The impact of site and extent of clinically evident cardiovascular disease and atherosclerotic burden on new cardiovascular events in patients with Type 2 diabetes. The SMART study

Aims  Patients with Type 2 diabetes and coronary heart disease (CHD) have an excess cardiovascular risk. The relationship of both other sites [cerebrovascular disease, peripheral arterial disease (PAD)] and the extent of clinically evident cardiovascular disease (CVD) with the occurrence of new cardiovascular events have not been investigated previously in patients with diabetes. We aimed to quantify this relationship and to assess the additional influence of atherosclerotic burden. Methods  From 1996 to 2005, 776 patients with Type 2 diabetes with (n = 458) and without (n = 318) clinically evident CVD were followed prospectively for cardiovascular events (cardiovascular death, non-fatal ischaemic stroke or myocardial infarction). CVD was classified according to the site (cerebrovascular disease, CHD, PAD); the extent of atherosclerosis was expressed as the number of affected sites. Carotid intima-media thickness and albuminuria were used as markers of atherosclerotic burden. Results  Compared with patients with diabetes without CVD, the hazard ratio (HR) for a cardiovascular event was 3.8 (95% confidence interval 1.7, 8.5), adjusted for age, gender and potential confounders, in those with cerebrovascular disease, 4.3 (1.9, 9.5) in those with CHD, and 4.6 (2.1, 10.2) in those with PAD. Findings were similar after additional adjustment for atherosclerotic burden. Adjusted HR was 3.4 (1.6, 6.9) for patients with diabetes with one affected site and 6.6 (3.0, 14.3) for those with two or more sites. Conclusions  Patients with Type 2 diabetes and cerebrovascular disease, CHD or PAD have strongly increased risks for future cardiovascular events which are comparable. This risk increases markedly with the number of different cardiovascular sites affected and is irrespective of atherosclerotic burden.