CORONARY-ARTERY DISEASE IN DIABETIC-PATIENTS WITH LOWER-EXTREMITY ARTERIAL-DISEASE - DISEASE CHARACTERISTICS AND SURVIVAL - A REPORT FROM THE CORONARY-ARTERY SURGERY STUDY (CASS) REGISTRY

OBJECTIVE - Patients who have diabetes and lower-extremity arterial di sease (LEAD) are at an increased risk of dying from coronary artery di sease (CAD). This study was undertaken to: 1) define the clinical and arteriographic factors associated with LEAD among diabetic patients; 2 ) determine the long-term survival and predictors of mortality of diab etic patients with LEAD, compared to those without LEAD; and 3) determ ine if the presence of LEAD is an independent risk factor for mortalit y among diabetic patients with CAD. RESEARCH DESIGN AND METHODS - A to tal of 263 diabetic patients from the Coronary Artery Surgery Study (C ASS) registry with LEAD, who were greater than or equal to 50 years of age, and who had arteriographically proven CAD, were identified and f ollowed for a mean of 12.8 years. A total of 1,349 comparably aged dia betic patients from the CASS registry with CAD and no evidence of LEAD were followed for an equivalent period of time. RESULTS - Compared wi th diabetic patients without LEAD, diabetic patients with LEAD were ch aracterized by the presence of cerebrovascular disease, a high rate of current smoking, elevated systolic blood pressure, high grades of ang ina pectoris, and digitalis use. Severity of epicardial CAD and extent of CAD were not independent predictors of the presence of LEAD. On fo llow-up, diabetic patients with LEAD had significantly higher mortalit y (mostly cardiovascular) than diabetic patients without LEAD, with a median survival of 8.1 and 10.9 years, respectively On multivariate an alysis, age, the number of significantly narrowed coronary arteries, a nd the presence of left ventricular dysfunction predicted mortality in both subsets of diabetic patients. Among all the diabetic patients wi th CAD, the presence of LEAD was an independent risk factor for mortal ity. CONCLUSIONS - Diabetic patients with LEAD have a higher mortality rate (mostly cardiovascular) than diabetic patients without LEAD, des pite no apparent anatomic differences in the severity and extent of CA D. This suggests that factors associated with the presence of LEAD, ot her than the anatomy of the coronary circulation, may play a role in d etermining survival among diabetic patients with LEAD and CAD.