Comparison of coronary collateral circulation in diabetic and nondiabetic patients suffering from coronary artery disease

Background and hypothesis: Although it is well established that diabetes me llitus (DM) induces more severe coronary artery disease (CAD), it is not kn own whether it contributes to the development of coronary collateral circul ation. The pre sent study examines coronary collateral circulation in diabe tic and nondiabetic patients with angiographically verified CAD. Methods: The study group consisted of 463 diabetic patients (382 men, 81 wo men) with a mean age of 60.3 +/- 8.8 years, and 227 nondiabetic subjects (1 59 men, 68 women) with a mean age of 59.2 +/- 9 years. The extension and fu nctional capacity of coronary collateral circulation was assessed according to the Cohen and Rentrop grading system of 0 to III. Results: We found that diabetic patients had grade III collateral circulati on more frequently than nondiabetic subjects (13.2 vs. 8.5%, p < 0.01). Thi s finding was even more pronounced in diabetic men aged <55 years compared with both nondiabetic men (20 vs. 3.4%, p < 0.001) and diabetic women (20 v s. 2.2%, p < 0.001). Grade III collateral circulation was found to develop mainly at the left anterior descending (LAD) coronary artery and the right coronary artery (RCA), where complete occlusions of coronary arteries usual ly occur. Conclusions: Diabetic patients with CAD develop more extensive coronary col lateral circulation than nondiabetic subjects, especially men aged <55 year s. The collateral circulation mainly develops at the LAD and RCA.