Abstract

Background Cardiorespiratory fitness (CRF) is a powerful predictor of mortality. This study evaluated the predictive value of CRF for mortality in Chilean subjects without atherosclerotic disease compared with the Framingham, European Systematic Coronary Risk Evaluation (SCORE), and 2013 ACC/AHA risk scores and determined the incremental predictive value of CRF when added to these scores. Hypothesis CRF improves prediction of all-cause and cardiovascular disease (CVD)-related mortality of the standard international risk scores. Methods Cross-sectional study, which evaluated 4064 subjects between 2002 and 2016. Cardiovascular (CV) risk factors, anthropometric and biochemical parameters, and blood pressure were measured. CRF was determined by metabolic equivalents during maximum stress test. The Framingham, SCORE, and ACC/AHA risk scores were calculated for all subjects. After a median follow-up of 9 years, all-cause and CVD-related mortality were assessed. Receiver operating curves were built to determine mortality prediction for CRF, the risk scores, and CRF added to the scores. Results As of August 2016, 99 deaths were reported, 33 of which were CVD-related. All risk scores and CRF predicted CVD-related mortality, with CRF identified as the best predictor: CRF: C = 0.88 (95% CI: 0.82-0.93) vs Framingham: C = 0.68 (95% CI: 0.60-0.76), SCORE: C = 0.76 (95% CI: 0.70-0.83), and ACC/AHA: C = 0.79 (95% CI: 0.73-0.85). Predictive power of the three scores improved when CRF was added to the model, but this was only significant for the Framingham score. Conclusions CRF is a good predictor of both, all-cause and CV mortality and a better predictor of CVD-related deaths than standard risk scores in this population.