Abstract 17098: Racial Differences in the Prognostic Value of Exercise Capacity: An Analysis of 52,515 Consecutive Patients From the FIT Project
Background: The purpose of this study was to investigate whether differences exist in the prognostic value of exercise capacity between African-Americans (AA) and Caucasians (CA) in predicting all cause mortality.
METHODS: We included 52,515 AA and CA patients without known coronary disease or heart failure who completed a routine clinical exercise test with or without imaging for diagnostic or screening purposes in a clinical non-invasive laboratory between 1991 and 2009. Patients were followed for a mean duration of 11.5 years for all-cause mortality ascertained by a search of social security death index in 4/2013. Cox proportional hazards regression models were used adjusting for age, gender, weight, smoking, history of HTN, DM, HLD, obesity, family history of CV disease, use of aspirin, anti hypertensives, lipid lowering and diabetes medications, reason referred for a stress test and beta blocker use.
RESULTS: AA patients (n=16,516) were younger (54 vs. 52 years, p<0.001), but had higher prevalence of hypertension (72% vs. 57%, p<0.001) and diabetes (24% vs. 15%, p<0.001). On average, AA achieved less METS compared to CA (8.5 vs. 9.5 METS, p<0.0001). A graded increase in mortality risk was noted with decreased exercise capacity for both AA and CA patients (table). In multivariable Cox regression, there was a significant interaction between race and METs (P =0.011). An increase in exercise capacity of one MET was associated with 16% (95% CI 15%-17%) reduction in all-cause mortality in CA, compared to 24% reduction in AA (95% CI 23-25%).
CONCLUSIONS: Exercise capacity is a strong predictor of all-cause mortality in both AA and CA; however, a significant interaction exists. Using data from the FIT project, African American patients appear to obtain a greater survival benefit from increasing exercise capacity.
- © 2013 by American Heart Association, Inc.