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 ± 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 follow-up, 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 < 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 X2 = 7, P < 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.