Exercise capacity and mortality among men referred for exercise testing.
BACKGROUND
Exercise capacity is known to be an important prognostic factor in patients with cardiovascular disease, but it is uncertain whether it predicts mortality equally well among healthy persons. There is also uncertainty regarding the predictive power of exercise capacity relative to other clinical and exercise-test variables.


METHODS
We studied a total of 6213 consecutive men referred for treadmill exercise testing for clinical reasons during a mean (+/-SD) of 6.2+/-3.7 years of follow-up. Subjects were classified into two groups: 3679 had an abnormal exercise-test result or a history of cardiovascular disease, or both, and 2534 had a normal exercise-test result and no history of cardiovascular disease. Overall mortality was the end point.


RESULTS
There were a total of 1256 deaths during the follow-up period, resulting in an average annual mortality of 2.6 percent. Men who died were older than those who survived and had a lower maximal heart rate, lower maximal systolic and diastolic blood pressure, and lower exercise capacity. After adjustment for age, the peak exercise capacity measured in metabolic equivalents (MET) was the strongest predictor of the risk of death among both normal subjects and those with cardiovascular disease. Absolute peak exercise capacity was a stronger predictor of the risk of death than the percentage of the age-predicted value achieved, and there was no interaction between the use or nonuse of beta-blockade and the predictive power of exercise capacity. Each 1-MET increase in exercise capacity conferred a 12 percent improvement in survival.


CONCLUSIONS
Exercise capacity is a more powerful predictor of mortality among men than other established risk factors for cardiovascular disease.
Myers
Jonathan
J
Division of Cardiovascular Medicine, Stanford University Medical Center and the Veterans Affairs Palo Alto Health Care System, Palo Alto, Calif CA 94304, USA. drj993@aol.com
Prakash
Manish
M
Froelicher
Victor
V
Do
Dat
D
Partington
Sara
S
Atwood
J Edwin
JE
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000401:mortality / Q000503:physiopathology; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D012306:Risk; D012307:Risk Factors; D016019:Survival Analysis
D000319:Adrenergic beta-Antagonists