Abstract 6270: How Many Guidelines Does it Take to Send an Asymptomatic Man to Invasive Angiography?
Modern medical practice utilizes peer-reviewed published guidelines in order to establish if a diagnostic test or therapeutic intervention is appropriate and will likely promote better outcomes in patient care. However, some evidence-based recommendations may lead to incremental health care cost and potential patient harm if applied blindly, without the guidance of clinical judgment. To analyze the epidemiologic impact of applying the diagnostic algorithm for coronary artery disease (CAD) management suggested by the Screening for Heart Attack Prevention and Education (SHAPE) task force. Using data from the National Health and Nutrition Examination Survey (NHANES) and the Multi-Ethnic Study of Atherosclerosis (MESA), we assessed the hypothesis that proceeding with further diagnostic evaluation via stress testing in patients who have a coronary calcium score greater than 400 on CT scanning would lead to a remarkable number of invasive procedures performed in an asymptomatic population who is deemed to have low risk for cardiovascular events according to other published guidelines. According to the MESA database and the NHANES data collected up to 2002, 4.6 million American men between ages 45 and 79-years-old have a calcium score greater than 400 on coronary CT imaging, which corresponds to approximately 12 % of the population in that group. Potentially 10 to 12 % of those asymptomatic individuals could have false positive stress tests, leading to almost half a million cardiac catheterizations performed in asymptomatic adult males, with a sizable absolute number of procedure-related cost and complications. The decision to follow diagnostic algorithms in the care of patients with risk factors for coronary artery disease should focus great attention to the type of population being studied, the pre-test probability of disease, the cost-benefit relationship and the risk-benefit ratio. If these epidemiologic and health policy parameters are ignored or underestimated, the feasibility of medical practice (using coronary artery disease management as an example) could be compromised in the long-term, despite minimal or no deviation from established standards of care.