Cardiorespiratory Fitness Improves the Accuracy of Atherosclerotic Cardiovascular Disease Pooled Cohort Risk Model

Background: The Pooled Cohort risk equations are used for atherosclerotic cardiovascular disease (ASCVD) risk stratification. The purpose of the current study was to evaluate whether cardiorespiratory fitness could be used to improve the accuracy of the risk model.

Methods: We evaluated 15,596 asymptomatic self-referred adults aged 40-79 years who were screened annually at a tertiary medical center in Israel. All subjects were free of cardiovascular disease at baseline and completed maximal exercise stress test according to the Bruce protocol. The ASCVD risk score was calculated for all subjects. The primary end point was the composite of death, non-fatal myocardial infarction and stroke, after excluding subjects diagnosed with metastatic cancer during follow up. Baseline cardiorespiratory fitness was dichotomized into two groups: low (metabolic equivalents [METs] < 11) and high.

Results: Mean age of study population was 51±8 years and 72% were men. During median follow up of 8 years (Interquartile range 3-13) 1,412 (9%) subjects developed the study end point. Kaplan-Mayer survival analysis showed that both ASCVD risk score and low fitness were independently associated with developing of the study endpoint (p

Conclusions: Low cardiorespiratory fitness is a strong independent predictor of the cardiovascular morbidity and mortality in asymptomatic adults. Addition of fitness to the pooled cohort ASCVD risk significantly improves the accuracy of the model.