. 2010;56(4):272-7. Wykrzykowska JJ Garg S Girasis C de Vries T Morel MA van Es GA Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial J Am Coll Cardiol 2010 56 4 272 277 10 Wykrzykowska JJ, Garg S, Onuma Y, de Vries T, Morel MA, van Es GA, et al. Implantation of the biodegradable polymer biolimus-eluting stent in patients with high SYNTAX score is associated with decreased cardiac mortality compared to a permanent polymer sirolimus-eluting stent: two year follow-up results from the "all-comers" LEADERS trial. EuroIntervention. 2011;7(5):605-13. Wykrzykowska JJ Garg S Onuma Y de Vries T Morel MA van Es GA Implantation of the biodegradable polymer biolimus-eluting stent in patients with high SYNTAX score is associated with decreased cardiac mortality compared to a permanent polymer sirolimus-eluting stent: two year follow-up results from the "all-comers" LEADERS trial EuroIntervention 2011 7 5 605 613 11 Girasis C, Garg S, Räber L, Sarno G, Morel MA, Garcia-Garcia HM, et al. SYNTAX score and Clinical SYNTAX score as predictors of very long-term clinical outcomes in patients undergoing percutaneous coronary interventions: a substudy of SIRolimus-eluting stent compared with pacliTAXel-eluting stent for coronay revascularization (SIRTAX) trial. Eur Heart J. 2011;32(24):3115-27. Girasis C Garg S Räber L Sarno G Morel MA Garcia-Garcia HM SYNTAX score and Clinical SYNTAX score as predictors of very long-term clinical outcomes in patients undergoing percutaneous coronary interventions: a substudy of SIRolimus-eluting stent compared with pacliTAXel-eluting stent for coronay revascularization (SIRTAX) trial Eur Heart J 2011 32 24 3115 3127 12 Magro M, Nauta S, Simsek C, Onuma Y, Garg S, van der Heide E, et al. Value of the SYNTAX score in patients treated by primary percutaneous coronary intervention for acute ST-elevation myocardial infarction: the MI SYNTAXscore study. Am Heart J. 2011;161(4):771-81. Magro M Nauta S Simsek C Onuma Y Garg S van der Heide E Value of the SYNTAX score in patients treated by primary percutaneous coronary intervention for acute ST-elevation myocardial infarction: the MI SYNTAXscore study Am Heart J 2011 161 4 771 781 13 Garg S, Sarno G, Serruys PW, Rodriguez AE, Bolognese L, Anselmi M, et al; STRATEGY and MULTISTRATEGY Investigators. Prediction of 1-year clinical outcomes using the SYNTAX score in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a substudy of the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials. JACC Cardiovasc Interv. 2011;4: 66-75. Garg S Sarno G Serruys PW Rodriguez AE Bolognese L Anselmi M STRATEGY and MULTISTRATEGY Investigators Prediction of 1-year clinical outcomes using the SYNTAX score in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a substudy of the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials JACC Cardiovasc Interv 2011 4 66 75 14 Garg S, Sarno G, Girasis C, Vranckx P, de Vries T, Swart M, et al. Patient level pooled analysis assessing the impact of the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) Score on 1-year clinical outcomes in 6,508 patients enrolled in contemporary coronary stent trials. JACC Cardiovasc Intverv. 2011;4(6):645-53. Garg S Sarno G Girasis C Vranckx P de Vries T Swart M Patient level pooled analysis assessing the impact of the SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) Score on 1-year clinical outcomes in 6,508 patients enrolled in contemporary coronary stent trials JACC Cardiovasc Intverv 2011 4 6 645 653 15 Go AS, Mozaffarian D, Roger VL, Benjamin EJ, Berry JD, Borden WB, et al; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics--2013 update: a report from the American Heart Association. Circulation. 2013;127(1):e6-e245. Erratum in: Circulation. 2013;127(23):e841. Go AS Mozaffarian D Roger VL Benjamin EJ Berry JD Borden WB American Heart Association Statistics Committee and Stroke Statistics Subcommittee Heart disease and stroke statistics--2013 update: a report from the American Heart Association nullErratum in Circulation. 2013;127(23):e841. Circulation 2013 127 1 e6 e245 16 SYNTAX Working Group. SYNTAX score calculator. [Accessed in 2015 Nov 10]. Available from: http://www.syntaxscore.com SYNTAX Working Group SYNTAX score calculator 2015 Nov 10 Available from: http://www.syntaxscore.com 17 Thygesen K, Alpert JS, Jaffe AS, Simoons ML, Chaitman BR, White HD; Writing Group on the Joint ESC/ACCF/AHA/WHF Task Force for the Universal Definition of Myocardial Infarction. Third universal definition of myocardial infarction. Eur Heart J. 2012;33(20):2551-67. Thygesen K Alpert JS Jaffe AS Simoons ML Chaitman BR White HD Writing Group on the Joint ESC/ACCF/AHA/WHF Task Force for the Universal Definition of Myocardial Infarction Third universal definition of myocardial infarction Eur Heart J 2012 33 20 2551 2567 18 Murray CJ, Lopez AD, Feehan DM, Peter ST, Yang G. Validation of the symptom pattern method for analyzing verbal autopsy data. PLoS Med. 2007;4(11):e327. Murray CJ Lopez AD Feehan DM Peter ST Yang G Validation of the symptom pattern method for analyzing verbal autopsy data PLoS Med 2007 4 11 e327 19 Fleiss JL, Cohen J. The equivalence of weighted Kappa and the intraclass correlation coefficient as measures of reliability. Educational and Psychological Measurement. 