Abstract
Background
Exercise capacity, as measured by metabolic equivalents of task [METs], varies with gender and is an independent predictor of mortality. We sought to investigate gender differences in the protocol selected, the estimated exercise capacity, and the prognostic value of METs.
Purpose
Investigate the gender differences in the protocol chosen (adjusting for age and comorbidities), the METs achieved (also adjusting for the protocol selected), and the predictive value of exercise capacity adjusted to METs achieved.
Methods
In a 25-year stress testing registry spanning from 1991 to 2015, we identified 120,705 patients who underwent exercise stress testing. Protocols were split into Bruce vs. non-Bruce. METs were estimated based on established gender-specific formulas (the St James Take Heart Project formula for women, and the Veterans Affairs cohort formula for men).The primary outcome was all-cause mortality.
Results
The mean age was 53.3±12.5 years, and 59% were male. Table 1 presents the baseline characteristics and exercise parameters. A total of 8426 death occurred over 8.7 years of mean follow-up duration. Females were more commonly referred for non-Bruce protocols [adjusted OR 2.6; 95% CI (2.5–2.7)] even after adjusting for age and comorbidities. Within the same protocol chosen, females achieved lower estimated METs [Beta −1.4; 95% CI (−1.43 to −1.37)]. Exercise capacity was inversely related to mortality in both genders and across protocols (figure 1), however, after adjusting for age, comorbidities, protocol chosen, and the number of METs achieved, the HR for death was significantly lower for women [adjusted HR=0.44; 95% CI (0.41–0.46)].
Conclusion
After adjusting for age and comorbidities, women tend to be more commonly referred for non-Bruce protocols, achieve less estimated METs (after adjusting for the protocol chosen), and have half the mortality for the same METs achieved.
Death vs. Exercise capacity by gender
Funding Acknowledgement
Type of funding source: None
3136Incremental and synergistic prognostic value of exercise stress testing and standard risk factor assessment in asymptomatic executives: a primary prevention study
