Exercise tolerance testing to screen for coronary heart disease: a systematic review for the technical support for the U.S. Preventive Services Task Force.

BACKGROUND Coronary heart disease is the leading cause of morbidity and mortality in the United States. Exercise tolerance testing has been proposed as a means of better identifying asymptomatic patients at high risk for coronary heart disease events. PURPOSE To review the evidence on the use of exercise tolerance testing to screen adults with no history of cardiovascular disease for coronary heart disease. DATA SOURCES The MEDLINE database from 1966 through February 2003, hand-searching of bibliographies, and expert input. STUDY SELECTION Eligible studies evaluated the benefits or harms of exercise tolerance testing when added to traditional risk assessment for adults with no known history of cardiovascular events. DATA EXTRACTION One reviewer extracted information from eligible articles into evidence tables, and another reviewer checked the tables. Disagreements were resolved by consensus. DATA SYNTHESIS No study has directly examined the effect of screening asymptomatic patients with exercise tolerance testing on coronary heart disease outcomes or risk-reducing behaviors or therapies. Multiple cohort studies demonstrate that screening exercise tolerance testing identifies a small proportion of asymptomatic persons (up to 2.7% of those screened) with severe coronary artery obstruction who may benefit from revascularization. Several large prospective cohort studies, conducted principally in middle-aged men, suggest that exercise tolerance testing can provide independent prognostic information about the risk for future coronary heart disease events (relative risk with abnormal exercise tolerance testing, 2.0 to 5.0). However, when the risk for coronary heart disease events is low, most positive findings will be false and may result in unnecessary further testing or worry. The risk level at which the benefits of additional prognostic information outweigh the harms of false-positive results is unclear and requires further study. CONCLUSIONS Although screening exercise tolerance testing detects severe coronary artery obstruction in a small proportion of persons screened and can provide independent prognostic information about the risk for coronary heart disease events, the effect of this information on clinical management and disease outcomes in asymptomatic patients is unclear.