1973;33:613-9. Fleiss JL Cohen J The equivalence of weighted Kappa and the intraclass correlation coefficient as measures of reliability Educational and Psychological Measurement 1973 33 613 619 20 Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig LM, et al. Standards for Reporting of Diagnostic Accuracy. The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration. Ann Intern Med. 2003;138(1):W1-12. Bossuyt PM Reitsma JB Bruns DE Gatsonis CA Glasziou PP Irwig LM Standards for Reporting of Diagnostic Accuracy. The STARD statement for reporting studies of diagnostic accuracy: explanation and elaboration Ann Intern Med 2003 138 1 W1 12 21 Riedner CE, Rhoden EL, Fuchs SC, Wainstein MV, Gonçalves SC, Wainstein RV, et al. Erectile dysfunction and coronary artery disease: an association of higher risk in younger men. J Sex Med. 2011;8(5):1445-53. Riedner CE Rhoden EL Fuchs SC Wainstein MV Gonçalves SC Wainstein RV Erectile dysfunction and coronary artery disease: an association of higher risk in younger men J Sex Med 2011 8 5 1445 1453 22 Mancini GB, Hartigan PM, Shaw LJ, Berman DS, Hayes SW, Bates ER, et al. Predicting Outcome in the COURAGE Trial: Coronary Anatomy Versus Ischemia. JACC Cardiovasc Interv. 2014;7(2):195-201. Mancini GB Hartigan PM Shaw LJ Berman DS Hayes SW Bates ER Predicting Outcome in the COURAGE Trial: Coronary Anatomy Versus Ischemia JACC Cardiovasc Interv 2014 7 2 195 201 23 Wallace EL, Abdel-Latif A, Charnigo R, Moliterno DJ, Brodie B, Matnani R, et al. Meta-analysis of long-term outcomes for drug-eluting stents versus bare-metal stents in primary percutaneous coronary interventions for ST-segment elevation myocardial infarction. Am J Cardiol. 2012;109(7):932-40. Wallace EL Abdel-Latif A Charnigo R Moliterno DJ Brodie B Matnani R Meta-analysis of long-term outcomes for drug-eluting stents versus bare-metal stents in primary percutaneous coronary interventions for ST-segment elevation myocardial infarction Am J Cardiol 2012 109 7 932 940 24 Garg S, Girasis C, Sarno G, Goedhart D, Morel MA, Garcia-Garcia HM, et al. SYNTAX trial investigators. The SYNTAX score revisited: a reassessment of the SYNTAX score reproducibility. Catheter Cardiovasc Interv. 2010;75(6):946-52. Garg S Girasis C Sarno G Goedhart D Morel MA Garcia-Garcia HM SYNTAX trial investigators. The SYNTAX score revisited: a reassessment of the SYNTAX score reproducibility Catheter Cardiovasc Interv 2010 75 6 946 952 25 Tanboga IH, Ekinci M, Isik T, Kurt M, Kaya A, Sevimli S. Reproducibility of syntax score: from core lab to real world. J Interv Cardiol. 2011;24(4):302-6. Tanboga IH Ekinci M Isik T Kurt M Kaya A Sevimli S Reproducibility of syntax score: from core lab to real world J Interv Cardiol 2011 24 4 302 306 26 Généreux P, Palmerini T, Caixeta A, Cristea E, Mehran R, Sanchez R, et al. SYNTAX score reproducibility and variability between interventional cardiologists, core laboratory technicians, and quantitative coronary measurements. Circ Cardiovasc Interv. 2011;4(6):553-61. Généreux P Palmerini T Caixeta A Cristea E Mehran R Sanchez R SYNTAX score reproducibility and variability between interventional cardiologists, core laboratory technicians, and quantitative coronary measurements Circ Cardiovasc Interv 2011 4 6 553 561 27 Nashef SA, Roques F, Michel P, Gauducheau E, Lemeshow S, Salamon R. European system for cardiac operative risk evaluation (EuroSCORE). Eur J Cardiothorac Surg. 1999;16(1):9-13. Nashef SA Roques F Michel P Gauducheau E Lemeshow S Salamon R European system for cardiac operative risk evaluation (EuroSCORE) Eur J Cardiothorac Surg 1999 16 1 9 13 28 Shroyer AL, Coombs LP, Peterson ED, Eiken MC, DeLong ER, Chen A, et al; Society of Thoracic Surgeons. The Society of Thoracic Surgeons: 30-day operative mortality and morbidity risk models. Ann Thorac Surg. 2003;75(6):1856-65. Shroyer AL Coombs LP Peterson ED Eiken MC DeLong ER Chen A Society of Thoracic Surgeons The Society of Thoracic Surgeons: 30-day operative mortality and morbidity risk models Ann Thorac Surg 2003 75 6 1856 1865 29 Metzler B, Winkler B. SYNTAX, STS and EuroSCORE - How good are they for risk estimation in atherosclerotic heart disease? Thromb Haemost. 2012:108(6):1065-71. Metzler B Winkler B SYNTAX, STS and EuroSCORE - How good are they for risk estimation in atherosclerotic heart disease? Thromb Haemost 2012 108 6 1065 1071 30 Windecker S, Kolh P, Alfonso F, Collet JP, Cremer J, Falk V, et al. 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)Developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Eur Heart J. 2014;35(37):2541-619. Windecker S Kolh P Alfonso F Collet JP Cremer J Falk V 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS)Developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI) Eur Heart J 2014 35 37 2541 2619 Syntax Escore e Eventos Cardíacos Adversos Maiores em Pacientes com Suspeita de Doença Arterial Coronariana: Resultados de um Estudo de Coorte em Hospital Universitário no Sul do Brasil Fuchs Felipe C. Ribeiro Jorge P. Fuchs Flávio D. Wainstein Marco V. Bergoli Luis C. Wainstein Rodrigo V. Zen Vanessa Kerkhoff Alessandra C. Moreira Leila B. Fuchs Sandra C. Hospital de Clínicas de Porto Alegre - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS - Brasil Correspondência: Felipe Costa Fuchs, Serviço de Cardiologia, Hospital de Clínicas de Porto Alegre. Rua Ramiro Barcelos, 2350, Santa Cecília. CEP 90035-903, Porto Alegre, RS - Brasil. E-mail: fcfuchs@terra.com.br

