Diabetes and Cardiovascular Disease

Abstract

This is the second of a series of articles based on presentations at the American Diabetes Association (ADA) 70th Scientific Sessions, held 25–29 June 2010 in Orlando, Florida, pertaining to cardiovascular disease (CVD). At a symposium on the relationship between diabetes and CVD, Silvio E. Inzucchi, New Haven, CT, reviewed findings of the Detection of Ischemia in Asymptomatic Diabetes (DIAD) study. Coronary artery disease (CAD) is a leading cause of morbidity and mortality, but a concern is that myocardial ischemia may be silent, with its first presentation an acute myocardial infarction or sudden death. If CAD can be identified in a preclinical stage, identifying patients with silent ischemia might lead to benefits beyond that from intensive risk factor reduction, perhaps leading to “more serious” risk factor treatment, both on the part of the physician and on the part of the patient, or, perhaps, to benefits beyond that from recommending revascularization. Screening can involve electrocardiographic exercise testing, myocardial perfusion imaging or stress echocardiography after adenosine or exercise, or computed tomography angiography. There were three portions to the DIAD study; the first described the prevalence and predictors of silent ischemia, the second identified which factors were associated with progression and which with regression of CAD, and the third addressing the question of whether cardiac event rates were affected by screening versus not screening among individuals with type 2 diabetes. With adenosine-sestamibi single photon emission computed tomography myocardial perfusion imaging (MPI), DIAS endeavored to identify high-risk patients based on conventional risk factors. The study included 1,123 eligible type 2 diabetic patients age 50–75 years without a history of CAD and with a normal resting electrocardiogram, randomized to undergo or not undergo MPI (1). Of 522 screened, 113 (22%) had abnormalities, substantially fewer than the 50–60% anticipated, with 83 showing perfusion abnormality, and 30 …