Extent of coronary artery disease is associated with myocardial infarction and mortality in patients with diabetes mellitus

Purpose: We examined risk of myocardial infarction and all-cause death associated with the extent of coronary artery disease ascertained by coronary angiography in patients with diabetes mellitus. We hypothesized that risks of myocardial infarction and death were associated with extent of coronary artery disease in diabetes patients. Patients and methods: We conducted a cohort study of patients with type 1 and type 2 diabetes, who underwent coronary angiography from 2004 to 2012. Patients were stratified according to extent of coronary artery disease: 0-, 1-, 2- or 3-vessel disease or diffuse vessel disease. Endpoints were myocardial infarction, all-cause death, and major adverse cardiovascular events (MACE), defined as the composite of myocardial infarction, cardiac death, or ischemic stroke. Adjusted incidence and mortality rate ratios (IRRs(adj)) were calculated using patients with 0-vessel disease as the reference group. Median follow-up was 3 years for a total of 45,164 person-years. Results: The study included 12,594 diabetes patients. Of these, 3,147 (25.0%) had 0-vessel disease, 1,195 (9.5%) had diffuse vessel disease, 3,001 (23.8%) had 1-vessel disease, 2,220 (17.6%) had 2-vessel disease, and 3,031 (24.1%) had 3-vessel disease. The myocardial infarction rate was 0.4 per 100 person-years (95% CI: 0.3–0.5) in patients with 0-vessel disease. Using patients with 0-vessel disease as reference, the risk of myocardial infarction increased according to the number of diseased vessels (diffuse vessel disease: 1.4 per 100 person-years, IRR(adj) 3.87, 95% CI: 2.41–6.23; 1-vessel disease: 1.9 per 100 person-years, IRR(adj) 4.99, 95% CI: 3.33–7.46; 2-vessel disease: 2.7 per 100 person-years, IRR(adj) 7.14, 95% CI: 4.78–10.65; and 3-vessel disease: 4.3 per 100 person-years, IRR(adj) 11.42, 95% CI: 7.76–16.82; p(trend)<0.001). Similar associations were observed for all-cause death and MACE. Conclusion: The extent of coronary artery disease is a major risk factor for myocardial infarction and death in patients with diabetes mellitus.