dic ABC Imagem Cardiovascular Arq Bras Cardiol: Imagem cardiovasc 2675-312X Sociedade Brasileira de Cardiologia 10.36660/abcimg.20230052i Review Article My Approach to Myocardial Work: Why and for Whom? 0000-0001-6421-3505 Lustosa Rodolfo de Paula Conception and design of the research writing of the manuscript and critical revision of the manuscript for intellectual content 1 2 3 0000-0002-2959-1874 Rabischoffsky Arnaldo Conception and design of the research writing of the manuscript and critical revision of the manuscript for intellectual content 2 4 0000-0002-0477-480X Gripp Eliza de Almeida Conception and design of the research writing of the manuscript and critical revision of the manuscript for intellectual content 4 5 Hospital Copastar Rio de Janeiro RJ Brazil Hospital Copastar, Rio de Janeiro, RJ – Brazil Hospital Américas Medical City Rio de Janeiro RJ Brazil Hospital Américas Medical City, Rio de Janeiro, RJ – Brazil Hospital Quinta D’Or Rio de Janeiro RJ Brazil Hospital Quinta D’Or, Rio de Janeiro, RJ – Brazil Hospital Pró-Cardíaco Rio de Janeiro RJ Brazil Hospital Pró-Cardíaco, Rio de Janeiro, RJ – Brazil Hospital Universitário Antônio Pedro UFF Rio de Janeiro RJ Brazil Hospital Universitário Antônio Pedro (UFF), Rio de Janeiro, RJ – Brazil Mailing Address: Rodolfo de Paula Lustosa • Américas Medical City, Ecocardiografia. Av Jorge Curi, 550. Postal code: 22275-001. Rio de Janeiro, RJ - Brazil E-mail: rodolfolustosarj@gmail.com

Potential Conflict of Interest

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

Editor responsible for the review: Daniela do Carmo Rassi Frota

 26 07 2023 07 2023 36 3 e20230052 2 06 2023 2 06 2023 2 06 2023 This is an open-access article distributed under the terms of the Creative Commons Attribution License Abstract

The emergence of a new noninvasive tool known as myocardial work (MW) for assessing ventricular function, which is independent of load conditions, has been fundamental in advancing current imaging methods, such as myocardial strain. Strain is considered a sensitive technique in the detection of subclinical dysfunction, even though it is still dependent on load conditions, making it impossible to differentiate contractile alteration from interference caused by increased afterload alone. This new technology incorporated into myocardial strain will increase the sensitivity of the method.

: My Approach to Myocardial Work: Why and for Whom? Calculation of left ventricular GWE, in a 17-segment model showing GWE segmental values. Preserved segmental GWE values are shown in green and expressed in %. The patient’s GWI, GCW, GWW, GWE, and blood pressure values are shown in white. GCW: global constructive work; GWE: global work efficiency; GWI: global work index; GWW: global wasted work (Source: Author).

Introduction

The concept of pressure-volume curves has been widely used in cardiovascular physiology and assessment of cardiac function.1 - 3 Experimental studies have demonstrated that it is possible to assess the global performance of the ventricles by means of a contractility index that is independent of load conditions. This concept has not yet become the “gold standard” in clinical practice and research, because invasive techniques are still required to determine these curves. However, studies have shown that the noninvasive estimation of these curves is a strong predictor of events regardless of left ventricular ejection fraction (LVEF), as demonstrated in the study by Spevack et al.4

My approach

According to the same principle as pressure-volume curves, the concept of noninvasive evaluation of myocardial work (MW) was published by Russell et al. in 2012.5 According to the authors, the determination of pressure-strain loop area by means of Doppler echocardiography would reflect MW and oxygen consumption. Currently, the calculation of MW by Doppler echocardiography is performed using commercially available software (EchoPac, GE Medical Systems). MW indices are estimated by combining noninvasive estimation of peak left ventricular (LV) pressure using blood pressure measurements with a sphygmomanometer (in which peak LV systolic pressure is assumed to be equal to systolic arterial pressure) associated with echocardiographic data from strain curves.

After calculating the strain and inserting the blood pressure values obtained by sphygmomanometer, the opening and closing times of the aortic and mitral valves are identified by echocardiogram in the apical 3-chamber view. A LV pressure-strain curve is then constructed with strain data from the entire cardiac cycle, according to the duration of relaxation and isovolumetric contraction, the ejection and filling phases defined by the opening and closing times of the aortic and mitral valves, and blood pressure values.6

LV work is calculated as a product of the segmental shortening rate and the instantaneous LV pressure. The following indices are derived from measurements of cardiac work by echocardiography (Central Figure):

Global work index (GWI): total work calculated from mitral valve closure to mitral valve opening, representing the area of the loop provided by the software (expressed in mmHg%);

Global constructive work (GCW): work performed by a segment during systolic shortening added to work performed during diastolic lengthening, representing the work that contributes to myocardial contractility (expressed in mmHg%);

Global wasted work (GWW): negative work performed by a segment during lengthening in systole added to the work performed during shortening in diastole, which represents the work that does not contribute to myocardial contractility (expressed in mmHg%);

Global work efficiency (GWE): GCW divided by the sum of GCW and GWW, representing the measure of LV performance (expressed in %).

The mean reported normal values7 for GWI and GCW are 2010 mmHg% (95% confidence interval [CI]: 1907 to 2113 mmHg%) and 2278 mmHg% (95% CI: 2186 to 2369 mmHg%), respectively. The mean for GWW is 80 mmHg% (95% CI: 73 to 87 mmHg%), and for GWE it is 96% (95% CI: 96% to 96%). The differences between men and women significantly contribute to the normal ranges for GWI, GWW and GWE.

 Applicability Ischemic heart disease

The use of MW in coronary artery disease can be divided into the context of acute coronary syndromes and chronic coronary artery disease. Moreover, global values are relevant, as are regional values derived from the software. In patients with acute ST-segment elevation myocardial infarction (STEMI), the study by El Mahdiui et al.8 provided evidence that GWE was reduced in patients with heart failure with reduced ejection fraction (HFrEF) after STEMI, compared to healthy individuals and those with risk factors for cardiovascular disease. A study by Lustosa et al.9 demonstrated, in a cohort of 600 patients after STEMI, that cardiac work indices were reduced 3 months after the index event in patients who had ventricular remodeling. The same author demonstrated that reduced GWE values (< 86%) measured by transthoracic Doppler echocardiography in the first 48 hours of STEMI admission would be associated with worse prognosis.10 The study by Meimoun et al.11 demonstrated that, in patients with STEMI previously treated with percutaneous coronary intervention, GCW was an independent factor for global and segmental LV recovery, and it was significantly reduced in patients who had in-hospital complications.

