Prediction of long-term prognosis in 12 169 men referred for cardiac rehabilitation.
BACKGROUND
Predicting the risk of cardiac and all-cause death in patients with established coronary heart disease is important in counseling the individual and designing risk-stratified rehabilitation and secondary prevention programs. Cox proportional hazards and Kaplan-Meier survival curves were thus completed on initial assessment data obtained from patients referred to an outpatient cardiac rehabilitation center.


RESULTS
A single-center prospective observational design took peak cardiorespiratory exercise test data for 12 169 male rehabilitation candidates aged 55.0+/-9.6 years (7096 myocardial infarctions [MIs], 3077 coronary artery bypass grafts [CABGs], and 1996 documented cases of ischemic heart disease [IHD]). A follow-up of 4 to 29 years (median, 7.9) yielded 107 698 man-years of experience. Entry data were tested for associations with time to cardiac and all-cause death. We recorded 1336 cardiac deaths (953 MI, 225 CABG, and 158 IHD) and 2352 all-cause deaths. A powerful predictor of cardiac and all-cause mortality was measured peak oxygen intake (VO2peak). For the overall sample, values of <15, 15 to 22, and >22 mL/kg per minute yielded respective multivariate adjusted hazard ratios of 1.00, 0.62, and 0.39 for cardiac and 1.00, 0.66, and 0.45 for all-cause deaths. For the separate diagnostic categories, apart from VO2peak, the only other significant predictors of cardiac death common to all 3 were smoking and digoxin, and for all-cause death, age, smoking, digoxin, and diabetes.


CONCLUSIONS
Exercise capacity, as determined by direct measurement of VO2peak, exerts a major long-term influence on prognosis in men after MI, CABG, or IHD and can play a valuable role in risk stratification and counseling.
Kavanagh
Terence
T
Toronto Rehabilitation Institute, University of Toronto, Ontario, Canada. terence.kavanagh@utoronto.ca
Mertens
Donald J
DJ
Hamm
Larry F
LF
Beyene
Joseph
J
Kennedy
Johanna
J
Corey
Paul
P
Shephard
Roy J
RJ
D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000175:diagnosis / Q000401:mortality* / Q000534:rehabilitation*; D005080:Exercise Test; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000534:rehabilitation; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000401:mortality / Q000534:rehabilitation; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D015996:Survival Rate