802-1 Clinical Value and Cost of Screening Exercise Treadmill Testing in Asymptomatic Individuals

Abstract

Exercise treadmill testing (ETT) is frequently performed to screen for coronary artery disease (CAD) in asymptomatic individuals; however, its clinical value is questionable. To evaluate the clinical value of ETT, we examined a cohort of asymptomatic individuals undergoing ETT at the Cleveland Clinic between September 1990 and December 1993. ETT was abnormal if it exhibited any of the following; a 1 mm ST-T elevation or depression, a drop in blood pressure ≥10 mmHg, chest pain or failure to reach a target heart rate. Any CAD was defined by at least 1 coronary segment with ≥50% stenosis. Severe CAD was defined by the following: 1) left main coronary artery with ≥50% stenosis, 2) 3 vessels with ≥70% stenosis or 3) proximal left anterior descending artery and 2 vessels with ≥70% stenosis. During this period, 4335 ETT's were performed in individuals with no cardiac symptoms. The average age was 53, 89% were male and 16% had at least one cardiac risk factor. Fifteen percent exhibited an abnormal ETT. Among those with an abnormal ETT, 14% underwent coronary angiography while among those with a negative ETT, 1% underwent angiography. Coronary angiography identified 56% as having any CAD and 15% as having severe CAD. In this asymptomatic population, 228 ETT's and 7 coronary angiograms were performed in order to identify 1 individual with severe CAD. Using Medicare reimbursement of $70 for ETT and $1500 for angiography, the cost of screening per case of severe CAD identified would be $26,460. Based on previously published data on survival with surgical and medical therapy in patients with severe CAD, we estimate a cost of $120,000 to $180,000 per year of life saved with this screening approach. This low yield suggests that screening asymptomatic individuals with ETT may be costly and of little clinical value compared to other screening approaches.