Ethical considerations in image-based screening for coronary artery disease

Despite marked advances in the treatment and prevention of coronary artery disease (CAD) during the last decade, CAD and its complications continue to account for 20% of all deaths in the United States, more than other cause of death. Moreover, half of those who die suddenly of an acute myocardial infarction have no prior symptoms or overt manifestations of their underlying CAD. As our understanding of the pathophysiology of coronary atherosclerosis improves, diagnostic tests utilizing magnetic resonance (MR) imaging and gated computed tomography are being developed to screen for significant CAD in symptomatic individuals and in those who are preclinical or asymptomatic. Patients with known or suspected CAD might be candidates for MR studies of myocardial perfusion, myocardial contraction under stress, MR coronary arteriography, and plaque characterization. One rationale would be to uncover patients before they have a silent heart attack to institute preventative therapies. Although clinical studies have not definitively demonstrated the efficacy of these modalities, screening sites are proliferating and patients are demanding screening tests for CAD. Radiologists interpreting these tests should understand their underlying rationale, the data referenced to substantiate their use, and their responsibility to inform the patient of the results. This review describes current concepts of the pathophysiology of CAD, the rationale for the various screening tests for CAD that are in use or in development, and the potential value of the results of screening to individual patients. The ethical issues embodied in the performance of screening tests for CAD are placed in the context of the appropriate role of the radiologist as a physician interacting directly with a patient.