In the context of regional assessment of MW, the study by Boe et al.12 demonstrated that the presence of reduced regional GWI values could identify coronary occlusion in patients with acute non-ST-segment elevation myocardial infarction (NSTEMI). A study by Lustosa et al.,13 using regional GWI values, demonstrated that reduced regional GWI values in the territory of the culprit artery were independently associated with early cardiac remodeling.

MW has also been studied in chronic coronary artery disease. A study by Edwards et al.14 evaluated 115 patients with normal LVEF referred for coronary angiography due to different indications and demonstrated that GWI values less than 1810 mmHg% were predictive of significant coronary artery disease (defined by stenosis above 70%), with a sensitivity of 92% and specificity of 51%. A study by Borrie et al.15 demonstrated that MW indices can be used in stress echocardiography to identify myocardial ischemia.

 Cardiomyopathies

The main role of MW analysis in clinical practice for evaluating patients with cardiomyopathies focuses on patients with dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), and cardiac amyloidosis. The study by Chan et al.16 observed the difference between MW indices in patients with hypertension and DCM (19 non-ischemic and 10 ischemic). The authors reported that GWI, GCW, and GWE were significantly reduced, and GWW was significantly increased in patients with DCM compared to the control group. A study by Schrub et al.17 investigated the relationship between MW analysis and exercise tolerance in 51 patients with DCM who underwent a cardiopulmonary exercise test to assess exercise performance and reported that, in patients with DCM and intraventricular dyssynchrony, septal work efficiency was the only predictor of exercise capacity in the multivariate analysis (β = 0.68, p = 0.03). A study by Cui et al.18 compared MW indices in 30 patients with DCM and 30 healthy patients, finding significantly reduced values of MW indices in the DCM group compared to the control group (p < 0.05).

In 2019, Galli et al.19 studied 82 patients with non-obstructive HCM who underwent MW assessment. Patients also underwent cardiac magnetic resonance imaging to estimate LV fibrosis with delayed gadolinium enhancement. The authors reported that GCW is significantly reduced in patients with HCM and normal LVEF, and a cutoff value of 1623 mmHg% demonstrated a sensitivity of 82% and specificity of 67% to predict LV fibrosis in this population (area under the curve [AUC] 0.80, 95% CI: 0.66 to 0.93, p < 0.001). A study by Hiemstra et al.20 reported the prognostic role of MW analysis in 110 patients with non-obstructive HCM. Patients with GCW > 1730 mmHg% had better survival compared to those with GCW < 1730 mmHg% (log-rank 11.2, p = 0.001).

The value of the clinical application of MW indices in patients with cardiac amyloidosis has been reported by Clemmensen et al.21 The authors’ objective was to characterize resting and peak MW during exercise in patients with cardiac amyloidosis. They observed that patients with cardiac amyloidosis showed significantly reduced MW index values, and this difference was more evident during exercise compared to healthy subjects. In another study, the prognostic implications of MW analysis were demonstrated in 100 patients with cardiac amyloidosis.22 Patients with GWI < 1043 mmHg% had a higher number of events than patients with GWI > 1043 mmHg% (hazard ratio [HR] 2.3, 95% CI: 1.2 to 4.3, p = 0.01). Furthermore, patients with GWI < 1039 mmHg% had a higher risk of all-cause mortality than patients with GWI > 1039 mmHg% (HR 2.6, 95% CI: 1.2 to 5.5, p < 0.05).

 HFrEF and response to cardiac resynchronization therapy (CRT)

The first reports in clinical practice on the application of MW in patients with HFrEF were published in 2013. In an experimental study, Russell et al.23 evaluated the WW ratio (WWR) in 6 anesthetized dogs with left bundle branch block (LBBB) and 28 patients with cardiomyopathy, including patients with LBBB and CRT. The study demonstrated a strong correlation between invasively and noninvasively estimated WWR in dogs (r = 0.94) and patients (r = 0.96), with higher global WWR values in patients with LBBB. The study by Galli et al.24 estimated GCW and GWW in 97 patients before CRT and at 6-month follow-up. The authors showed that the addition of GCW > 1057 mmHg% and GWW > 384 mmHg% to a baseline model significantly increased the model’s power to identify CRT responders. The authors reported good specificity (100%) and positive predictive value (100%), but low sensitivity (22%), negative predictive value (41%), and accuracy (49%). In another study,25 the authors also showed, in 97 patients undergoing CRT implantation, that GCW > 1057 mmHg% (odds ratio [OR] 14.69, p = 0.005) and septal flash (OR 8.05, p = 0.004) were the only predictors of response to CRT. The study by Cvijic et al.26 calculated segmental MW in 26 patients with sinus rhythm and non-ischemic cardiomyopathy. Before CRT, work was unevenly distributed with reduced work in the septal and anteroseptal walls and increased work in the lateral and posterior walls (p < 0.001). The authors showed that, after CRT, the segmental distribution of work was uniform. MW asymmetry between the septal segments and the lateral wall was also observed in a prospective multicenter study with 200 patients.27 The authors showed that the lateral wall-septum work difference predicted the CRT response with an AUC of 0.77 (95% CI: 0.70 to 0.84); when combined with assessment of septal viability by cardiac magnetic resonance, the AUC increased to 0.88 (95% CI: 0.81 to 0.95). The prognostic importance of calculating MW in patients with heart failure was demonstrated by Van der Bijl et al.28 in a cohort of patients with class I indications for CRT. The authors demonstrated that patients with lower energy efficiency (GWE < 75%) before CRT demonstrated a lower rate of events than patients with higher energy efficiency (GWE > 75%). Bouali et al.29 investigated the effects of treatment with sacubitril/valsartan on MW indices in 79 patients with HFrEF and reported that the treatment significantly increased GCW (1023 ± 449 mmHg% to 1424 ± 484 mmHg%, p < 0.001) and GWE (87% [78% to 90%] to 90% [86% to 95%], p < 0.001). GCW was the only predictor of major adverse cardiovascular events (HR 0.99, 95% CI: 0.99 to 1.00, p = 0.04). Furthermore, GCW < 910 mmHg% was related to a high risk of major adverse cardiovascular events (HR 11.09, 95% CI: 1.45 to 98.94, p = 0.002, log-rank test p < 0.001). Another study by Wang et al.30 investigated a cohort of 508 patients (62.9 ± 15.8 years, 29.1% women) with LVEF ≤ 40%. The authors showed that GWI < 750 mmHg% was associated with significantly higher mortality and heart failure hospitalization and significantly higher all-cause death (HR 3.33, 95% CI: 2.31 to 4.80) than in patients with GWI ≥ 750 mmHg%. Regarding observations from these studies, MW analysis in patients with HFrEF may be valuable to identify CRT responders and provide prognostic information in this population.

