Exercise Capacity and Mortality among Men Referred for Exercise Testing

TLDR

Exercise capacity is a known prognostic factor in cardiovascular disease, but its predictive value for mortality in healthy individuals remains uncertain. This study aimed to assess whether exercise capacity predicts mortality better than other clinical and exercise‑test variables in men undergoing treadmill testing. We followed 6,213 men, classifying them as abnormal or normal exercise‑test groups, and recorded all deaths over an average 6.2‑year follow‑up. Peak exercise capacity in metabolic equivalents was the strongest mortality predictor, with each 1‑MET increase improving survival by 12 %, outperforming other risk factors and remaining robust regardless of beta‑blocker use.

Abstract

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.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.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.Exercise capacity is a more powerful predictor of mortality among men than other established risk factors for cardiovascular disease.