Contribuição dos autores

Concepção e desenho da pesquisa: Fuchs FC, Ribeiro JP, Fuchs FD, Wainstein MV, Moreira LB, Fuchs SC; Obtenção de dados: Fuchs FC, Wainstein MV, Bergoli LC, Wainstein RV, Zen V, Kerkhoff AC; Análise e interpretação dos dados e Revisão crítica do manuscrito quanto ao conteúdo intelectual importante: Fuchs FC, Ribeiro JP, Fuchs FD, Bergoli LC, Wainstein RV, Zen V, Kerkhoff AC, Moreira LB, Fuchs SC; Análise estatística e Redação do manuscrito: Fuchs FC, Ribeiro JP, Fuchs FD, Fuchs SC; Obtenção de financiamento: Ribeiro JP, Moreira LB, Fuchs SC.

Potencial conflito de interesse

Declaro não haver conflito de interesses pertinentes.

 Resumo Fundamento:

A importância da anatomia coronariana na predição de eventos cardiovasculares é bem conhecida. O uso de escores anatômicos tradicionais na cineangiocoronariografia de rotina, entretanto, não foi incorporado à prática clínica. O SYNTAX escore (SXescore) é um sistema de escore que estima a extensão anatômica da doença arterial coronariana (DAC). Sua capacidade para predizer desfechos com base na cineangiocoronariografia diagnóstica de base ainda não foi testada.

 Objetivo:

Avaliar o desempenho do SXescore para predizer eventos cardíacos adversos maiores (MACE) em pacientes encaminhados para cineangiocoronariografia diagnóstica.

 Métodos:

Coorte prospectiva de 895 pacientes com suspeita de DAC encaminhados para cineangiocoronariografia diagnóstica eletiva de 2008 a 2011, em hospital universitário no Brasil. Os pacientes tiveram seus SXescores calculados e foram estratificados em três categorias: 'sem DAC significativa' (n = 495); SXescoreBAIXO-INTERMEDIÁRIO: < 23 (n = 346); e SXescoreALTO: ≥ 23 (n = 54). O desfecho primário foi composto de morte cardíaca, infarto do miocárdio e revascularização tardia. Os desfechos secundários foram MACE e morte por todas as causas.

 Resultados:

Em média, os pacientes foram acompanhados por 1,8 ± 1,4 anos. Desfecho primário ocorreu em 2,2%, 15,3% e 20,4% nos grupos 'sem DAC significativa', SXescoreBAIXO-INTERMEDIÁRIO e SXescoreALTO, respectivamente (p < 0,001). Morte por todas as causas foi significativamente mais frequente no grupo de SXescoreALTO comparado ao grupo 'sem DAC significativa', 16,7% e 3,8% (p < 0,001), respectivamente. Após ajuste para fatores de confusão, todos os desfechos permaneceram associados com o SXescore.

 Conclusão:

O SXescore prediz independentemente MACE em pacientes submetidos a cineangiocoronariografia diagnóstica. Seu uso rotineiro nesse contexto poderia identificar pacientes de pior prognóstico.

 Palavras-chave: Doença da Artéria Coronariana / epidemiologia Probabilidade Cineangiografia Syntax Escore Estudos de Coortes Introdução

A importância da anatomia coronariana na predição de eventos cardiovasculares é conhecida há décadas, quando da publicação de estudos como o Registro CASS (Coronary Artery Study).1 Esse grande estudo de coorte mostrou a capacidade de escores anatômicos para doença arterial coronariana (DAC) para predizer eventos, mas seu uso rotineiro não foi incorporado à prática clínica.2 Atualmente, indica-se avaliação funcional e não invasiva de isquemia, como ecocardiografia de estresse, cintilografia miocárdica e ressonância magnética, para avaliar pacientes com DAC conhecida ou com suspeita dessa doença.3 No entanto, um significativo número de pacientes acaba sendo submetido a cineangiocoronariografia para confirmação diagnóstica.3 Consequentemente, a reavaliação do desempenho de escores anatômicos para predição de desfechos, em um contexto de novas terapias clínicas e intervencionistas, pode ter seu valor. Atualmente, o SYNTAX (Synergy between percutaneous coronary intervention with Taxus and Cardiac Surgery) Escore (SXescore), um método mais elaborado para quantificar lesões anatômicas, é uma ferramenta disponível online que estima a extensão anatômica da DAC.4

