Dipyridamole – ABC CARDIOL

ABCIC

Case Report

Acute myocardial infarction after myocardial scintigraphy with dipyridamole

Rafael Alessandro Ferreira Gomes et al. Isabelle Conceição Albuquerque Machado Moreira Otávio Guilherme de Moraes Cardoso Alexandre Gomes de Souza Melo Aluísio Roberto Andrade Macêdo Junior

[…]

Read Full Article

ABC

Review Article

Evaluation of Myocardial Perfusion by Computed Tomography – Principles, Technical Background and Recommendations

Tiago Augusto Magalhães et al. Roberto Caldeira Cury Rodrigo Julio Cerci José Rodrigues Parga Filho … Ilan Gottlieb Marcelo Souto Nacif Ibraim Masciarelli Pinto Carlos Eduardo Rochitte Fabio Vilas-Boas Paulo R. Schvartzman

Abstract

Coronary computed tomography angiography (CCTA) has gained a prominent role in the evaluation of coronary artery disease. However, its anatomical nature does not allow the evaluation of the functional repercussion of coronary obstructions. It has been made possible to evaluate Myocardial computed tomography perfusion (Myocardial CTP) recently, based on myocardial contrast changes related to coronary stenoses. Several studies have validated this technique against the anatomical reference method (cardiac catheterization) and other functional methods, including myocardial perfusion scintigraphy and fractional flow reserve. The Myocardial CTP is performed in conjunction with the CCTA, a combined analysis of anatomy and function. The stress phase (with assessment of myocardial perfusion) can be performed before or after the resting phase (assessment of resting perfusion and coronary arteries), and different acquisition parameters are proposed according to the protocol and type of equipment used. Stressors used are based on coronary vasodilation (e.g. dipyridamole, adenosine). Image interpretation, similar to other perfusion assessment methods, is based on the identification and quantification of myocardial perfusion defects. The integration of both perfusion and anatomical findings is fundamental for the examination interpretation algorithm, allowing to define if the stenoses identified are hemodynamically significant and may be related to myocardial ischemia.

Read Full Article

IJCS

Original Article

Rescue Therapy with Nifurtimox and Dipyridamole for Severe Acute Chagas Myocarditis with Congestive Heart Failure in NMRI Albino Mice

Daniela Yustiz Aparicio et al. María González-Hernández Greybis Hernández-Forero María Guédez-Ortiz … Sonia Santeliz Loredana Goncalves Rafael Bonfante Cabarcas

Abstract

Background:

Chagas disease is a global health problem; therefore, the development of new therapeutic protocols is necessary. Our group recently demonstrated that nifurtimox associated with dipyridamole has curative effects in mice with acute Chagas disease. In this study, we assess the effect of this therapeutic protocol in chagasic mice with heart failure.

Objective:

To evaluate whether nifurtimox and dipyridamole are useful to rescue mice with severe acute chagasic myocarditis with heart failure.

Methods:

42 mice with acute chagasic myocarditis and congestive heart failure were divided into three groups: control chagas (n = 11), Nif-Dip treated with nifurtimox and dipyridamole (n = 14) and Nif-Dip-heart failure treated with nifurtimox and dipyridamole associated with digoxin, furosemide, and captopril (n = 17). Nifurtimox and dipyridamole doses were 40 and 30 mg/kg/day, respectively, for 6 weeks. Mice underwent clinical, electrocardiographic, hemoparasitological and histopathological assessments.

Results:

Lower mortality in Nif-Dip (28.57%; n = 4) compared to control chagas (54.54%; n = 6) and Nif-Dip-heart failure (52.9%; n = 9) was observed. Clinically, nifurtimox and dipyridamole-treated mice increased body weight and improved heart failure without splenomegaly. In these groups, parasitemia and tissue parasites were eradicated; fibrosis, myocytolysis, inflammatory cell infiltrate and mast cells decreased. Repolarization disorders, prolonged QRS and QT intervals, increase of S wave amplitude and atrioventricular dissociation were reversed by the treatment.

Conclusion:

Nifurtimox with dipyridamole can rescue NMRI mice from severe acute chagas disease, as nifurtimox showed trypanocidal activity and dipyridamole potentiated its effect. Dipyridamole would be useful in chagasic heart failure.

Read Full Article

ABC

Original Article

Dipyridamole stress myocardial perfusion by computed tomography in patients with left bundle branch block

Estêvan Vieira Cabeda et al. Andréa Maria Gomes Falcão José Soares Jr. Carlos Eduardo Rochitte … César Higa Nomura Luiz Francisco Rodrigues Ávila José Rodrigues Parga

Abstract

Background:

Functional tests have limited accuracy for identifying myocardial ischemia in patients with left bundle branch block (LBBB).

Objective:

To assess the diagnostic accuracy of dipyridamole-stress myocardial computed tomography perfusion (CTP) by 320-detector CT in patients with LBBB using invasive quantitative coronary angiography (QCA) (stenosis ≥ 70%) as reference; to investigate the advantage of adding CTP to coronary computed tomography angiography (CTA) and compare the results with those of single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy.

Methods:

Thirty patients with LBBB who had undergone SPECT for the investigation of coronary artery disease were referred for stress tomography. Independent examiners performed per-patient and per-coronary territory assessments. All patients gave written informed consent to participate in the study that was approved by the institution’s ethics committee.

