Different prognostic value of silent peripheral artery disease in type 2 diabetic and non-diabetic subjects with stable cardiovascular disease

ObjectiveABI is a good predictor of morbidity and motality in diabetic subjects with no known cardiovascular disease. However, its prognostic value in diabetic patients with prior coronary or cerebrovascular disease has not previously been evaluated.MethodsMulticenter, prospective study of 1 year of follow-up, in 1096 patients (73.6 years, 65% males, 45.4% with diabetes) with cardiovascular disease and without known peripheral arterial disease. The main outcome measure was the first occurrence of a major cardiovascular event (non-fatal acute coronary syndrome, non-fatal stroke, revascularization procedure, or cardiovascular death). Secondary endpoints included major cardiovascular events, cardiovascular death and death from any cause.ResultsPrevalence of an abnormal ABI (<0.9 or >1.4) was 38.2% in diabetic and 26.8% in non-diabetic subjects. There were 150 major cardiovascular events (38.3/1000 person-years in diabetics vs. 30.6/1000 person-years in non-diabetics subjects, p = 0.012) and 60 cardiovascular deaths (11.8/1000 person-years in diabetics vs. 10.7/1000 person-years in non-diabetics subjects, p = 0.156). Patients with abnormal ABI had a higher rate of vascular complications. There was a significant interaction between ABI and diabetes. In non-diabetic patients, an abnormal ABI was associated with an increase risk of the primary endpoint (HR 2.71; 95% CI 1.54-4.76), cardiovascular mortality (HR 4.62; 95% CI 1.47-14.52) and total mortality (HR 2.80; 95% CI 1.08-7.27). These associations were not observed in patients with diabetes.ConclusionIn patients with cardiovascular disease, ABI is a good predictor of risk of recurrent cardiovascular events and death, only in non-diabetic subjects.