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.
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.
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% CI, 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.
Exercise stress testing when combined with the European global risk
SCORE may be useful for stratifying risk in asymptomatic individuals in a
comprehensive executive health screening program.