William Azem Chalela

Noninvasive diagnosis of allograft vascular disease after heart transplantation

OBJECTIVE To determine the predictive values of noninvasive tests for the detection of allograft vascular disease. METHODS We studied 39 patients with mean ages of 48+/-13 years and a follow-up period of 86+/-13 months. The diagnosis of allograft vascular disease was made by cine-coronary arteriography, and it was considered as positive if lesions existed that caused > or =50% obstruction of the lumen. Patients underwent 24h Holter monitoring, thallium scintigraphy, a treadmill stress test, and dobutamine stress echocardiography. Sensitivity, specificity, and positive and negative predictive values were determined in percentages for each method, as compared with the cine-coronary arteriography results. RESULTS Allograft vascular disease was found in 15 (38%) patients. The Holter test showed 15.4% sensitivity, 95.5% specificity. For the treadmill stress test, sensitivity was 10%, specificity was 100%. When thallium scintigraphy was used, sensitivity was 40%, specificity 95.8%. On echocardiography with dobutamine, we found a 63.6% sensitivity, 91.3% specificity. When the dobutamine echocardiogram was associated with scintigraphy, sensitivity was 71.4%, specificity was 87%. CONCLUSION In this group of patients, the combination of two noninvasive methods (dobutamine echocardiography and thallium scintigraphy) may be a good alternative for the detection of allograft vascular disease in asymptomatic patients with normal ventricular function.

Estudo comparativo entre os efeitos terapêuticos da revascularizacão cirúrgica do miocárdio e angioplastia coronária em situacões isquêmicas equivalentes: análise através da cintilografia do miocárdio com 99mTc-Sestamibi

OBJECTIVE To assess the myocardial ischemic load to previous and after myocardial revascularization. METHODS Ninety-six randomized patients, carriers of multivessel coronary artery disease, stable angina, preserved left ventricular function, and exercise-induced myocardial ischemia treated with revascularization (SMR) or coronary angioplasty (TCA). Myocardial scintigraphy with 99mTc-Sestamibi was performed prior to and 6 months after myocardial revascularization. RESULTS The SMR determined a significant greater index of complete revascularization (p=0.001), an increase in the number of maximum ergometric tests (p=0.001) and reduction in the number of positive ergometric tests with exercise angina (p=0.018). Both procedures provided an important improvement in the functional class of angina (p=0.001), an increase in the average value of double peak product (p=0.009), and the time of exercise tolerance (p<0.001), besides the reduction in the average value of the summed of exercise score (p<0.001) and the difference of the summed of scores (p<0.001) in both groups. CONCLUSION TCA and SMR did not differ significantly concerning the reduction of myocardial ischemic load 6 months after the procedure. The myocardial revascularization was more complete with the SMR than the TCA, but it did not represent a significant factor for the reduction myocardial ischemic load.

Treadmill exercise testing of asymptomatic men and women without evidence of heart disease

The aim of this study was to test the hypothesis of differences in performance including differences in ST-T wave changes between healthy men and women submitted to an exercise stress test. Two hundred (45.4%) men and 241 (54.6%) women (mean age: 38.7 +/- 11.0 years) were submitted to an exercise stress test. Physiologic and electrocardiographic variables were compared by the Student t-test and the chi-square test. To test the hypothesis of differences in ST-segment changes, data were ranked with functional models based on weighted least squares. To evaluate the influence of gender and age on the diagnosis of ST-segment abnormality, a logistic model was adjusted; P < 0.05 was considered to be significant. Rate-pressure product, duration of exercise and estimated functional capacity were higher in men (P < 0.05). Sixteen (6.7%) women and 9 (4.5%) men demonstrated ST-segment upslope >or=0.15 mV or downslope >or=0.10 mV; the difference was not statistically significant. Age increase of one year added 4% to the chance of upsloping of segment ST >or=0.15 mV or downsloping of segment ST >or=0.1 mV (P = 0.03; risk ratio = 1.040, 95% confidence interval (CI) = 1.002-1.080). Heart rate recovery was higher in women (P < 0.05). The chance of women showing an increase of systolic blood pressure <or=30 mmHg was 85% higher (P = 0.01; risk ratio = 1.85, 95%CI = 1.1-3.05). No significant difference in the frequency of ST-T wave changes was observed between men and women. Other differences may be related to different physical conditioning.

