title: Racial Differences in the Prognostic Value of Cardiorespiratory Fitness (Results from the Henry Ford Exercise Testing Project).
abstract: 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, p <0.001) but had higher prevalence of hypertension (73% vs 57%, p <0.001) and obesity (28% vs 21%, p <0.001). On average, black patients achieved a lower CRF compared with whites (8.4 vs 9.5 metabolic equivalents, p <0.0001). A graded increase in mortality risk was noted with decreasing CRF for both black and white patients. In multivariate Cox regression, CRF was a predictor of both myocardial infarction and mortality, with no significant interaction between race, fitness, and outcomes (all interaction terms p >0.10). 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.
authors.affiliation: Division of Cardiovascular Medicine, Henry Ford Hospital, Detroit, Michigan; Department of Medicine, Wayne State University, Detroit, Michigan; King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, King ABdulAziz Cardiac Center, Ministry of National Guard, Health Affairs, Riyadh, Kingdom of Saudi Arabia. Electronic address: mouaz74@gmail.com.
authors.forename: Mouaz H
authors.initials: MH
authors.lastname: Al-Mallah
authors.affiliation: Wake Forest University School of Medicine, Winston Salem, North Carolina.
authors.forename: Waqas T
authors.initials: WT
authors.lastname: Qureshi
authors.affiliation: Division of Cardiovascular Medicine, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Keteyian
authors.affiliation: Division of Cardiovascular Medicine, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Clinton A
authors.initials: CA
authors.lastname: Brawner
authors.affiliation: Division of Cardiovascular Medicine, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Mohsin
authors.initials: M
authors.lastname: Alam
authors.affiliation: Johns Hopkins Ciccarone Center for Preventive Cardiology, Baltimore, Maryland.
authors.forename: Zeina
authors.initials: Z
authors.lastname: Dardari
authors.affiliation: Johns Hopkins Ciccarone Center for Preventive Cardiology, Baltimore, Maryland.
authors.forename: Khurram
authors.initials: K
authors.lastname: Nasir
authors.affiliation: Johns Hopkins Ciccarone Center for Preventive Cardiology, Baltimore, Maryland.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Blaha
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D015331:Cohort Studies; D005080:Exercise Test; D005260:Female; D006304:Health Status; D006801:Humans; D006973:Hypertension / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000208:ethnology* / Q000401:mortality; D009765:Obesity / Q000208:ethnology; D010809:Physical Fitness; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D044465:White People