Prognostic value of dobutamine stress echocardiography in diabetic patients

CAD is the main cause of morbidity and mortality in diabetic patients; we need reliable clinical parameters to stratify cardiovascular risk in these patients. We thus assessed prognostic value of clinical parameters, rest and stress echocardiographic data in diabetic patients, with known or suspected CAD. We studied 322 type 2 diabetic patients, who underwent dobutamine stress echocardiography (DSE) for known or suspected CAD; for prognostic assessment, end-points were all-cause mortality and hard cardiac events (cardiac death and non fatal myocardial infarction). During DSE, viability and inducible ischemia developed in 65 (20%) and 192 (60%) subjects, respectively; a severe ischemia (an asynergic area including more than 40% of all segments combined with a rate pressure product < 17,000) appeared in 88 (27%). Presence of a diabetic treatment or microvascular diabetic complications didn't influence prognosis, while a longer diabetes duration was associated with a higher all-cause mortality at univariate analysis. At multivariate analysis, an advanced age (RR = 1.108, CI: 1.039-1.182, P = 0.002), a lower left ventricular ejection fraction (RR = 0.956, CI: 0.919-0.994, P = 0.025) and, tendentially, peripheral vascular disease (RR = 2.942, CI: 0.985-8.785, P = 0.053) independently determined an increased all-cause mortality. New hard cardiac events occurred more frequently in presence of peripheral vascular disease (RR = 2.975, CI: 1.339-6.608, P = 0.007), viability (RR = 3.427, CI: 1.400-8.390, P = 0.007) and severe ischemia (RR = 3.245, CI: 1.503-7.005, P = 0.003). In diabetic patients with known or suspected CAD, presence of viability and severe ischemia during DSE are independently associated with higher occurrence of hard cardiac events.