Racial Differences in the Prognostic Value of Cardiorespiratory Fitness (Results from the Henry Ford Exercise Testing Project)

The aim of this analysis was to determine whether racial differences exist in the prognostic value of cardiorespiratory fitness (CRF) in black and white patients undergoing stress testing. We included 53,876 patients (mean age 53 ± 13, 49% women) from the Henry Ford Exercise Testing project free of established coronary disease or heart failure who completed a maximal exercise test from 1991 to 2009. Patients were followed for a mean duration of 11.5 years for all-cause mortality, ascertained by linkage with the Death Master File. Follow-up over mean 6.2 years was also available for incident myocardial infarction. Multivariate Cox proportional hazards regression models were used adjusting for demographic variables, risk factors, medications, and reason for stress test referral, including formal interaction testing by race (black vs white). Black patients (n = 16,725) were younger (54 ± 13 vs 52 ± 13, p0.10). CRF is a strong predictor of all-cause mortality in both white and black patients, with no significant interaction observed between race, fitness, and outcomes.