Results:

The patients’ mean age was 62 ± 10 years. The mean dose of radiation for the tomography protocol was 9.3 ± 4.6 mSv. With regard to CTP, the per-patient values for sensitivity, specificity, positive and negative predictive values, and accuracy were 86%, 81%, 80%, 87%, and 83%, respectively (p = 0.001). The per-territory values were 63%, 86%, 65%, 84%, and 79%, respectively (p < 0.001). In both analyses, the addition of CTP to CTA achieved higher diagnostic accuracy for detecting myocardial ischemia than SPECT (p < 0.001).

Conclusion:

The use of the stress tomography protocol is feasible and has good diagnostic accuracy for assessing myocardial ischemia in patients with LBBB.

Read Full Article

ABC

Artigo Original

Diagnostic value of myocardial radionuclide imaging in patients with multivessel coronary disease

Maria Eduarda Menezes de Siqueira et al. Erly Medeiros Vieira Segundo Neto Juliana Fernandes Kelendjian Paola Emanuela Pogio Smanio

BACKGROUND: Myocardial perfusion radionuclide imaging (MPRI) is a noninvasive method extremely useful for evaluating ischemia in patients with coronary disease. However, the idea that this method would not be effective for patients with multivessel coronary disease is still entertained. OBJECTIVE: Assess the value of MPRI with gated-SPECT for tracing pharmacological stress-induced ischemia in patients with multivessel obstructive coronary disease. METHODS: We evaluated 68 patients with multivessel obstructive coronary disease applying coronary angiography for performing MPRI under pharmacologic stress with dipyridamole. The tests were analyzed by two nuclear medicine physicians without prior knowledge of the result of the coronary angiography. RESULTS: Gated-SPECT revealed that, out of the patients, 64 (92.8%) showed images of perfusion abnormalities and 4 (7.2%) showed normal perfusion, given that three of the latter showed functional changes. CONCLUSION: MPRI has shown high value for identifying patients with multivessel coronary disease, since most patients had perfusion abnormalities indicative of ischemia.

Read Full Article

ABC

Artigo Original

Quantification of left ventricular dilatation in myocardial perfusion scintigraphy

Mauren B. Azambuja Gonzalez et al. Roberto Alves Azambuja Luiz Carlos Bodanese

BACKGROUND: The rate of transient dilatation can be determined by exercise testing or pharmacological stress test. It is unknown whether the type of stress has an impact on average transient dilatation index values. OBJECTIVE: To compare average transient dilation index values in 99mTc-sestamibi scintigraphy in patients undergoing treadmill stress test, versus dipyridamole stress test. The secondary purpose was to evaluate the impact on the average index value by demographic characteristics, risk factors for coronary artery disease and severity of ischemia. METHODS: The cross-sectional study included 200 patients between 40 and 70 years old, with or without risk factors for ischemic heart disease, with or without a previous diagnosis of ischemic heart disease. The separation between groups was sequential. The software 4D-MSPECT calculated the transient dilatation index and provided a scoring system for perfusion analysis. RESULTS: The average transient dilation index value of the group undergoing exercise stress test was 1.06 (±0.23). For the group undergoing the dipyridamole stress test, it was 1.10 (±0.22); (p = 0.200). There was no association between the type of stress and the average transient dilatation index values. An association was found between the average index values and age only for those patients from the exercise test group (p = 0.009). CONCLUSION: The results of our study demonstrate that the transient dilation index does not differ when patients undergo exercise stress test on a treadmill or pharmacological stress by dipyridamole.

Read Full Article

ABC

Artigo Original

Prognostic value of dipyridamole stress echocardiography in women

Maria Celita de Almeida et al. Brivaldo Markman Filho

BACKGROUND: Stress echocardiography is an important diagnostic and prognostic tool in ischemic heart disease. OBJECTIVE: To evaluate the role of dipyridamole stress echocardiography (DSE) in the investigation of myocardial ischemia in women and its ability to predict combined events (cardiovascular death, acute myocardial infarction [AMI], unstable angina, coronary artery bypass grafting [surgery or percutaneous intervention] at an average follow-up of 16 months. METHODS: A prospective study using the protocol of dipyridamole at 0.84 mg in 10 minutes, associated with atropine (0.25 mg/min up to 1.0 mg). RESULTS: This study evaluated 147 women. DSE was positive in 14 patients (9.5%), negative in 128 (87.1%) and inconclusive in 5 (3.4%). Events occurred in 8 patients, 7 had positive DSE. The other 138 did not present any events. Our of these, 128 had negative DSE. The sensitivity, specificity, accuracy, the positive and negative predictive values of the test before the events were respectively: 83%, 95%, 94%, 42% and 99%. The event-free survival for patients with negative DSE was 99.2% compared with 58% for positive DSE (p < 0.001). Univariate analysis identified the DSE result, basal electrocardiogram (ECG), LV ejection fraction, dyslipidemia, wall motion score index at rest and peak, history of AMI, coronary artery bypass grafting, as prognostic predictors related to outcomes. The results of DSE and ECG remained significantly associated with outcomes in the multivariate analysis (p < 0.001). CONCLUSION: The baseline ECG and positive DSE were independent variables for the occurrence of outcomes. The DSE showed excellent negative predictive value, confirming its usefulness in evaluating prognosis in such patients.

Read Full Article