Stress Echocardiography for Risk Stratification of Diabetic Patients With Known or Suspected Coronary Artery Disease

Abstract

OBJECTIVE -Coronary artery disease (CAD) is a leading cause of mortality and morbidity in diabetic patients; therefore, their risk stratification is a relevant issue. Because exercise tolerance is frequently impaired in these patients, pharmacological stress echocardiography (SE) has been suggested as a valuable alternative. Our aim was to evaluate the prognostic value of this technique in diabetic patients with known or suspected CAD. RESEARCH DESIGN AND METHODS-A total of 259 consecutive diabetic patients underwent pharmacological SE (dobutamine in 108 patients and dipyridamole in 151 patients) and follow-up for 24 Ϯ 22 months. A comparison between the prognostic value of SE and exercise electrocardiography (ECG) was made in a subgroup of 120 subjects.RESULTS -A total of 13 cardiac deaths and 13 nonfatal infarctions occurred during followup, and 58 patients were revascularized. Univariate predictors of outcome were known CAD, positive SE, rest and peak wall motion score index (WMSI), and peak/rest WMSI variation. Peak WMSI was the only significant and independent prognostic indicator (odds ratio 11; 95% CI 4 -29, P Ͻ 0.0001) on multivariate Cox's analysis. After adjustment for the most predictive clinical and exercise ECG variables, SE provided 43% additional prognostic information (gain in X 2 ϭ 7, P Ͻ 0.01). Moreover, positive SE was associated with a significantly lower event-free survival.CONCLUSIONS -SE effectively predicts cardiac events in diabetic patients with known or suspected CAD and adds additional prognostic information as compared with exercise ECG. Diabetes Care 24:1596 -1601, 2001C ardiovascular disease is the leading cause of death in patients with diabetes (1-3); in particular, coronary artery disease (CAD) is the cause of death in more than half of these patients (4). Diabetes is present in as many as 30% of patients hospitalized because of acute coronary syndromes (5) and is associated with greater mortality during the acute phase of myocardial infarction and a higher morbidity in the postinfarction period (6,7). The risk of adverse outcome is independent of the conventional risk factors for CAD (8): patients with diabetes but without other risk factors for atherosclerosis have a chance of death from CAD two to four times that of age-matched controls (4). Although revascularization procedures are associated with greater long-term mortality (9 -11), coronary artery bypass grafting can improve survival in diabetic patients with multivessel CAD (12). Therefore, assessing risk for cardiac events in these patients is a relevant clinical issue. Scintigraphic imaging techniques have greater prognostic value than exercise electrocardiography (ECG) in diabetic patients (13), whereas prognostic studies with stress echocardiography (SE) are still lacking, despite the proven safety, feasibility, and diagnostic effectiveness of this technique (14,15).The purpose of this study was twofold: 1) to assess the long-term prognostic value of SE in diabetic patients with known or suspected CAD and 2) to compar...

Stress Testing in Patients With Diabetes Mellitus

“…Quantification of ischemia using a wall-motion score index on DSE (with higher numbers reflecting increasingly abnormal wall motion at peak exercise) offered significant additional prognostic value for cardiac events ( 2 37 versus 18, PϽ0.05) and all-cause mortality ( 2 52 versus 43, PϽ0.05). Bigi et al 46 also assessed the value of pharmacological stress echocardiography for risk stratification of diabetic patients with known or suspected CAD. A total of 259 patients with DM underwent dobutamine (42%) or dipyridamole (58%) stress echocardiography and were followed up for a mean of 2 years for cardiac death and nonfatal MI.…”

Prognostic Value of Dobutamine Stress Echocardiography in Patients With Diabetes

“…Conversely, Bates et al (16) reported that DSE was a powerful test for the prognostic stratification of 53 patients with juvenileonset insulin-dependent diabetes who were considered for kidney and/or pancreas transplantation. Recently, Bigi et al (22) studied 108 diabetic patients who were followed-up for 20 Ϯ 17 months after DSE and 151 diabetic patients who were followed-up for 33 Ϯ 26 months after dipyridamole stress test. Cox's model selected peak wall motion score index as the only significant independent predictor of cardiac events.…”

Burgeoning Dilemmas in the Management of Diabetes and Cardiovascular Disease

“…Surprisingly, stress tests are positive in only 30% to 50% of patients with diabetes, even when symptoms compatible with coronary artery disease are present. 38,39 In those patients with positive stress tests, specificity is less than optimal. If coronary disease is documented by stress testing, patients must then agree to undergo coronary arteriography.…”