Prevalence of silent myocardial ischaemia in new-onset middle-aged Type 2 diabetic patients without other cardiovascular risk factors

Aims Coronary artery disease (CAD) is the leading cause of death in patients with Type 2 diabetes and is often asymptomatic. Silent myocardial ischaemia (SMI) is frequent in diabetic subjects and is responsible for a late diagnosis of CAD; its early detection is important. There are some data about the prevalence of SMI in Type 2 diabetic patients at high risk for cardiovascular disease, while no data are available in subjects at the onset of diabetes without other cardiovascular risk factors. Methods We screened 274 consecutive patients (mean age 64.3 +/- 8.4 years, 66% male) at the time of diagnosis of Type 2 diabetes; we enrolled 111 subjects without other cardiovascular disease risk factors (dyslipidaemia, hypertension, peripheral vascular disease, retinopathy, microalbuminuria, history of heart disease) and with normal resting electrocardiogram (ECG). Participants performed a maximal ECG exercise protocol and, if positive, underwent coronary angiography. Results The ECG exercise test was positive in 19 patients (17.1%); of those 14 (13%) had angiographic coronary disease (one with three-vessel disease, three with two vessels and 10 with one vessel involved). The positive predictive value of the exercise ECG for predicting angiographic coronary disease was 73%. Conclusions The prevalence of SMI was 17% and angiographic coronary disease was found in 13% of middle-aged subjects with new-onset Type 2 diabetes without other cardiovascular risk factors. This prevalence is similar to that observed in studies of subjects with long duration diabetes who have additional cardiovascular risk factors.