Exercise stress testing before and after successful multivessel percutaneous transluminal coronary angioplasty

Controversy exists regarding the diagnostic accuracy, optimal technique, and timing of exercise testing after percutaneous coronary intervention. The objectives of the present study were to analyze variables and the power of exercise testing to predict restenosis or a new lesion, 6 months after the procedure. Eight-four coronary multi-artery diseased patients with preserved ventricular function were studied (66 males, mean age of all patients: 59 +/- 10 years). All underwent coronary angiography and exercise testing with the Bruce protocol, before and 6 months after percutaneous coronary intervention. The following parameters were measured: heart rate, blood pressure, rate-pressure product (heart rate x systolic blood pressure), presence of angina, maximal ST-segment depression, and exercise duration. On average, 2.33 lesions/patient were treated and restenosis or progression of disease occurred in 46 (55%) patients. Significant increases in systolic blood pressure (P = 0.022), rate-pressure product (P = 0.045) and exercise duration (P = 0.003) were detected after the procedure. Twenty-seven (32%) patients presented angina during the exercise test before the procedure and 16 (19%) after the procedure. The exercise test for the detection of restenosis or new lesion presented 61% sensitivity, 63% specificity, 62% accuracy, and 67 and 57% positive and negative predictive values, respectively. In patients without restenosis, the exercise duration after percutaneous coronary intervention was significantly longer (460 +/- 154 vs 381 +/- 145 s, P = 0.008). Only the exercise duration permitted us to identify patients with and without restenosis or a new lesion.

Avaliação prognóstica da doença coronária estável através de um novo escore

FUNDAMENTO: A necessidade de melhorar a acuracia do teste de esforco, determinou o desenvolvimento de escores, cuja aplicabilidade ja foi amplamente reconhecida. OBJETIVO: Avaliacao prognostica do coronariopata estavel atraves de um novo escore simplificado. METODOS: Um novo escore foi aplicado em 372 coronariopatas multiarteriais e funcao ventricular preservada, 71,8% homens, idade media 59,5 (± 9,07) anos, randomizados para angioplastia, revascularizacao cirurgica e tratamento clinico, acompanhados por 5 anos. Obito cardiovascular foi o desfecho primario. Infarto do miocardio nao-fatal, obito e re-intervencao formaram o desfecho combinado secundario. O escore baseou-se numa equacao previamente validada resultante da soma de 1 ponto para: sexo masculino, historia de infarto, angina, diabete, uso de insulina e ainda 1 ponto para cada decada de vida a partir dos 40 anos. Teste positivo adicionou 1 ponto. RESULTADOS: Ocorreram 36 obitos (10 no grupo angioplastia, 15 no grupo revascularizacao e 11 no grupo clinico), p = 0,61. Observou-se 93 eventos combinados: 37 no grupo angioplastia, 23 no grupo revascularizacao e 33 no grupo clinico (p = 0,058). 247 pacientes apresentaram escore clinico > 5 pontos e 216 > 6 pontos. O valor de corte > 5 ou > 6 pontos identificou maior risco, com p = 0,015 e p = 0,012, respectivamente. A curva de sobrevida mostrou uma incidencia de obito apos a randomizacao diferente naqueles com escore > 6 pontos (p = 0,07), e uma incidencia de eventos combinados diferente entre pacientes com escore 6 pontos (p = 0,02). CONCLUSAO: O novo escore demonstrou consistencia na avaliacao prognostica do coronariopata estavel multiarterial.BACKGROUND The need to improve the exercise testing accuracy, pushed the development of scores, whose applicability was already broadly recognized. OBJECTIVE Prognostic evaluation of stable coronary disease through a new simplified score. METHODS A new score was applied in 372 multivessel coronary patients with preserved ventricular function, 71.8% male, age: 59.5 (± 9.07) years old, randomized to medical treatment, surgery (CABG) or angioplasty (PTCA), with 5 years of follow-up. Cardiovascular death was considered the primary endpoint. Non-fatal myocardial infarction, death and re-intervention were considered for a combined secondary endpoint. The score was based on an equation previously validated, resulting from a sum of one point for: male gender, infarction history, angina, diabetes, insulin use and one point for each decade of life after 40 years old. Positive exercise testing summed one additional point. RESULTS Thirty six deaths was observed (10 in group PTCA, 15 in CABG and 11 in the clinical group), p = 0.61. We observed 93 combined events: 37 in PTCA group, 23 in CABG and 33 in the clinical group (p = 0.058). 247 patients presented clinical score ≥ 5 points and 216 ≥ 6 points. The cutoff point ≥ 5 or ≥ 6 points identified higher risk, p = 0.015 and p = 0.012, respectively. The survival curve showed a different death incidence after the randomization when score reached 06 points or more (p = 0.07), and a distinct incidence of combined events between the patients with score < 6 and ≥ 6 points (p = 0.02). CONCLUSION The new score was consistent for multiarterial stable coronary disease risk stratification.

