Comparison of Prognostic Value of Pharmacologic Stress Echocardiography in Chest Pain Patients With Versus Without Diabetes Mellitus and Positive Exercise Electrocardiography

The aim of this study was to compare the prognostic value of pharmacologic stress echocardiography in diabetic and nondiabetic patients with chest pain and intermediate- to high-threshold positive exercise electrocardiographic results. A total of 935 patients with chest pain (131 diabetic patients) with ST-segment depression ≥1 mm on exercise electrocardiography at ≥75-W workload underwent dipyridamole (n = 786) or dobutamine (n = 149) stress echocardiography and were followed up for the occurence of hard (death and infarction) and major events (death, infarction, and late revascularization). During a median follow-up of 26 months, 158 events (51 deaths, 28 myocardial infarctions, and 79 late revascularizations) occurred: 34 in diabetic and 124 in nondiabetic patients (26% vs 15%, p = 0.003). Independent predictors of hard events were age, diabetes, and ischemia at stress echocardiography. Five-year hard event rates were 24% in patients with and 4% in those without ischemia (p <0.0001). Independent predictors of major events were age, diabetes, hypercholesterolemia, smoking habit, antianginal therapy at the time of testing, and ischemia at stress echocardiography. Five-year major event rates were 46% in patients with and 7% in those without ischemia (p <0.0001). Stress echocardiography results yielded effective prognostic information in diabetic and nondiabetic patients. However, the latter had worse outcomes in both the presence and absence of ischemia. Nevertheless, a nonischemic test result predicted an uneventful 6-month period and 2% major event rate at 1-year follow-up in both populations. In conclusion, stress echocardiography was effective in risk stratifying diabetic and nondiabetic patients with intermediate- to high-threshold ischemic exercise electrocardiographic results. However, major event rates associated with a nonischemic test result were similar in diabetic and nondiabetic patients during the first year of follow-up and markedly increased in the former thereafter.