Screening for Coronary Artery Disease in Type 2 Diabetes

CLINICAL CONTEXT: Sensitive tools are available to diagnose occult ischemic and atherosclerotic coronary disease, yet screening for coronary artery disease (CAD) has not been shown to reduce cardiac events in patients with type 2 diabetes mellitus (T2DM). Professional guidelines are inconsistent regarding CAD screening recommendations, but it is suggested that those at highest risk (10-yr risk ≥20%) for cardiac events may benefit. EVIDENCE ACQUISITION: We reviewed bibliographies of professional CAD screening guidelines, review articles, and clinical trials published within the last 10 yr, although we have included relevant older studies. We excluded studies that did not focus on T2DM or explicitly analyze that subgroup. EVIDENCE SYNTHESIS: Although screening for coronary ischemia or atherosclerosis does provide incremental prognostic information in patients with T2DM and previously undiagnosed CAD, this has not been found to significantly impact outcomes. This appears to result from comparable efficacy of revascularization and optimal medical therapy in stable CAD. Limited evidence supports the hypothesis that those with more severe CAD (three-vessel, left main, proximal left anterior descending) amenable to bypass surgery may be potential beneficiaries of screening. However, the low prevalence of such candidates in the asymptomatic population, continuing advances with percutaneous intervention, and the lack of prospective trials makes such a recommendation currently unsupportable. CONCLUSIONS: Findings to date do not support widespread screening for CAD in patients with T2DM. A future strategy identifying those at highest risk as screening candidates may ultimately be effective, but the optimal method for selecting those subjects or subsequent treatment is unknown.