New prognostic score for stable coronary disease evaluation

FUNDAMENTO: A necessidade de melhorar a acuracia do teste de esforco, determinou o desenvolvimento de escores, cuja aplicabilidade ja foi amplamente reconhecida. OBJETIVO: Avaliacao prognostica do coronariopata estavel atraves de um novo escore simplificado. METODOS: Um novo escore foi aplicado em 372 coronariopatas multiarteriais e funcao ventricular preservada, 71,8% homens, idade media 59,5 (± 9,07) anos, randomizados para angioplastia, revascularizacao cirurgica e tratamento clinico, acompanhados por 5 anos. Obito cardiovascular foi o desfecho primario. Infarto do miocardio nao-fatal, obito e re-intervencao formaram o desfecho combinado secundario. O escore baseou-se numa equacao previamente validada resultante da soma de 1 ponto para: sexo masculino, historia de infarto, angina, diabete, uso de insulina e ainda 1 ponto para cada decada de vida a partir dos 40 anos. Teste positivo adicionou 1 ponto. RESULTADOS: Ocorreram 36 obitos (10 no grupo angioplastia, 15 no grupo revascularizacao e 11 no grupo clinico), p = 0,61. Observou-se 93 eventos combinados: 37 no grupo angioplastia, 23 no grupo revascularizacao e 33 no grupo clinico (p = 0,058). 247 pacientes apresentaram escore clinico > 5 pontos e 216 > 6 pontos. O valor de corte > 5 ou > 6 pontos identificou maior risco, com p = 0,015 e p = 0,012, respectivamente. A curva de sobrevida mostrou uma incidencia de obito apos a randomizacao diferente naqueles com escore > 6 pontos (p = 0,07), e uma incidencia de eventos combinados diferente entre pacientes com escore 6 pontos (p = 0,02). CONCLUSAO: O novo escore demonstrou consistencia na avaliacao prognostica do coronariopata estavel multiarterial.BACKGROUND The need to improve the exercise testing accuracy, pushed the development of scores, whose applicability was already broadly recognized. OBJECTIVE Prognostic evaluation of stable coronary disease through a new simplified score. METHODS A new score was applied in 372 multivessel coronary patients with preserved ventricular function, 71.8% male, age: 59.5 (± 9.07) years old, randomized to medical treatment, surgery (CABG) or angioplasty (PTCA), with 5 years of follow-up. Cardiovascular death was considered the primary endpoint. Non-fatal myocardial infarction, death and re-intervention were considered for a combined secondary endpoint. The score was based on an equation previously validated, resulting from a sum of one point for: male gender, infarction history, angina, diabetes, insulin use and one point for each decade of life after 40 years old. Positive exercise testing summed one additional point. RESULTS Thirty six deaths was observed (10 in group PTCA, 15 in CABG and 11 in the clinical group), p = 0.61. We observed 93 combined events: 37 in PTCA group, 23 in CABG and 33 in the clinical group (p = 0.058). 247 patients presented clinical score ≥ 5 points and 216 ≥ 6 points. The cutoff point ≥ 5 or ≥ 6 points identified higher risk, p = 0.015 and p = 0.012, respectively. The survival curve showed a different death incidence after the randomization when score reached 06 points or more (p = 0.07), and a distinct incidence of combined events between the patients with score < 6 and ≥ 6 points (p = 0.02). CONCLUSION The new score was consistent for multiarterial stable coronary disease risk stratification.

