Cardiorespiratory Fitness and Risk of Heart Failure with Preserved Ejection Fraction

AIMS: Preventive strategies for heart failure with preserved ejection fraction (HFpEF) include pharmacotherapies and lifestyle modifications. However, the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized exercise treadmill test (ETT) and the risk of HFpEF has not been evaluated. Thus, we evaluated the association between CRF and HFpEF incidence. METHODS AND RESULTS: We assessed CRF in US Veterans (624 551 men; mean age 61.2 ± 9.7 years and 43 179 women; mean age 55.0 ± 8.9 years) by a standardized ETT performed between 1999 and 2020 across US Veterans Affairs Medical Centers. All had no evidence of heart failure or myocardial infarction prior to completion of the ETT. We assigned participants to one of five age- and gender-specific CRF categories (quintiles) based on peak metabolic equivalents (METs) achieved during the ETT and four categories based on CRF changes in those with two ETT evaluations (n = 139 434) ≥1.0 year apart. During a median follow-up of 10.1 years (interquartile range 6.0-14.3 years), providing 6 879 229 person-years, there were 16 493 HFpEF events with an average annual rate of 2.4 events per 1000 person-years. The adjusted risk of HFpEF decreased across CRF categories as CRF increased, independent of comorbidities. For fit individuals (≥10.5 METs) the hazard ratio (HR) was 0.48 (95% confidence interval [CI] 0.46-0.51) compared with least fit (≤4.9 METs; referent). Being unfit carried the highest risk (HR 2.88, 95% CI 2.67-3.11) of any other comorbidity. The risk of unfit individuals who became fit was 37% lower (HR 0.63, 95% CI 0.57-0.71), compared to those who remained unfit. CONCLUSIONS: Higher CRF levels are independently associated with lower HFpEF in a dose-response manner. Changes in CRF reflected proportional changes in HFpEF risk, suggesting that the HFpEF risk was modulated by CRF.