Exercise capacity and mortality among men referred for exercise testing.
Level 3 - non-randomized controlled study
Non-randomized clinical cohort follow-up study.
PubMed 11893790 · doi:10.1056/NEJMoa011858
What was done
A total of 6,213 consecutive men referred for clinical treadmill exercise testing were followed for a mean (±SD) of 6.2±3.7 years. Participants were grouped into those with an abnormal exercise test or cardiovascular disease history (n=3,679) and those with a normal test and no cardiovascular disease history (n=2,534). The primary endpoint was overall mortality.
What was found
There were 1,256 deaths during follow-up (annual mortality 2.6%). After adjustment for age, peak exercise capacity in metabolic equivalents (MET) was the strongest predictor of mortality in both normal participants and those with cardiovascular disease. Each 1-MET increase in exercise capacity was associated with a 12% improvement in survival. Absolute peak exercise capacity was a stronger predictor than percentage of age-predicted value, and beta-blocker use did not alter this relationship.
Why it matters
The study shows that measured exercise capacity is a more powerful predictor of mortality than traditional clinical risk factors in men referred for testing, regardless of baseline cardiovascular status.
Limits
The cohort included only men referred for clinical testing, limiting generalizability to women and unselected community populations. The abstract does not report cause-specific mortality or full multivariable adjustment beyond age.
Cited by
- supports Having low cardiorespiratory fitness in the absence of other chronic diseases is as strong or stronger a predictor of all-cause mortality than cardiovascular disease, hypertension, or smoking.