O SXescore é um abrangente sistema de escore angiográfico baseado na anatomia coronariana e nas características da lesão.4 Foi inicialmente desenvolvido para determinar a extensão da DAC e a complexidade da lesão, que refletem as dificuldades na realização da revascularização miocárdica, em particular da intervenção coronariana percutânea (ICP). No ensaio SYNTAX, valores altos de SXescore (acima de 33) identificaram pacientes nos quais a cirurgia de revascularização miocárdica resultou em melhores desfechos do que o de pacientes submetidos a revascularização percutânea.5 O seguimento de cinco anos desse ensaio identificou a cirurgia de revascularização miocárdica como sendo mais adequada para pacientes com escores acima de 22.6

O SXescore foi desenvolvido como uma ferramenta do processo de tomada de decisão, tendo sua utilização sido estendida mais tarde como escore de predição de eventos cardíacos adversos maiores (MACE) em pacientes submetidos a ICP.7-14 Tais estudos incluíram procedimentos de revascularização eletivos e de urgência. Entretanto, a maioria das cineangiocoronariografias é realizada com propósito diagnóstico.15 O desempenho prognóstico do SXescore nesse contexto ainda não foi relatado, constituindo o objetivo desta investigação.

 Objetivo

Avaliar o desempenho do SXescore para predição de MACE em pacientes encaminhados para cineangiocoronariografia diagnóstica.

 Métodos Desenho e população do estudo

Este estudo de coorte arrolou pacientes com suspeita de DAC encaminhados para cineangiocoronariografia diagnóstica eletiva de 2008 a 2011, em um hospital universitário terciário de referência (Hospital de Clínicas de Porto Alegre), no sul do Brasil. Os pacientes foram encaminhados por cardiologistas do sistema público de saúde e da prática privada, tendo sido submetidos a cateterização cardíaca devido a suspeita de DAC com ou sem exame não invasivo prévio para isquemia. Pacientes encaminhados para cineangiocoronariografia devido a suspeita de DAC e doença cardíaca valvular associada também foram incluídos. Homens e mulheres com idade mínima de 40 anos eram elegíveis para este estudo, excluindo aqueles com revascularização coronariana prévia (cirúrgica ou percutânea), insuficiência cardíaca classes III ou IV, doença renal crônica (diagnóstico médico prévio ou creatinina sérica superior a 1,5 mg/dl), história de câncer, ou enfermidade psiquiátrica grave. Os pacientes hospitalizados por síndrome coronariana aguda não foram incluídos.

 Arrolamento e procedimentos do estudo

O protocolo do estudo foi aprovado pelo Comitê de Ética em Pesquisa com Seres Humanos do hospital, tendo-se obtido termo de consentimento livre e informado. Entrevistas com informação demográfica, características de estilo de vida e história médica foram realizadas usando-se um questionário padronizado. Após as cineangiocoronariografias, coube aos médicos assistentes avaliar a necessidade de revascularização e todo o tratamento médico. O seguimento foi realizado de 2008 a 2012.

 SYNTAX escore e análise angiográfica

Os SXescores foram calculados prospectivamente com todas as lesões coronarianas que produzissem uma estenose de diâmetro ≥ 50% nos vasos ≥ 1,5 mm, usando o algoritmo disponível no website do SYNTAX escore.16 Subsequentemente, foram categorizados como se segue: SXescoreALTO (≥ 23); SXescoreBAIXO-INTERMEDIÁRIO (< 23); e 'sem DAC significativa' (categoria de referência). Dois cardiologistas intervencionistas (FCF, LCCB) realizaram independentemente a análise angiográfica visual para avaliação do escore. Foram treinados para calcular o SXescore usando o tutorial do website. Em seguida, eles atribuíram escore a outros 80 casos, que foram exaustivamente discutidos com cardiologistas intervencionistas seniores. Avaliou-se a concordância inter- e intraobservador para determinação do SXescore em outro grupo de 90 cineangiocoronariografias.

 Desfechos do estudo

O desfecho primário foi MACE, definido como o tempo até o primeiro evento (morte cardíaca, infarto do miocárdio (IM) ou revascularização tardia). Infarto do miocárdio e revascularização seguidos de morte na mesma hospitalização foram adjudicados como morte cardíaca, assim como morte súbita. O IM foi diagnosticado por aumento de biomarcadores, na presença de sintomas e anormalidades eletrocardiográficas sugestivas de isquemia.17 Alguns pacientes foram tratados para IM agudo em outros hospitais, sendo o diagnóstico definido com base no diagnóstico de alta. A revascularização tardia foi ICP ou cirurgia de revascularização miocárdica.

Revascularizações percutâneas e cirúrgicas, tendo por base achados de cineangiocoronariografia diagnóstica, realizadas até três meses após a cineangiocoronariografia, foram definidas como procedimentos-índice e não considerados desfechos. As intervenções realizadas durante o seguimento, não diretamente relacionadas à cineangiocoronariografia diagnóstica, foram definidas como revascularizações tardias e incluídas no desfecho primário. Os desfechos secundários foram morte cardíaca, morte cardiovascular (IM fatal ou acidente vascular encefálico), IM, revascularização coronariana e mortalidade global.

Todas as mortes foram confirmadas por necropsia verbal,18 declaração de óbito (fornecida pelo Ministério da Saúde, que detém todos os registros de óbito dos estados) ou registro hospitalar. O IM foi estabelecido por hospitalização, com diagnóstico informado por médico. Um Comitê de Eventos Clínicos independente adjudicou todos os desfechos. A coleta de dados referentes aos desfechos foi submetida a controle de qualidade para verificar confiabilidade, tendo outro investigador checado 5% das necropsias verbais.

