Global risk scores and exercise testing for predicting all-cause mortality in a preventive medicine program

Context The usefulness of exercise stress test results and global cardiovascular risk systems for predicting all-cause mortality in asymptomatic individuals seen in clinical settings is unclear. Objectives To determine the validity for prediction of all-cause mortality of the Framingham Risk Score and of a recently described European global scoring system Systematic Coronary Risk Evaluation (SCORE) for cardiovascular mortality among asymptomatic individuals evaluated in a clinical setting and to determine the potential prognostic value of exercise stress testing once these baseline risks are known. Design, Setting, and Participants Prospective cohort study of 3554 asymptomatic adults between the ages of 50 and 75 years who underwent exercise stress testing as part of an executive health program between October 1990 and December 2002; participants were followed up for a mean of 8 years. Main Outcome Measures Global risk based on the Framingham Risk Score and the European SCORE. Prospectively recorded exercise stress test result abnormalities included impaired physical fitness, abnormal heart rate recovery, ventricular ectopy, and ST-segment abnormalities. The primary end point was all-cause mortality. Results There were 114 deaths. The c-index, which corresponds to receiver operating characteristic curve values, and the Akaike Information Criteria found that the European SCORE was superior to the Framingham Risk Score in estimating global mortality risk. In a multivariable model, independent predictors of death were a higher SCORE (for 1% predicted increase in absolute risk, relative risk [RR], 1.07; 95% confidence interval [CI], 1.04-1.09; P<.001), impaired functional capacity (RR, 2.95; 95% Cl, 1.98-4.39; P<.001), and an abnormal heart rate recovery (RR, 1.59; 95%, 1.04-2.41; P=.03). ST-segment depression did not predict mortality. Among patients in the highest tertile from the SCORE, an abnormal exercise stress test result, defined as either impaired functional capacity or an abnormal heart rate recovery, identified a mortality risk of more than 1% per year. Conclusion Exercise stress testing when combined with the European global risk SCORE may be useful for stratifying risk in asymptomtic individuals in a comprehensive executive health screening program.