ABSTRACT

Introduction Screening is a universally accepted populationbased strategy to reduce disease burden related to breast and colon cancer.1 Given the greater incidence of cardiovascular disease, it would seem logical that screening for this ailment would be uniformly supported due to the potential individual and societal benefits of early intervention. Nonetheless, screening for cardiovascular disease remains an area of strong debate that has elicited much controversy and produced many discordant research results. Nearly two decades ago, research was undertaken to examine the prognostic utility of exercise electrocardiography (EKG) to screen asymptomatic subjects, including individuals at high risk.1,2 The evidence collected at that time did not support the use of exercise treadmill testing to screen for occult coronary artery disease (CAD) in individuals without angina-like symptoms.2 In fact, in a review by Goldman et al2 the evidence for the utility of exercise-induced ST-segment changes on the EKG was reported as being overwhelmingly negative. The authors concluded that it would be highly cost-ineffective to screen asymptomatic individuals: about $2 million per life-year saved which is far in excess of the threshold for economic efficiency of $50 000 per life-year saved set by the US Public Health Service.2-4 However, recent evidence has evaluated more than the predictive value of the EKG changes and has established that measurements of functional capacity during exercise treadmill are good estimators of long-term risk in high-risk asymptomatic individuals.5,6

In addition to other reports evaluating the predictive value of stress testing with imaging, these advances have been instrumental in reshaping our thoughts about the value of screening in asymptomatic individuals – and specifically the value of screening for subclinical atherosclerotic disease markers. In both the USA and Europe, there has been mounting interest in screening for cardiovascular disease due to the very significant economic and health-related burden of this disease for Western societies.1,7-15 In large part, the interest has been supported by a realization that our traditional approaches to risk assessment result in a substantial detection gap.15,16 Furthermore, the current risk assessment methods based on risk factor categories fail to account for a sizeable proportion of explanatory variation in outcome.12,15 This means that for many patients, the risk will be underestimated and their ensuing treatment patterns will be less aggressive, resulting in suboptimal risk reduction strategies.