The assessment of MW indices in heart failure with preserved ejection fraction (HFpEF) was reported in 2019 by Przewlocka-Kosmala et al.31 In the STRUCTURE (Spironolactone in Myocardial Dysfunction with Reduced Exercise Capacity) study, with 57 patients randomized to spironolactone and 57 to placebo, the authors measured MW indices at rest and immediately after exercise at baseline and at 6-month follow-up and reported GCW as a better determinant of exercise capacity than strain in HFpEF.

 Valve disease

Previous studies have also explored the clinical application of MW analysis in valve disease. Hubert et al.32 studied LV mechanics using MW analysis in 37 patients with heart failure and important functional mitral regurgitation who underwent percutaneous mitral valve repair, compared with 19 patients with functional mitral regurgitation in optimal clinical treatment. The authors reported that GCW significantly improved in both groups and demonstrated that GWI identifies patients with worse evolution (AUC = 0.882, p = 0.009), mainly patients with GWI < 482 mmHg%. Papadopoulos et al.33 investigated echocardiographic predictors of clinical response and LV reverse remodeling in 86 patients with severe functional mitral regurgitation and high surgical risk, including MW indices. The authors reported that baseline GWI and GCW were associated with a reduction in LV end-diastolic volume 1 year after the MitraClip intervention, and GCW was the only variable associated with a reduction in LV end-systolic volume. The MitraClip procedure was associated with significant improvement in GWI (p = 0.045) and GCW (p < 0.001). Yedidya et al.34 evaluated the prognostic impact of MW indices in functional mitral regurgitation. In 143 patients with functional mitral regurgitation, worse GWI and GCW values and better GWW and GWE values independently reflected worse prognosis in this population.

Jain et al.35 explored the relationship between severe aortic stenosis and MW analysis in a cohort of 35 patients undergoing transcatheter aortic valve replacement (TAVR). The authors evaluated MW indices in severe aortic stenosis with the addition of the mean aortic gradient to noninvasive systolic blood pressure. Based on this method, which showed a high correlation (r = 0.92), the authors demonstrated that GWI reduced between the pre-TAVR and post-TAVR periods (1856.2 mmHg% ± 704.6 versus 1534.8 mmHg% ± 385). The study by Fortuni et al.36 used the same calculation of MW indices in severe aortic stenosis that were shown to be independently associated with symptoms of heart failure. D’Andrea et al.37 recruited 115 asymptomatic patients with severe aortic insufficiency and 55 controls. GWE was significantly reduced in patients with aortic insufficiency compared to controls (87.1% ± 3.3% versus 94.4% ± 4.1%, p < 0.01), and strain and GWE were strong independent predictors of contractile reserve, suggesting early subclinical damage in this population. In a recent review by Muthukumar et al.38 on the association between malignant mitral valve prolapse and sudden cardiac death, the authors reported that patients with mitral valve prolapse and mitral annulus disjunction had higher MW regional index values in the posterolateral region of LV segments, suggesting the hypothesis that more work due to repeated traction causes greater energy demand and stress in these segments.

 Limitations and future directions

As with any new technology, MW needs to be disseminated for widespread knowledge of the protocol, with a learning curve and improved expertise. New software that has come to replace the invasive gold-standard method is the objective that researchers always seek to reduce the complications inherent to invasive methods, in this case, cardiac catheterization. For the time being, there is only one software product available from a single company.

The technical limitations are mostly related to the classic limitations of strain. For example, it requires an adequate acoustic window and frame rate, absence of tachycardia, and regular rhythm. Regarding blood pressure measurements, they need to be taken correctly, and patients with aortic stenosis or fixed LV outflow tract obstruction should be excluded, as noninvasively measured systolic pressure is not equivalent to invasive measurement. Blood pressure measurement needs to be adequate.

Moreover, MW is not useful for evaluating cases with important cardiac remodeling. It is a promising technique still under development.

 Conclusion

The development of new software associated with strain that presents good sensitivity and specificity, inserting only blood pressure measurements in a noninvasive manner will be important in the assessment of subclinical alterations that ejection fraction is not able to detect, assisting in the early treatment of several diseases that affect the myocardium, such as infiltrative, valvular, and ischemic diseases, thus changing their prognosis.

