Aims: Information on the clinical outcomes of type 2 diabetic patients (T2DM) with silent myocardial ischemia is limited. We compared the clinical and angiographic characteristics, and the clinical outcomes of T2DM with asymptomatic or symptomatic coronary artery disease (CAD).
Methods and Results: Three hundred and ten consecutive cases of T2DM with CAD were divided into two groups according to the presence of angina and followed for an average of 5 years. Fifty-six asymptomatic T2DM (ASx-CAD group) with a positive stress test and CAD on coronary angiography were compared with 254 symptomatic T2DM (Sx-CAD group). ASx-CAD group of patients had longer duration of diabetes and slightly poor glycemic control, and higher prevalence of LV dysfunction and renal insufficiency than Sx-CAD. There was no significant difference in the coronary atherosclerosis severities, which was evaluated by the number of diseased vessel and Gensini score. However, ASx-CAD group received revascularization therapy less frequently than Sx-CAD group (26.8% vs 62.0%, p<0.001). ASx-CAD group experienced similar number of major adverse cardiac events (death, non-fatal myocardial infarction, and revascularization), but had higher cardiac mortality than Sx-CAD group (32% vs 28%, p=0.57; 26% vs 9%, p<0.001, respectively). However, patients who underwent revascularization therapy at the time of CAD diagnosis in these two groups showed similar clinical outcomes (20.0% vs 22.5% in MACE; 6.7% vs 5.3% in cardiac death; 13.3% vs 16.6% in late revascularization therapy; all p=not significant).
Conclusion: Diabetic patients with ASx-CAD had higher cardiac mortality risk than those with Sx-CAD, and infrequent revascularization therapy in these patients might be the cause of their poor survival. Therefore, we suggest that diabetics with asymptomatic CAD should be screened earlier and be treated by revascularization therapy as frequent as those with Sx-CAD.