 Cálculo do tamanho amostral e análise estatística

Os questionários foram codificados e passados para um banco de dados usando o programa Epinfo 2004 (versão 3.3.2, Centro para Controle e Prevenção de Doença, Atlanta, EUA), com controle de qualidade da entrada de dados para verificar amplitude e consistência. Um tamanho amostral de 588 participantes seria necessário para identificar uma razão de risco (hazard ratio - HR) de pelo menos 2,4, com poder de 80% e nível de significância de 5% (bicaudal), considerando que 5% de não expostos e 12% de expostos ao mais alto escore, uma taxa de 1:1,5, respectivamente, apresentariam um desfecho primário. Considerando a ausência de relato prévio sobre o desempenho do SXescore para predizer eventos nesse contexto, aumentou-se o tamanho amostral para 906 participantes para incluir um número suficiente de pacientes com escores altos (> 23) para fornecer poder estatístico adequado. Epi Info 2004, Statcalc module, foi usado para calcular o tamanho amostral.

A confiabilidade inter- e intraobservador foi avaliada através de checagem cruzada de 90 angiogramas analisados por dois cardiologistas intervencionistas e revisados por um terceiro. O coeficiente kappa foi usado para avaliar concordância, com interpretação segundo Fleiss et al.19 Concordância substancial foi definida como coeficiente kappa de 0,7, considerando-se a proporção de pacientes com SXescore > 23, sendo 30% segundo o observador 1 e 20% segundo o observador 2, com acurácia de 0,2. Os coeficientes de correlação intraclasse também foram calculados.

As recomendações STARD20 foram usadas para planejar e relatar este estudo. Os dados foram apresentados como média ± desvio padrão (DP), porcentagens e HR com intervalo de confiança (IC) de 95%. Usou-se curva ROC (Receiver Operating Characteristic) para calcular a estatística C e a área sub a curva. A curva de sobrevida de Kaplan-Meier para MACE foi calculada para pacientes de acordo com os SXescores. Realizou-se análise multivariada do poder de predição do SXescore usando regressão de Cox, que permitiu a estimativa de HR e IC 95%. As variáveis associadas com o desfecho na análise bivariada (p ≤ 0,2) foram elegíveis como fatores de confusão. Considerando que muitas variáveis são intermediárias na causa de MACE, elas foram avaliadas individualmente quanto à sua inclusão na análise. Usou-se o mesmo modelo para o número de vasos comprometidos (nenhum, um e múltiplos) como variável de exposição. As análises foram realizadas com o programa Statistical Package for Social Sciences (SPSS(r), versão 17, Chicago, IL, EUA), adotando-se o valor de p < 0,05 como estatisticamente significativo.

 Resultados

O fluxograma do estudo é apresentado na Figura 1. Dos 928 pacientes elegíveis, 895 com SXescore foram incluídos na coorte e acompanhados em média por 1,8 ± 1,4 anos. Após a cineangiocoronariografia, 314 (35,1%) pacientes foram submetidos a ICP ou cirurgia de revascularização miocárdica, e 82 (9,2%), a substituição de válvula (procedimento-índice). Novas intervenções foram realizadas durante o seguimento (revascularizações tardias) em 54 pacientes (35 percutâneas e 19 cirúrgicas). Infarto do miocárdio ocorreu em 16 pacientes, morte cardíaca em 13, morte cardiovascular em 22, e morte por todas as causas em 40 pacientes. Estabeleceu-se a presença de MACE em 73 pacientes.

Fluxograma dos pacientes do estudo. ICP: intervenção coronariana percutânea; CRM: cirurgia de revascularização miocárdica; IM: infarto do miocárdio; DAC: doença arterial coronariana; CV: cardiovascular; MACE: eventos cardíacos adversos maiores.* Pacientes de substituição valvar foram excluídos da análise de desfecho. <sup>Ŧ</sup> MACE como definido na seção Métodos.

O coeficiente de correlação de Spearman entre os SXescores calculados pelos dois cardiologistas intervencionistas foi 0,902 (p < 0,001), sendo a concordância interobservador entre eles de 0,94 (IC 95%: 0,91-0,96). O coeficiente Kappa foi 0,83 para os dois cardiologistas intervencionistas. Houve 495 pacientes com escore de 0 (55,4%) e 400 (44,6%) com escores positivos, variando de 1 a 43, com média de 12,6 (IC 95%: 11,7-13,4). Os pacientes com lesões coronarianas com estenose de diâmetro ≥ 50% em vasos ≥1,5 mm foram classificados como SXescoreBAIXO-INTERMEDIÁRIO (n = 345) ou SXescoreALTO (n = 54).

As características clínicas e angiográficas basais conforme as categorias dos pacientes são apresentadas na Tabela 1. A idade média dos pacientes com SXescoreALTO foi mais elevada do que aquela dos pacientes com SXescoreBAIXO-INTERMEDIÁRIO. Além disso, a proporção de pacientes do sexo masculino, com diabetes mellitus e hipertensão foi maior entre aqueles com SXescoreALTO. As indicações clínicas para cineangiocoronariografia diagnóstica não diferiram significativamente conforme o SXescore, ainda que maior número de pacientes com SXescoreBAIXO-INTERMEDIÁRIO tivesse sintomas típicos de DAC, e maior número de pacientes 'sem DAC significativa' apresentasse outros sintomas. Como esperado, a prevalência de doença multiarterial e de todos os marcadores para lesão de alta complexidade, como oclusão total, bifurcações e doença de pequenos vasos, foi significativamente maior na categoria de SXescoreALTO.