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Hiemstra YL, van der Bijl P, El Mahdiui M, Bax JJ, Delgado V, Marsan NA. Myocardial Work in Nonobstructive Hypertrophic Cardiomyopathy: Implications for Outcome. J Am Soc Echocardiogr. 2020;33(10):1201-8. doi: 10.1016/j.echo.2020.05.010. Hiemstra YL van der Bijl P El Mahdiui M Bax JJ Delgado V Marsan NA Myocardial Work in Nonobstructive Hypertrophic Cardiomyopathy: Implications for Outcome J Am Soc Echocardiogr 2020 33 10 1201 1208 10.1016/j.echo.2020.05.010 21. Clemmensen TS, Eiskjær H, Mikkelsen F, Granstam SO, Flachskampf FA, Sørensen J, et al. Left Ventricular Pressure-Strain-Derived Myocardial Work at Rest and during Exercise in Patients with Cardiac Amyloidosis. J Am Soc Echocardiogr. 2020;33(5):573-82. doi: 10.1016/j.echo.2019.11.018. Clemmensen TS Eiskjær H Mikkelsen F Granstam SO Flachskampf FA Sørensen J et al Left Ventricular Pressure-Strain-Derived Myocardial Work at Rest and during Exercise in Patients with Cardiac Amyloidosis J Am Soc Echocardiogr 2020 33 5 573 582 10.1016/j.echo.2019.11.018 22. Clemmensen TS, Eiskjær H, Ladefoged B, Mikkelsen F, Sørensen J, Granstam SO, et al. Prognostic Implications of Left Ventricular Myocardial Work Indices in Cardiac Amyloidosis. Eur Heart J Cardiovasc Imaging. 2021;22(6):695-704. doi: 10.1093/ehjci/jeaa097. Clemmensen TS Eiskjær H Ladefoged B Mikkelsen F Sørensen J Granstam SO et al Prognostic Implications of Left Ventricular Myocardial Work Indices in Cardiac Amyloidosis Eur Heart J Cardiovasc Imaging 2021 22 6 695 704 10.1093/ehjci/jeaa097 23. Russell K, Eriksen M, Aaberge L, Wilhelmsen N, Skulstad H, Gjesdal O, et al. Assessment of Wasted Myocardial Work: A Novel Method to Quantify Energy Loss Due To Uncoordinated Left Ventricular Contractions. Am J Physiol Heart Circ Physiol. 2013;305(7):H996-1003. doi: 10.1152/ajpheart.00191.2013. Russell K Eriksen M Aaberge L Wilhelmsen N Skulstad H Gjesdal O et al Assessment of Wasted Myocardial Work: A Novel Method to Quantify Energy Loss Due To Uncoordinated Left Ventricular Contractions Am J Physiol Heart Circ Physiol 2013 305 7 H996 1003 10.1152/ajpheart.00191.2013 24. Galli E, Leclercq C, Fournet M, Hubert A, Bernard A, Smiseth OA, et al. Value of Myocardial Work Estimation in the Prediction of Response to Cardiac Resynchronization Therapy. J Am Soc Echocardiogr. 2018;31(2):220-30. doi: 10.1016/j.echo.2017.10.009. Galli E Leclercq C Fournet M Hubert A Bernard A Smiseth OA et al Value of Myocardial Work Estimation in the Prediction of Response to Cardiac Resynchronization Therapy J Am Soc Echocardiogr 2018 31 2 220 230 10.1016/j.echo.2017.10.009 25. Galli E, Leclercq C, Hubert A, Bernard A, Smiseth OA, Mabo P, et al. Role of Myocardial Constructive Work in the Identification of Responders to CRT. Eur Heart J Cardiovasc Imaging. 2018;19(9):1010-18. doi: 10.1093/ehjci/jex191. Galli E Leclercq C Hubert A Bernard A Smiseth OA Mabo P et al Role of Myocardial Constructive Work in the Identification of Responders to CRT Eur Heart J Cardiovasc Imaging 2018 19 9 1010 1018 10.1093/ehjci/jex191 26. Cvijic M, Duchenne J, Ünlü S, Michalski B, Aarones M, Winter S, et al. Timing of Myocardial Shortening Determines Left Ventricular Regional Myocardial Work and Regional Remodelling in Hearts with Conduction Delays. Eur Heart J Cardiovasc Imaging. 2018;19(8):941-49. doi: 10.1093/ehjci/jex325. Cvijic M Duchenne J Ünlü S Michalski B Aarones M Winter S et al Timing of Myocardial Shortening Determines Left Ventricular Regional Myocardial Work and Regional Remodelling in Hearts with Conduction Delays Eur Heart J Cardiovasc Imaging 2018 19 8 941 949 10.1093/ehjci/jex325 27. Aalen JM, Donal E, Larsen CK, Duchenne J, Lederlin M, Cvijic M, et al. Imaging Predictors of Response to Cardiac Resynchronization Therapy: Left Ventricular Work Asymmetry by Echocardiography and Septal Viability by Cardiac Magnetic Resonance. Eur Heart J. 2020;41(39):3813-23. doi: 10.1093/eurheartj/ehaa603. Aalen JM Donal E Larsen CK Duchenne J Lederlin M Cvijic M et al Imaging Predictors of Response to Cardiac Resynchronization Therapy: Left Ventricular Work Asymmetry by Echocardiography and Septal Viability by Cardiac Magnetic Resonance Eur Heart J 2020 41 39 3813 3823 10.1093/eurheartj/ehaa603 28. van der Bijl P, Vo NM, Kostyukevich MV, Mertens B, Marsan NA, Delgado V, Bax JJ. Prognostic Implications of Global, Left Ventricular Myocardial Work Efficiency Before Cardiac Resynchronization Therapy. Eur Heart J Cardiovasc Imaging. 2019;20(12):1388-94. doi: 10.1093/ehjci/jez095. van der Bijl P Vo NM Kostyukevich MV Mertens B Marsan NA Delgado V Bax JJ Prognostic Implications of Global, Left Ventricular Myocardial Work Efficiency Before Cardiac Resynchronization Therapy Eur Heart J Cardiovasc Imaging 2019 20 12 1388 1394 10.1093/ehjci/jez095 29. Bouali Y, Donal E, Gallard A, Laurin C, Hubert A, Bidaut A, et al. Prognostic Usefulness of Myocardial Work in Patients with Heart Failure and Reduced Ejection Fraction Treated by Sacubitril/Valsartan. Am J Cardiol. 2020;125(12):1856-62. doi: 10.1016/j.amjcard.2020.03.031. Bouali Y Donal E Gallard A Laurin C Hubert A Bidaut A et al Prognostic Usefulness of Myocardial Work in Patients with Heart Failure and Reduced Ejection Fraction Treated by Sacubitril/Valsartan Am J Cardiol 2020 125 12 1856 1862 10.1016/j.amjcard.2020.03.031 30. Wang CL, Chan YH, Wu VC, Lee HF, Hsiao FC, Chu PH. Incremental Prognostic Value of Global Myocardial Work Over Ejection Fraction and Global Longitudinal Strain in Patients with Heart Failure and Reduced Ejection Fraction. Eur Heart J Cardiovasc Imaging. 2021;22(3):348-56. doi: 10.1093/ehjci/jeaa162. Wang CL Chan YH Wu VC Lee HF Hsiao FC Chu PH Incremental Prognostic Value of Global Myocardial Work Over Ejection Fraction and Global Longitudinal Strain in Patients with Heart Failure and Reduced Ejection Fraction Eur Heart J Cardiovasc Imaging 2021 22 3 348 356 10.1093/ehjci/jeaa162 31. Przewlocka-Kosmala M, Marwick TH, Mysiak A, Kosowski W, Kosmala W. Usefulness of Myocardial Work Measurement in the Assessment of Left Ventricular Systolic Reserve Response to Spironolactone in Heart Failure with Preserved Ejection Fraction. Eur Heart J Cardiovasc Imaging. 2019;20(10):1138-46. doi: 10.1093/ehjci/jez027. Przewlocka-Kosmala M Marwick TH Mysiak A Kosowski W Kosmala W Usefulness of Myocardial Work Measurement in the Assessment of Left Ventricular Systolic Reserve Response to Spironolactone in Heart Failure with Preserved Ejection Fraction Eur Heart J Cardiovasc Imaging 2019 20 10 1138 1146 10.1093/ehjci/jez027 32. Hubert A, Galli E, Leurent G, Corbineau H, Auriane B, Guillaume L, et al. Left Ventricular Function after Correction of Mitral Regurgitation: Impact of the Clipping Approach. Echocardiography. 2019;36(11):2010-8. doi: 10.1111/echo.14523. Hubert A Galli E Leurent G Corbineau H Auriane B Guillaume L et al Left Ventricular Function after Correction of Mitral Regurgitation: Impact of the Clipping Approach Echocardiography 2019 36 11 2010 2018 10.1111/echo.14523 33. Papadopoulos K, Ikonomidis I, Chrissoheris M, Chalapas A, Kourkoveli P, Parissis J, et al. MitraClip and Left Ventricular Reverse Remodelling: A Strain Imaging Study. ESC Heart Fail. 2020;7(4):1409-18. doi: 10.1002/ehf2.12750. Papadopoulos K Ikonomidis I Chrissoheris M Chalapas A Kourkoveli P Parissis J et al MitraClip and Left Ventricular Reverse Remodelling: A Strain Imaging Study ESC Heart Fail 2020 7 4 1409 1418 10.1002/ehf2.12750 34. Yedidya I, Lustosa RP, Fortuni F, van der Bijl P, Namazi F, Vo NM, et al. Prognostic Implications of Left Ventricular Myocardial Work Indices in Patients with Secondary Mitral Regurgitation. Circ Cardiovasc Imaging. 2021;14(9):e012142. doi: 10.1161/CIRCIMAGING.120.012142. Yedidya I Lustosa RP Fortuni F van der Bijl P Namazi F Vo NM et al Prognostic Implications of Left Ventricular Myocardial Work Indices in Patients with Secondary Mitral Regurgitation Circ Cardiovasc Imaging 2021 14 9 e012142 10.1161/CIRCIMAGING.120.012142 35. Jain R, Bajwa T, Roemer S, Huisheree H, Allaqaband SQ, Kroboth S, et al. Myocardial Work Assessment in Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement. Eur Heart J Cardiovasc Imaging. 2021;22(6):715-21. doi: 10.1093/ehjci/jeaa257. Jain R Bajwa T Roemer S Huisheree H Allaqaband SQ Kroboth S et al Myocardial Work Assessment in Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement Eur Heart J Cardiovasc Imaging 2021 22 6 715 721 10.1093/ehjci/jeaa257 36. Fortuni F, Butcher SC, van der Kley F, Lustosa RP, Karalis I, de Weger A, et al. Left Ventricular Myocardial Work in Patients with Severe Aortic Stenosis. J Am Soc Echocardiogr. 2021;34(3):257-66. doi: 10.1016/j.echo.2020.10.014. Fortuni F Butcher SC van der Kley F Lustosa RP Karalis I de Weger A et al Left Ventricular Myocardial Work in Patients with Severe Aortic Stenosis J Am Soc Echocardiogr 2021 34 3 257 266 10.1016/j.echo.2020.10.014 37. D’Andrea A, Sperlongano S, Formisano T, Tocci G, Cameli M, Tusa M, et al. Stress Echocardiography and Strain in Aortic Regurgitation (SESAR protocol): Left Ventricular Contractile Reserve and Myocardial Work in Asymptomatic Patients with Severe Aortic Regurgitation. Echocardiography. 2020;37(8):1213-21. doi: 10.1111/echo.14804. D’Andrea A Sperlongano S Formisano T Tocci G Cameli M Tusa M et al Stress Echocardiography and Strain in Aortic Regurgitation (SESAR protocol): Left Ventricular Contractile Reserve and Myocardial Work in Asymptomatic Patients with Severe Aortic Regurgitation Echocardiography 2020 37 8 1213 1221 10.1111/echo.14804 38. Muthukumar L, Jahangir A, Jan MF, Moreno ACP, Khandheria BK, Tajik AJ. Association between Malignant Mitral Valve Prolapse and Sudden Cardiac Death: A Review. JAMA Cardiol. 2020;5(9):1053-61. doi: 10.1001/jamacardio.2020.1412. Muthukumar L Jahangir A Jan MF Moreno ACP Khandheria BK Tajik AJ Association between Malignant Mitral Valve Prolapse and Sudden Cardiac Death: A Review JAMA Cardiol 2020 5 9 1053 1061 10.1001/jamacardio.2020.1412

