Routine perioperative dipyridamole Tl-201 imaging in diabetic patients undergoing vascular surgery - Is it necessary?

OBJECTIVE - To assess the utility of dipyridamole thallium testing in symptomatic and asymptomatic patients with diabetes undergoing vascular surgery. RESEARCH DESIGN AND METHODS - Dipyridamole Tl-201 myocardial scintigraphy was performed preoperatively in 93 consecutive patients with diabetes undergoing peripheral vascular procedures. The utility of clinical and thallium variables in predicting cardiovascular complications was assessed. RESULTS - Two groups oi patients were identified: group A (36 patients) without clinical evidence of cardiac disease and group B (57 patients) with clinical evidence of cardiac disease. Dipyridamole thallium scans were abnormal in 21 of 36 (58%) of group A patients compared with 53 of 57 (93%) of group B patients (P < 0.0001). Compared with group B patients with perfusion defects, group A patients with perfusion abnormalities tended to have fewer defects per scan (2.7 +/- 1.5 vs. 3.6 +/- 1.9, P = 0.05). No perioperative cardiac complications occurred in group A patients while perioperative cardiac complications occurred in 9 of 57 (16%, 95% CI 7-28%) group B patients (P = 0.01). For the entire study population, the complication rate was 10%. CONCLUSIONS - Diabetic individuals without clinical markers for coronary artery disease appear to be at low risk for adverse postoperative cardiac events after vascular surgery. Preoperative myocardial perfusion imaging may add little to cardiovascular risk assessment in this subgroup of patients with diabetes.