Prognostic Value of Epicardial Coronary Artery Constriction to the Cold Pressor Test in Type 2 Diabetic Patients With Angiographically Normal Coronary Arteries and No Other Major Coronary Risk Factors

OBJECTIVE: Endothelium-dependent coronary dilation is impaired in diabetic patients and has been found to independently predict cardiovascular events (CVEs) in patients with multiple coronary risk factors. The aim of this study was to evaluate the outcome of type 2 diabetic patients on the basis of epicardial coronary dysfunction. RESEARCH DESIGN AND METHODS: We examined 56 control subjects (aged 51.7 +/- 6.4 years) using coronary artery response to the cold pressor test (quantitative coronary angiography) and compared them with 72 type 2 diabetic patients (aged 50.3 +/- 8.5 years) without other major coronary risk factors. RESULTS: Average diameter change was 17.2 +/- 10.4% in the control subjects, dilation occurred in 91.1% of subjects, no change occurred in 8.9%, and there was no constriction. Average diameter change was -14.4 +/- 12.1% in diabetic patients (P < 0.001 vs. control subjects), constriction occurred in 73.6%, no change occurred in 26.4%, and there was no dilation. CVEs were recorded with a mean follow-up of 45 +/- 19 months. There was 1 CVE in the control group and 26 CVEs in 18 of 72 diabetic patients (P < 0.001 vs. control subjects), with 23 events in 16 of 53 diabetic patients with coronary artery constriction (P < 0.001 vs. control subjects), and 3 events in 2 of 19 diabetic patients with no diameter change (NS vs. control subjects). CONCLUSIONS: In type 2 diabetic patients without other major coronary risk factors, constriction of angiographically normal coronary arteries to the cold pressor test is predictive of long-term CVEs.