The potential of myocardial perfusion scintigraphy for risk stratification of asymptomatic patients with type 2 diabetes

Patients with diabetes, in particular patients with type 2 diabetes, are at a 2- to 4-fold higher risk of cardiovascular mortality compared with their nondiabetic peers. Patients with diabetes are also more likely to have silent ischemia and less likely to survive a myocardial infarction than nondiabetic patients. Recent studies with electron beam computed tomography (EBCT) have shown that subclinical atherosclerosis is common in patients with diabetes, and studies with myocardial perfusion scintigraphy (with single-photon emission computed tomography) or stress echocardiography have demonstrated that between 25% and 50% of asymptomatic diabetic patients have ischemia during exercise or pharmacological stress and that a substantial proportion of these patients go on to develop major cardiovascular events within several years. Clearly, asymptomatic diabetic patients include a subset of individuals at high risk of cardiovascular disease who would benefit from improved risk stratification beyond that possible with risk factor scoring systems alone. Single-photon emission computed tomography, stress echocardiography, and possibly EBCT or multi-slice computed tomography, are emerging as valuable diagnostic tools for identifying asymptomatic diabetic patients who might require early and aggressive intervention to manage their cardiovascular risk.