Exercise capacity and mortality - a follow-up study of 3033 subjects referred to clinical exercise testing

Abstract

Background: Exercise stress testing is used as a diagnostic and prognostic tool. We determined the prognostic significance of exercise test findings for cardiovascular (CVD) and all-cause mortality in men and women.

Material and methods: 3033 subjects underwent a symptom-limited bicycle exercise test. Exercise capacity was defined as the mean of last four minutes of exercise workload.

Results: During an average follow-up of 19 years, 186 (11.6%) CVD and 370 (20.6%) all-cause deaths in men and 57 (5.0%) CVD and 155 (12.5%) all-cause deaths in women occurred. Among exercise test variables (workload, ECG, BP, HR), exercise capacity was the strongest predictor of mortality. Low exercise capacity (1st quartile) was associated with a hazard ratio of 4.2 (95% CI: 1.7, 10.8) for CVD and 4.0 (95% CI: 2.5, 6.4) for all-cause mortality compared with high exercise capacity (4th quartile) among men and in women with a 5.4-fold (95% CI: 1.2, 24.0) risk for CVD and 2.3-fold (95% CI: 1.2, 4.3) risk for all-cause mortality, respectively. The relationship between other exercise test variables and mortality was much weaker.

Conclusions: Among exercise test variables exercise capacity was the strongest predictor of CVD and all-cause mortality in both genders, and especially CVD deaths in women. Key Messages Exercise capacity was the most powerful predictor of CVD and all-cause mortality in both men and women. Low exercise capacity is a strong predictor of CVD death, especially among women.

Keywords: Exercise; exercise test; men; mortality; physical fitness; prevention & control; women.