Diagnostic and prognostic value of vasodilator stress echocardiography in asymptomatic Type 2 diabetic patients with positive exercise thallium scintigraphy: a pilot study

Aim To assess the diagnostic and prognostic value of vasodilator stress echocardiography in Type 2 diabetic patients with positive exercise perfusion scintigraphy. Methods Of an initial cohort of 50 asymptomatic Type 2 diabetic patients undergoing exercise single photon emission computed tomography (SPECT) thallium scintigraphy, 24 had a positive thallium scan, with a reversible perfusion defect. All these 24 underwent high dose (up to 0.84 mg/kg in 10 min) dipyridamole echocardiography and coronary angiography independently of stress echocardiography results. All patients were then followed for 61 +/- 22 months. Results Coronary angiography showed normal corollary arteries in 11 patients and significant (> 50% visually assessed diameter reduction in a major vessel) coronary artery disease in 13. Stress echocardiography showed 92% sensitivity and 100% specificity for non-invasive detection of coronary artery disease. During fellow-up, five patients experienced cardiac events: heart failure in one, angina with subsequent revascularization in two, and myocardial infarction in two. Event-free survival was 100% in the 12 patients with negative and 58% in the 12 patients with positive stress echocardiography (P = 0.08 by Mantel-Cox test). Conclusions In asymptomatic Type 2 diabetic patients with stress-induced perfusion defects, vasodilator stress echocardiography is an excellent diagnostic and prognostic tool proven with long-term follow-up.