Study Association

This study is not associated with any thesis or dissertation work.

Ethics Approval and Consent to Participate

This article does not contain any studies with human participants or animals performed by any of the authors.

Sources of Funding: There were no external funding sources for this study.

 10.36660/abcimg.20230052 Artigo de Revisão Como Eu Faço Myocardial Work : Por Que e Para Quem? 0000-0001-6421-3505 Lustosa Rodolfo de Paula Concepção e desenho da pesquisa redação do manuscrito e revisão crítica do manuscrito quanto ao conteúdo intelectual importante 1 2 3 0000-0002-2959-1874 Rabischoffsky Arnaldo Concepção e desenho da pesquisa redação do manuscrito e revisão crítica do manuscrito quanto ao conteúdo intelectual importante 2 4 0000-0002-0477-480X Gripp Eliza de Almeida Concepção e desenho da pesquisa redação do manuscrito e revisão crítica do manuscrito quanto ao conteúdo intelectual importante 4 5 Brazil Hospital Copastar, Rio de Janeiro, RJ – Brazil Brazil Hospital Américas Medical City, Rio de Janeiro, RJ – Brazil Brazil Hospital Quinta D’Or, Rio de Janeiro, RJ – Brazil Brazil Hospital Pró-Cardíaco, Rio de Janeiro, RJ – Brazil Brazil Hospital Universitário Antônio Pedro (UFF), Rio de Janeiro, RJ – Brazil Correspondência: Rodolfo de Paula Lustosa • Américas Medical City, Ecocardiografia. Av Jorge Curi, 550. CEP: 22275-001. Rio de Janeiro, RJ - Brasil E-mail: rodolfolustosarj@gmail.com

Potencial Conflito de Interesse

Declaro não haver conflito de interesses pertinentes.