Avaliação não Invasiva de Pacientes Submetidos à Intervenção Percutânea no Infarto do Miocárdio Noninvasive Assessment of Patients Undergoing Percutaneous Intervention in Myocardial Infarction

BACKGROUND Restenosis after primary percutaneous coronary intervention (PPCI) remains an important clinical problem, even with stent implantation. The ability of noninvasive testing to diagnose restenosis has had only inconsistent demonstration. OBJECTIVE Our objective was to evaluate the ability of exercise treadmill testing (ETT) and myocardial perfusion imaging (MPI) to diagnose restenosis in patients treated by PPCI within 12 hours of ST-elevation myocardial infarction (STEMI). METHODS From August 2003 to January 2006, 64 patients (mean age of 56.2±10.2 years, 53 males) were enrolled after PPCI. Only patients with left ventricular ejection fraction (LVEF) > 40%, as assessed by resting transthoracic echocardiography (TTE), were included. ETT with 12-lead ECG monitoring and right precordial leads, as also MPI were performed at 6 weeks, 6 months, and one year after intervention. Coronary angiography was performed at six months. RESULTS Single-vessel disease was observed in 46.9% of the patients. The left anterior descending coronary artery was treated in 48.4% of the patients. Angiographic restenosis occurred in 28.8%. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of ETT in detecting restenosis were not significant. Right precordial leads did not add information. MPI sensitivity, specificity, PPV, NPV, and accuracy correlated with restenosis only in the 6-month follow-up, both when considering summed difference score >2 (p=0.006) and >4 (p=0.014). CONCLUSION ETT did not discriminate restenosis in this population. MPI performed at 6 months correlated with restenosis and proved useful during follow-up.

Stress Modalities to Evaluate Myocardial Perfusion

As discussed in Chapter 1, atherosclerotic lesions appear early in life.1,2 Considering its high incidence, which only increases with aging,3 the active search for coronary lesions, in the asymptomatic general population, does not seem reasonable. Lesions will often be found but will not necessarily be affecting myocardial perfusion in a significant way. Preservation of perfusion relates to other factors, including (1) the capacity of coronary vessels to dilate, known as coronary blood flow reserve (CBFR) and (2) the existence of a complex net of collateral vessels at the microcirculatory level. Whether coronary lesions will adversely affect myocardial blood flow (MBF) depends highly on the impact they have on CBFR and the existence or absence of good-quality collateral vessels. Evaluation of MBF, under stress, helps to determine the presence of coronary artery disease (CAD) affecting CBFR. The extent of myocardial ischemia and the degree of left ventricular dysfunction are key variables for determining prognosis that can be evaluated in nuclear cardiology using myocardial perfusion imaging (MPI). To test CBFR in nuclear cardiology, several stress modalities can be applied, including exercise, dipyridamole, adenosine, exercise combined with dipyridamole or adenosine, and dobutamine. Other less frequent forms of stress such as arbutamine, cardiac pacing, mental stress, and the cold pressor test, have also been used. These stress modalities are reviewed in this chapter.

Chagas' Disease: Update on Current Diagnosis

Purpose of ReviewChagas’ disease has become an emerging health problem due to increased migration. In the present review, we have summarized the usefulness of non-invasive imaging tools for the diagnosis of cardiac involvement in Chagas’ disease, with emphasis on modern technologies. M-mode, bidimensional (2-D), and three-dimensional (3-D) echocardiographies may allow the evaluation of left ventricular (LV) regional and global contractile function, right ventricle (RV) impairment, evidence of aneurysms and thrombi, and assessment of diastolic function in any stage of the disease.Recent FindingsNew modalities such as strain and speckle-tracking imaging have brought non-invasive indices to the understanding of the mechanisms of cardiac dyssynchrony. The assessment of cardiac autonomic denervation using 123I-metaiodobenzylguanidine (123I-MIBG), LV, and RV systolic function and the study of LV mechanical dyssynchrony by gated cardiac blood pool are available in current nuclear imaging for patients with Chagas’ disease. The findings of myocardial fibrosis by cardiac magnetic resonance (CMR), mainly in inferolateral regions, are a marker of subclinical involvement and worse prognosis in Chagas’ disease, even in patients with preserved ventricular function.SummaryThe detection and quantification of early signs of heart involvement by new technologies should be useful for risk stratification and in the clinical decision process for new therapeutic methods and could improve the natural history of the disease.

INFLUENCE OF LEFT BUNDLE BRANCH BLOCK IN ASSESSMENT OF MYOCARDIAL BLOOD FLOW FROM RUBIDIUM 82 POSITRON EMISSION TOMOGRAPHY IMAGING

Perfusion defects are frequent in myocardial scintigraphy in left bundle branch block (LBBB) patients. However, scarce studies show decreased coronary flow reserve (CFR) in the left anterior descending artery territory, regardless of the presence of coronary artery disease (CAD). We sought to