Outcome Prediction in Asymptomatic Diabetics: Coronary and Microvascular Events and Coronary CT Angiography

Type 2 diabetics have an increased burden of coronary atheroma and its extent is a determinant of coronary heart disease (CHD) outcomes. However it is uncertain to what extent tighter control of diabetes might modify this relationship and if there is any relationship with microvascular outcomes. This analysis examines the role of glycated hemoglobin (HbAlc) at baseline and during follow-up, as a predictor of (CHD) and microvascular related outcomes, both univariably and independently from baseline risk and total volume of coronary atheroma. A population based cohort of asymptomatic type 2 diabetics (N=630) underwent baseline risk assessment (United Kingdom Prospective Diabetes Study Coronary Heart Disease risk score) (UKPDS) and total coronary artery plaque volume was measured on CT angiography. Control of diabetes was measured by HbAlc at baseline and over the follow-up period. A coronary heart disease event was defined as cardiovascular death, myocardial infarction, unstable angina or new angina requiring revascularization. A microvascular event was defined as therapy for retinopathy or intraocular vascular event or hospitalization for renal failure. Coronary heart disease events were predicted by the UKPDS CHD risk score and independently by coronary plaque volume. Microvascular events were predicted by the UKPDS CHD risk score and independently by higher HbAlc but not by coronary plaque extent. Poorer glycemic control during follow-up predicted microvascular events independently of the baseline UKPDS risk score but had no impact on CHD events. Thus, this study demonstrated distinct predictors of CHD and microvascular events and the latter were unrelated to coronary CT angiographic findings.