Características clínicas basais segundo as categorias de SXescore dos pacientes
Características basais Sem DAC significativa n = 495 SXescoreBAIXO-INTERMEDIÁRIO n = 346 SXescoreALTO n = 54 Valor de p
Idade 59,1 ± 10,4 60,8 ± 9,6 63,6 ± 8,6 0,002
Masculino 234 (47,3) 226 (65,3) 39 (72,2) < 0,001
Diabetes mellitus 92 (18,6) 85 (24,6) 18 (33,3) 0,01
Tabagismo atual 65 (13,2) 51 (15,0) 3 (5,6) 0,08
Hipertensão 344 (69,8) 260 (76,5) 45 (83,3) 0,02
Apenas sintomas sugestivos de DAC 128 (25,9) 115 (33,4) 14 (25,9) 0,05
Com teste não invasivo positivo 209 (42,2) 139 (40,2) 28 (51,9) 0,3
Valvopatia com suspeita de DAC 14 (2,8) 3 (0,9) 1 (1,9) 0,14
Outras queixas 46 (9,3) 13 (3,8) 1 (1,9) 0,002
Análise angiográfica*
Dominância direita - 309 (89,3) 51 (94,4) 0,3
No. lesões por paciente - 1,8 ± 1,0 3,9 ± 1,5 < 0,001
Oclusão total - 88 (25,4) 41 (75,9) < 0,001
Bifurcações - 125 (36,1) 44 (81,5) < 0,001
Pequenos vasos/doença difusa - 68 (19,7) 26 (48,1) < 0,001
Tronco de coronária esquerda - 13 (13,8) 13 (24,1) < 0,001
Descendente anterior esquerda - 218 (63,0) 47 (87,0) < 0,001
Circunflexa - 109 (31,5) 36 (66,7) < 0,001
Coronária direita - 169 (48,8) 43 (79,6) < 0,001
Doença uniarterial - 196 (56,7) 4 (7,4) < 0,001
Doença multiarterial ou tronco - 150 (43,3) 50 (92,6) < 0,001

Valores apresentados como n (%) ou média ± DP. DAC: doença arterial coronariana; SXescore: Syntax Escore.

Avaliação usando as definições do SYNTAX Escore

 Procedimentos após a cineangiocoronariografia-índice

A proporção de pacientes submetidos a ICP, cirurgia de revascularização miocárdica e substituição valvar com base na cineangiocoronariografia-índice diagnóstica, de acordo com a categoria do paciente, é apresentada na Tabela 2. Como esperado, maior número de pacientes com escores altos foi submetido a cirurgia de revascularização miocárdica. Ainda que, na avaliação angiográfica de base realizada neste estudo, tenham sido classificados como 'sem DAC significativa', 3,4% desses pacientes foram submetidos a ICP.

Tratamento após cineangiocoronariografia-índice e desfechos clínicos cumulativos segundo as categorias de SXescore dos pacientes
Tipo de procedimento Sem DAC significativa n = 495 SXescorenBAIXO-INTERMEDIÁRIO n = 346 SXescoreALTO n = 54 Valor de p
Intervenções < 0,001
Intervenção coronariana percutânea 17 (3,4) 208 (60,3) 14 (25,9)
Cirurgia de revascularização miocárdica 0 46 (13,3) 29 (53,7)
Substituição valvar isolada* 78 (15,8) 4 (1,2) 0
Sem intervenção invasiva 400 (80,8) 88 (25,4) 11 (20,4)
Morte por todas as causas 16 (3,9) 11 (3,3) 9 (16,7) < 0,001
Morte cardíaca e IM 4 (1,0) 13 (3,9) 9 (16,7) < 0,001
Morte cardiovascular 9 (2,2) 6 (1,8) 7 (13) < 0,001
MACE 9 (2,2) 53 (15,7) 11 (20,4) < 0,001

Valores apresentados como n (%).

pacientes excluídos da análise de desfecho. DAC: doença arterial coronariana; IM: infarto do miocárdio; MACE: eventos cardíacos adversos maiores; IM: morte cardíaca e revascularização tardia.

 Desfechos clínicos

A incidência cumulativa de desfechos clínicos nos grupos é apresentada na Tabela 2. Morte por todas as causas foi significativamente mais alta em pacientes com SXescoreALTO quando comparados àqueles do grupo 'sem DAC significativa', 16,7% e 3,9% (p < 0,001), respectivamente. Morte cardiovascular, IM não fatal e revascularização tardia foram mais frequentes no grupo com SXescoreALTO. Após ajuste para fatores de confusão, todos os desfechos permaneceram associados com o SXescore (Tabela 3). As HR para MACE, morte cardíaca ou IM não fatal e IM não fatal apenas mostraram-se significativamente associadas a SXescoreBAIXO-INTERMEDIÁRIO. Os pacientes da categoria SXescoreALTO apresentaram uma chance 12,5 vezes maior (IC 95%: 5,1-30,6) de desfecho primário do que aqueles 'sem DAC significativa'. Tal achado foi semelhante em homens (10,1; IC 95%: 3,9-25,9) e mulheres (11,5; IC 95%: 1,1-117,3). Ajuste posterior para revascularização-índice não alterou as estimativas de maneira significativa. Após ajuste para os fatores de confusão, o desfecho primário também se associou ao SXescore como uma variável contínua (HR 1,06; IC 95%: 1,04-1,08). A área sob a curva ROC foi de 0,73 (IC 95%: 0,68-0,79) (Figura 2).