Editor responsável pela revisão: Daniela do Carmo Rassi Frota

 Resumo

O surgimento de uma nova ferramenta não invasiva conhecida como miocardial work para avaliação da função ventricular que independe das condições de carga foi fundamental no avanço dos métodos de imagem vigentes como o strain miocárdico, considerada uma técnica sensível na detecção de disfunção subclínica, entretanto, ainda dependente das condições de carga, impossibilitando diferenciar alteração contrátil da interferência somente causada pelo aumento da pós-carga. Essa nova tecnologia incorporada ao strain miocárdico aumentará a sensibilidade do método.

 Introdução

O conceito das curvas de pressão-volume é amplamente usado na fisiologia cardiovascular e para avaliação da função cardíaca.1 - 3 Trabalhos experimentais demonstraram a possibilidade de avaliar a performance global dos ventrículos através de um índice de contratilidade que independe das condições de carga. Esse conceito ainda não se tornou “padrão ouro” na prática clínica e na pesquisa devido às técnicas invasivas ainda serem necessárias para determinação dessas curvas. Entretanto, os trabalhos demonstraram que a estimativa não invasiva dessas curvas é um forte preditor de eventos independente da fração de ejeção do ventrículo esquerdo (FEVE) como demonstrado no estudo de Spevack et al.4

Como eu faço

De acordo com o mesmo princípio das curvas de pressão-volume, o conceito da avaliação não invasiva do myocardial work (MW) foi publicado por Russell et al.5 em 2012. Segundo os autores, a determinação pelo ecodopplercardiograma da área da curva pressão- strain refletiria o MW e o consumo de oxigênio. Atualmente, o cálculo do MW pelo ecodopplercardiograma é realizado utilizando um software comercialmente disponível (EchoPac, GE sistemas médicos). Os índices de MW são estimados através da combinação da estimativa não invasiva do pico da pressão do ventrículo esquerdo (VE) utilizando as medidas da pressão arterial com o esfigmomanômetro (no qual se assume que o pico sistólico da pressão do VE é igual ao pico da pressão sistólica arterial) associadas aos dados ecocardiográficos de curvas do strain.

Após calcular o strain e introduzir os valores da pressão arterial obtidos pelo esfigmomanômetro, os tempos de abertura e fechamento das valvas aórtica e mitral são identificados pelo ecocardiograma no plano apical 3 câmaras. Uma curva pressão- strain do VE é então construída com os dados do strain de todo o ciclo cardíaco, de acordo com o tempo de duração do relaxamento e contração isovolumétrica, das fases de ejeção e enchimento definidas pelos tempos de abertura e fechamento das valvas aórtica e mitral e dos valores da pressão arterial.6

O trabalho do VE é calculado como um produto entre a taxa de encurtamento segmentar e a pressão instantânea do VE. Os seguintes índices são derivados da medida do trabalho cardíaco pelo ecocardiograma ( Figura Central ):

: Como Eu Faço <italic>Myocardial Work</italic> : Por Que e Para Quem? Cálculo do GWE do VE. Modelo de 17 segmentos mostrando os valores segmentares do GWE. Valores segmentares de GWE preservados são apresentados em verde e expressos em %. Os valores do GWI, GCW, GWW, GWE e pressão arterial do paciente são mostrados em branco. GCW: global constructive work; GWE: global work efficiency; GWI: global work index; GWW: global wasted work (Fonte: Autor).

Global work index (GWI): trabalho total calculado do fechamento da valva mitral até a abertura da valva mitral representando a área da curva fornecida pelo software (valor em mmHg%);

Global constructive work (GCW): trabalho realizado por um segmento durante o encurtamento na sístole adicionado ao trabalho negativo durante o alongamento na diástole que representa o trabalho que contribui para a contratilidade miocárdica (valor em mmHg%);

Global wasted work (GWW): trabalho negativo realizado por um segmento durante seu alongamento na sístole adicionado ao trabalho realizado durante o encurtamento na diástole que representa o trabalho que não contribui para a contratilidade miocárdica (valor em mmHg%);

Global work efficiency (GWE): relação do GCW dividido pela soma de GCW e GWW, representando a medida de performance do VE (valor em %).

As médias dos valores de normalidade reportadas7 são de 2010 mmHg% (intervalo de confiança [IC] 95%: 1907 a 2113 mmHg%) e 2278 mmHg% (IC 95%: 2186 a 2369 mmHg%) para GWI e GCW, respectivamente. A média para GWW é de 80 mmHg% (IC 95%: 73 a 87 mmHg%) e para GWE é de 96% (IC 95%: 96% a 96%). A diferença entre homens e mulheres significativamente contribui para as variações de normalidade para GWI, GWW e GWE.

 Aplicabilidade Doença isquêmica cardíaca

A utilização do MW na doença arterial coronariana pode ser dividida no contexto das síndromes coronarianas agudas e da doença arterial coronariana crônica. Além disso, não somente os valores globais são relevantes, como também os valores regionais derivados do software. Em pacientes com infarto agudo do miocárdio com supradesnível do segmento ST (IAMCSST), o estudo de El Mahdiui et al.8 evidenciou que GWE foi reduzido em pacientes com insuficiência cardíaca com fração de ejeção reduzida (ICFEr) pós IAMCSST em comparação com indivíduos saudáveis e aqueles com fatores de risco para doenças cardiovasculares. Estudo de Lustosa et al.9 demonstrou em uma coorte de 600 pacientes pós IAMCSST que os índices de trabalho cardíaco eram reduzidos 3 meses após o evento índice em pacientes que apresentaram remodelamento ventricular. O mesmo autor demonstrou que valores reduzidos de GWE (< 86%) medidos pelo ecodopplercardiograma transtorácico nas primeiras 48 horas de admissão do IAMCSST estaria associado com pior prognóstico.10 O trabalho de Meimoun et al.11 demonstrou que, em pacientes com IAMCSST anteriormente tratados com intervenção coronariana percutânea, GCW foi um fator independente para recuperação global e segmentar do VE e estava significativamente reduzido em pacientes que apresentaram complicações intra-hospitalares.

No contexto de avaliação regional do MW , o estudo de Boe et al.12 demonstrou que a presença de valores regionais reduzidos de GWI poderiam identificar oclusão coronariana em pacientes com infarto agudo do miocárdio sem supradesnível do segmento ST (IAMSSST). Estudo de Lustosa et al.,13 através de valores regionais de GWI, demonstrou que valores regionais reduzidos de GWI no território da artéria culpada foram independentemente associados a remodelamento cardíaco precoce.

