Abstract 1058: Medical Management of Coronary Artery Disease: 12 Year Outcomes Stratified by Exercise Duration
Revascularization algorithms in chronic stable angina pectoris are complex, requiring the integration of multiple objective and subjective inputs. We aimed to assess whether the predictive value of exercise performance during symptom limited stress testing (ETT) in CAD patients is sustained in the long term and can be used for risk statification. Data derived from such extended follow-up would enable more accurate calculation of cost-effectiveness in comparative effectiveness studies. This prospective cohort study enrolled 693 men and women with proven CAD between 1992 and 2000 (mean age 67 years at entry, 82% men, 41% with history of MI). Management emphasized maximally tolerated medical therapy and modification of coronary risk factors. Subjects were exercised annually to symptom limit on a Bruce protocol rather than to target heart rate. ETT duration was an important element in the decision to refer for coronary angiography and revascularization in stable patients. There were 597 subjects with exercise data with a mean follow-up time of 12.3 years. In this group there were 240 deaths. Annualized all-cause mortality was 3.3%. In a time-varying Cox model, ETT duration was a highly significant predictor of outcome, along with age, diabetes and a history of heart failure. When ETT duration was stratified into 3 groups (>9 min, 6 –9 min, <6 min), annualized mortality rates were 1.5%, 2.8%, and 7.4% respectively. ETT duration is a persistent predictor of longterm outcomes which allows the identification of low risk patients in whom revascularization may be deferred. Symptom-limited duration instead of target heart rate appears to be useful for long-term risk stratification.