Razão de risco (HR)<xref ref-type="table-fn" rid="TFN14">*</xref> para desfechos clínicos maiores segundo as categorias de SXescore dos pacientes
Tipo de evento Sem DAC significativa † n = 495 SXescoreBAIXO-INTERMEDIÁRIO n = 346 SXescoreALTO n = 54 Valor de p
Morte por todas as causas 1,0 0,8 (0,4-1,7) 4,3 (1,8-10,1) < 0,001
Morte cardiovascular 1,0 0,7 (0,3-2,1) 5,7 (2,0-15,9) < 0,001
Morte cardíaca 1,0 1,3 (0,3-5,9) 11,8 (2,9-48,5) < 0,001
MACE‡ 1,0 7,2 (3,5-14,7) 12,5 (5,1-30,6) < 0,001
Morte cardíaca ou IM 1,0 3,5 (1,1-10,8) 16,0 (4,9-52,9) < 0,001
IM 1,0 12,6 (1,6-98,3) 33,9 (3,7-308,0) 0,007
Revascularização tardia 1,0 9,9 (4,2-23,4) 4,0 (0,8-20,0) < 0,001

DAC: doença arterial coronariana; IM: infarto do miocárdio; MACE: eventos cardíacos adversos maiores.

Ajustada para idade, sexo e diabetes.

Categoria de referência.

MACE: IM, morte cardíaca e revascularização tardia.

Curva ROC para o SYNTAX Escore. AUC: área sob a curva.

As curvas de sobrevida sem MACE para os pacientes de acordo com os SXescores são apresentadas na Figura 3. Pode-se ver que as curvas divergiram imediatamente após a cineangiocoronariografia e mais ainda durante o seguimento. As HR para MACE de acordo com o número de vasos comprometidos, em comparação a nenhum vaso, foram 6,9 (IC 95%: 3,4-13,9) para doença uniarterial e 10,2 (5,2-20,1) para doença multiarterial. A despeito da relação intrínseca dessa classificação com o SXescore, 42,0% dos pacientes com doença multiarterial foram classificados na categoria de SXescoreBAIXO-INTERMEDIÁRIO.

Curva de Kaplan-Meier para eventos cardíacos adversos maiores (MACE) de acordo com a categoria do SYNTAX Escore (SXescore) do paciente. DAC: doença arterial coronariana.

Discussão

Este estudo demonstrou que, em pacientes submetidos a cineangiocoronariografia diagnóstica devido a suspeita de DAC, o SXescore pôde predizer o desfecho primário de morte cardíaca, IM não fatal e revascularização tardia, independentemente de idade, sexo, presença de diabetes e revascularização-índice. Houve aumento de 6% no risco de MACE para cada ponto adicional no escore. Os pacientes com SXescoreALTO apresentaram um risco significativamente elevado de morte por todas as causas, cardiovascular e cardíaca.

Estudos prévios relataram a capacidade do SXescore para predizer MACE em diferentes cenários. Os estudos LEADERS,9,10 SIRTAX11 e RESOLUTE8 incluíram pacientes com síndromes coronarianas agudas e ainda aqueles submetidos a ICP eletiva. Os estudos MI-SYNTAXscore,12 STRATEGY e MULTISTRATEGY13 foram realizados em pacientes com IM agudo. O ensaio ACUITY7 incluiu pacientes com síndromes coronarianas agudas. Por fim, Garg et al.14 resumiram os resultados de cinco estudos, analisando dados de 6.508 pacientes, com os mesmos resultados. Diferentemente da nossa pesquisa, todos aqueles estudos incluíram apenas pacientes submetidos a procedimentos de revascularização percutânea, nenhum deles tendo focado em pacientes com suspeita de DAC ou com DAC estável. O grupo de pacientes 'sem DAC significativa', ainda que muitos tivessem DAC com estenose de diâmetro inferior a 50%, serviu como categoria de referência para comparar os desfechos com os de pacientes nas categorias SXescoreBAIXO-INTERMEDIÁRIO e SXescoreALTO. Sabemos ser nossa proposta diferente da aplicação original do escore, na qual pacientes sem lesões tratáveis por cirurgia ou por via percutânea foram excluídos, mas alinha-se com os objetivos deste estudo.

A comparação do desempenho do SXescore com escores anatômicos tradicionais para DAC não foi explorada na nossa investigação. A presença de SXescores positivos (44,6%) foi similar à frequência de pacientes com DAC significativa (47%) detectada por análise angiográfica quantitativa realizada em uma proporção de pacientes da nossa coorte.21 Escores angiográficos tradicionais também predisseram a incidência de MACE em estudos prévios,2 mas tais escores não consideram as dificuldades da realização de revascularização miocárdica. A despeito de sua capacidade prognóstica, eles não foram incorporados à prática clínica, na qual o número de vasos comprometidos foi usado para estimar a gravidade anatômica da doença. Nesta coorte, os pacientes com doença uniarterial e multiarterial apresentaram risco de MACE aproximadamente similar ao dos pacientes com SXescoreBAIXO-INTERMEDIÁRIO e SXescoreALTO, respectivamente. No entanto, quase metade dos pacientes com doença multiarterial foi classificada na categoria SXescoreBAIXO-INTERMEDIÁRIO.