O MW também foi estudado na doença arterial coronariana crônica. Estudo de Edwards et al.14 avaliou 115 pacientes com FEVE normal encaminhados para angiografia coronariana devido a diferentes indicações e demonstrou que um valor inferior a 1810 mmHg% para o GWI foi um preditor para doença arterial coronariana significativa (definido por estenose acima de 70%) com uma sensibilidade de 92% e especificidade de 51%. Estudo de Borrie et al.15 demonstrou que os índices de MW podem ser utilizados na ecocardiografia com stress para identificação de isquemia miocárdica.

 Cardiomiopatias

O principal papel da análise do MW na prática clínica para avaliação de pacientes com cardiomiopatias tem foco em pacientes com cardiomiopatia dilatada (CMD), cardiomiopatia hipertrófica (CMH) e amiloidose cardíaca (AC). No trabalho de Chan et al.16 foi observada a diferença entre os índices de MW em pacientes com hipertensão e CMD (19 pacientes não-isquêmicos e 10 pacientes isquêmicos). Os autores reportaram que GWI, GCW e GWE estavam significativamente reduzidos e GWW estava significativamente aumentado em pacientes com CMD em comparação com o grupo controle. O estudo de Schrub et al.17 investigou a relação entre a análise do MW e a tolerância ao exercício em 51 pacientes com CMD submetidos a um teste de exercício cardiopulmonar para avaliar o desempenho do exercício e relatou que, em pacientes com CMD e dissincronismo intraventricular, a eficiência do trabalho septal foi o único preditor de capacidade de exercício na análise multivariada (β = 0,68, p = 0,03). Estudo de Cui et al.18 comparou os índices de MW em 30 pacientes com CMD e 30 pacientes saudáveis e observou valores significativamente reduzidos dos índices de MW no grupo CMD em relação ao grupo controle (p < 0,05).

Em 2019, Galli et al.19 estudaram 82 pacientes com CMH não obstrutiva submetidos à avaliação de análise de MW. Os pacientes também realizaram ressonância magnética cardíaca para estimar a fibrose do VE com realce tardio pelo gadolínio. Os autores relataram que o GCW é significativamente reduzido em CMH e FEVE normal e um valor de corte de 1623 mmHg% demonstrou sensibilidade de 82% e especificidade de 67% para prever fibrose do VE nessa população (área sob a curva [AUC] 0,80, IC 95%: 0,66 a 0,93, p < 0,001). Trabalho de Hiemstra et al.20 relatou o papel prognóstico da análise de MW em 110 pacientes com CMH não obstrutiva. Os pacientes com GCW > 1730 mmHg% apresentaram sobrevida melhor em comparação àqueles com GCW < 1730 mmHg% (log-rank 11,2, p = 0,001).

O valor da aplicação clínica dos índices MW em pacientes com AC foi relatado por Clemmensen et al.21 O objetivo dos autores foi caracterizar o MW em repouso e no pico durante o exercício em pacientes com AC. Observaram que pacientes com AC apresentam valores de índices de MW significativamente reduzidos e essa diferença foi mais evidente com o exercício em comparação com indivíduos saudáveis. Em outro estudo, as implicações prognósticas da análise de MW foram demonstradas em 100 pacientes com AC.22 Pacientes com GWI < 1043 mmHg% apresentaram maior número de eventos do que pacientes com GWI > 1043 mmHg% (hazard ratio [HR] 2,3, IC 95%: 1,2 a 4,3, p = 0,01). Além disso, pacientes com GWI < 1039 mmHg% apresentaram maior risco de mortalidade por todas as causas do que pacientes com GWI > 1039 mmHg% (HR 2,6, IC 95%: 1,2 a 5,5, p < 0,05).

 ICFEr e resposta à terapia de ressincronização cardíaca (TRC)

Os primeiros relatos na prática clínica sobre a aplicação de MW em pacientes com ICFEr foram observados em 2013. Em um estudo experimental, Russell et al.23 avaliaram o WW ratio (WWR) em 6 cães anestesiados com bloqueio de ramo esquerdo (BRE) e 28 pacientes com cardiomiopatia, incluindo pacientes com BRE e TRC. O estudo demonstrou uma forte correlação entre WWR estimado de forma invasiva e não invasiva em cães (r = 0,94) e pacientes (r = 0,96) com valores mais elevados de WWR global em pacientes com BRE. O trabalho de Galli et al.24 estimou o GCW e GWW em 97 pacientes antes da TRC e no seguimento de 6 meses. Os autores mostraram que a adição de GCW > 1057 mmHg% e GWW > 384 mmHg% a um modelo basal aumentou significativamente o poder do modelo para identificar respondedores de TRC e relataram boa especificidade (100%) e valor preditivo positivo (100%), mas baixa sensibilidade (22%), valor preditivo negativo (41%) e acurácia (49%). Em outro estudo25 os autores mostraram também em 97 pacientes submetidos a implante de TRC que um GCW > 1057 mmHg% (odds ratio [OR] 14,69, p = 0,005) e septal flash (OR 8,05, p = 0,004) foram os únicos preditores de resposta à TRC. O estudo de Cvijic et al.26 calculou o trabalho segmentar do miocárdio em 26 pacientes com ritmo sinusal e cardiomiopatia não isquêmica. Antes da TRC, o trabalho se distribuía de modo não uniforme com o trabalho reduzido em parede septal e anteroseptal e trabalho aumentado em paredes lateral e posterior (p < 0,001). Os autores mostraram que após TRC a distribuição do trabalho segmentar foi uniforme. A assimetria de MW entre os segmentos septais e a parede lateral também foi observada em um estudo prospectivo multicêntrico com 200 pacientes.27 Os autores mostraram que a diferença de trabalho entre o septo e a parede lateral previu a resposta da TRC com a AUC de 0,77 (IC 95%: 0,70 a 0,84) e, combinando com a viabilidade septal pela ressonância magnética cardíaca, a AUC aumentou para 0,88 (IC 95%: 0,81 a 0,95). A importância prognóstica do cálculo do MW em pacientes com insuficiência cardíaca foi demonstrada por van der Bijl et al.28 em uma coorte de pacientes com indicações classe I para TRC. Os autores demonstraram que pacientes com eficiência energética menor (GWE < 75%) antes da TRC demonstraram menor taxa de eventos que pacientes com uma eficiência energética maior (GWE > 75%). Trabalho de Bouali et al.29 investigou o efeito do tratamento com sacubitril/valsartan nos índices de MW em 79 pacientes com ICFEr e relatou que o tratamento aumentou significativamente o GCW (1023 ± 449 mmHg% para 1424 ± 484 mmHg%, p < 0,001) e GWE (87% [78% a 90%] a 90% [86% a 95%], p < 0,001). O GCW foi o único preditor de eventos cardiovasculares adversos maiores (MACE) (HR 0,99, IC 95%: 0,99 a 1,00, p = 0,04). Além disso, GCW < 910 mmHg% foi relacionado a um alto risco de MACE (HR 11,09, IC 95%: 1,45 a 98,94, p = 0,002, teste log-rank p < 0,001). Em outro estudo de Wang et al.,30 foi investigada uma coorte de 508 pacientes (62.9 ± 15.8 anos, 29.1% mulheres) com FEVE ≤ 40%. Os autores mostraram que GWI < 750 mmHg% foi associado à mortalidade e hospitalização por insuficiência cardíaca significativamente maior e à morte por todas as causas significativamente maior (HR 3,33, IC 95%: 2,31 a 4,80) do que em pacientes com GWI ≥ 750 mmHg%. Em relação às observações desses estudos, a análise de MW em pacientes com ICFEr pode ser valiosa para identificar respondedores à TRC e fornecer informações prognósticas nessa população.

A avaliação dos índices de MW na insuficiência cardíaca com fração de ejeção preservada (ICFEp) foi relatada em 2019 por Przewlocka-Kosmala et al.31 No estudo STRUCTURE (Spironolactone in myocardial dysfunction with reduced exercise capacity), com 57 pacientes randomizados para espironolactona e 57 para placebo, os autores mediram os índices de MW em repouso e imediatamente após o exercício no basal e aos 6 meses de acompanhamento e relataram GCW como um melhor determinante da capacidade de exercício do que o strain na ICFEp.

 Doença valvar

A aplicação clínica da análise MW na doença valvar também foi explorada em estudos anteriores. O estudo de Hubert et al.32 estudou a mecânica do VE com análise de MW em 37 pacientes com insuficiência cardíaca e insuficiência mitral funcional importante submetidos a reparo percutâneo da valva mitral e comparou com 19 pacientes com insuficiência mitral funcional em tratamento clínico otimizado. Os autores relataram que o GCW melhorou significativamente em ambos os grupos e demonstraram que o GWI identifica pacientes com pior evolução (AUC = 0,882, p = 0,009), principalmente pacientes com GWI < 482 mmHg%. Papadopoulos et al.33 investigaram os preditores ecocardiográficos de resposta clínica e remodelamento reverso do VE em 86 pacientes com insuficiência mitral funcional grave e alto risco cirúrgico, incluindo índices de MW. Os autores relataram que GWI e GCW basais foram associados a uma redução do volume diastólico final do VE um ano após a intervenção MitraClip e o GCW foi a única variável associada a uma redução do volume sistólico final do VE. O procedimento MitraClip foi associado a melhora significativa em GWI (p = 0,045) e GCW (p< 0,001). O trabalho de Yedidya et al.34 avaliou o impacto prognóstico dos índices de MW na insuficiência mitral funcional. Em 143 pacientes com insuficiência mitral funcional, os piores valores de GWI e GCW e os melhores valores de GWW e GWE refletiram independentemente um pior prognóstico nessa população.

A relação entre estenose aórtica grave e análise MW foi explorada por Jain et al.35 em uma coorte de 35 pacientes submetidos à troca percutânea da valva aórtica (TAVR). Os autores se propuseram a avaliar os índices de MW na estenose aórtica grave com a adição do gradiente aórtico médio à pressão arterial sistólica não invasiva. Com base nesse método, que apresentou alta correlação (r = 0,92), os autores demonstraram que o GWI reduziu de pré-TAVR para pós-TAVR (1856,2 mmHg% ± 704,6 versus 1534,8 mmHg% ± 385). O trabalho de Fortuni et al.36 utilizou o mesmo cálculo dos índices de MW na estenose aórtica grave que se mostraram independentemente associados a sintomas de insuficiência cardíaca. D’Andrea et al.37 recrutaram 115 pacientes assintomáticos com insuficiência aórtica grave e 55 controles. O GWE foi significativamente reduzido em pacientes com insuficiência aórtica em comparação com controles (87,1% ± 3,3% versus 94,4% ± 4,1%, p < 0,01) e o strain e GWE foram fortes preditores independentes da reserva contrátil, sugerindo dano subclínico precoce nessa população. Em recente revisão de Muthukumar et al.38 sobre a associação entre prolapso maligno da valva mitral e morte súbita cardíaca, os autores relataram que pacientes com prolapso da valva mitral e disjunção do anel mitral apresentaram valores mais elevados de índice regional de MW na região póstero-lateral de segmentos do VE, sugerindo a hipótese de maior trabalho devido à tração repetida causar maior demanda energética e estresse nestes segmentos.

 Limitações e direções futuras

Assim como qualquer nova tecnologia, precisa ser difundida para amplo conhecimento do protocolo, com curva de aprendizado e melhoria da expertise. Um novo software que veio substituir o método ouro invasivo é o objetivo que os pesquisadores sempre buscam para reduzir as complicações inerentes aos métodos invasivos, como nesse caso o cateterismo cardíaco. Por enquanto, somente existe um software disponível de uma única empresa.

As limitações técnicas estão mais relacionadas àquelas clássicas do strain . Por exemplo, precisa de janela acústica e frame rate adequados, ausência de taquicardia e ritmo regular. Em relação à medida da pressão arterial, precisa ser aferida de forma correta e pacientes com estenose aórtica ou com obstrução fixa da via de saída do VE são excluídos, pois a pressão sistólica aferida de forma não invasiva não equivale à medida invasiva. A medida da pressão arterial necessita ser adequada.

Além disso, o MW não serve para avaliar casos que apresentam importante remodelamento cardíaco. É uma técnica promissora ainda em desenvolvimento.

 Conclusão

O desenvolvimento de um novo software associado ao strain que apresenta boa sensibilidade e especificidade, inserindo somente as medidas de pressão arterial de forma não invasiva será importante na avaliação das alterações subclínicas que a fração de ejeção não é capaz de detectar, auxiliando no tratamento precoce de diversas doenças que acometem o miocárdio, como doenças infiltrativas, valvares e isquêmicas, mudando o prognóstico.

Vinculação Acadêmica

Não há vinculação deste estudo a programas de pós-graduação.

Aprovação Ética e Consentimento Informado

Este artigo não contém estudos com humanos ou animais realizados por nenhum dos autores.

Fontes de Financiamento: O presente estudo não teve fontes de financiamento externas.