Com base nos resultados do estudo SYNTAX,5 no qual pacientes com baixos escores SYNTAX apresentaram desfechos similares a despeito do tipo de revascularização, nossos achados têm uma implicação clínica - pacientes que, de outra maneira, seriam encaminhados para cirurgia de revascularização miocárdica também poderiam ser revascularizados por via percutânea. Considerando que a caracterização visual de doença multiarterial leva ao encaminhamento de pacientes para revascularização cirúrgica, o cálculo do SXescore poderia melhor estratificar pacientes que de fato se beneficiariam daquele procedimento (categoria SXescoreALTO).

Neste estudo, os pacientes foram submetidos a procedimento eletivo e, como resultado, houve uma grande proporção de pacientes 'sem DAC significativa', que também poderiam ter lesões menores do que 50%. Tais pacientes não preenchiam os critérios para um escore positivo e serviram como grupo de comparação. Assim, os pacientes foram classificados em duas categorias: 1 a 22, e igual ou maior do que 23, correspondendo às posteriormente definidas categorias 'baixo-intermediário' (0-22) e 'alto' (igual ou maior do que 23).6 O número de pacientes classificados como SXescoreBAIXO-INTERMEDIÁRIO e submetidos a revascularização percutânea foi maior do que o de pacientes submetidos a revascularização cirúrgica, refletindo a prática clínica corrente e em conformidade com os achados de acompanhamento de cinco anos do ensaio clínico randomizado SYNTAX.6 Na época em que o estudo foi conduzido, os stents farmacológicos não eram disponíveis para uso no sistema de saúde pública brasileiro. Além disso, atualmente indica-se revascularização cirúrgica para pacientes com SXescore alto.6 Pacientes com alto risco cirúrgico, considerados inelegíveis para revascularização cirúrgica pelos cirurgiões receberam tratamento percutâneo. Houve um achado inesperado de 3,4% de pacientes 'sem DAC significativa' submetidos a ICP. Pacientes com DAC não obstrutiva representam uma grande proporção daqueles submetidos a cineangiocoronariografia. A avaliação subjetiva da anatomia coronariana associada a informação clínica e não invasiva pode ter influenciado o processo de tomada de decisão e poderia explicar tal achado.

Nosso estudo tem algumas limitações e pontos fortes que devem ser abordados. Restringimos nossa análise ao critério anatômico, sem considerar função ventricular esquerda, isquemia ou viabilidade miocárdica. No entanto, nossos pacientes não tinham doença instável do ponto de vista clínico e nem insuficiência cardíaca classe III ou IV, tendo os critérios anatômicos frequentemente prevalecido para a tomada de decisão terapêutica. Além disso, uma recente análise post-hoc do ensaio COURAGE demonstrou que os critérios anatômicos e não a carga isquêmica foram capazes de predizer eventos cardiovasculares.22 Embora a maioria dos procedimentos de seguimento tenha sido realizada em nosso hospital, diferentes tipos de stent foram implantados, o que pode ter afetado a probabilidade de trombose no stent ou de reintervenções.23 Entretanto, análise incluindo apenas IM e morte cardíaca não alterou as estimativas, e a exclusão de pacientes submetidos a substituição valvar não alterou os resultados. Outra limitação é o número de eventos, responsável pelos amplos intervalos de confiança. Ainda que tivéssemos investigado quase 1.000 pacientes, mais de 50% não tinham DAC significativa, refletindo a prática da vida real de um centro terciário que realiza cineangiocoronariografias diagnósticas. Estudos com maiores tamanhos amostrais e conduzidos em outros centros são necessários para confirmar nossos achados e sua validade externa. A alta reprodutibilidade interobservador dos examinadores é um dos pontos fortes da nossa investigação, semelhante à de alguns estudos,24 mas diferente da de outros.25,26 Tal desempenho poderia ser explicado pelo extenso treinamento na avaliação do SXescore realizado pelos cardiologistas intervencionistas e o fato de que ambos foram treinados no mesmo hospital.

Implicações clínicas

Na prática clínica, o número de vasos epicárdicos com estenose superior a 50% é usado para fornecer informação prognóstica, sendo os escores angiográficos raramente usados. Recentemente, o uso de escores mostrou melhorar a padronização da tomada de decisão clínica. Por exemplo, o EUROESCORE27 e o escore STS28 são usados de rotina no processo de tomada de decisão para a indicação de cirurgia de revascularização miocárdica.29 Para a conduta em DAC multiarterial, as atuais diretrizes formalmente recomendam o uso do SXescore, assim como do EUROESCORE.30 Nossos dados expandem as indicações do SXescore para avaliação prognóstica de pacientes encaminhados para cineangiocoronariografia diagnóstica.

 Conclusão

Em pacientes com suspeita de DAC submetidos a cineangiocoronariografia eletiva, o SXescore prediz independentemente MACE. Seu uso rotineiro nesse contexto poderia identificar pacientes com pior prognóstico.

(in memorian)

Fontes de financiamento

O presente estudo foi parcialmente financiado pelo CNPq e Fundação para o incentivo em Pesquisa do Hospital de Clínicas de Porto Alegre.

Vinculação acadêmica

Este artigo é parte de Dissertação de Mestrado de Felipe C. Fuchs pela Faculdade de Medicina da Universidade Federal do Rio Grande do Sul.

 Agradecimentos

Este estudo foi parcialmente financiado pelo Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brasil; Fundo de Pesquisa do Hospital de Clínicas de Porto Alegre (FIPE-HCPA), Porto Alegre, Brasil.