Heart failure with preserved ejection fraction incidence in hypertensive patients according to cardiorespiratory fitness

Introduction Heart failure (HF) with preserved ejection fraction (HFpEF) is closely associated with traditional cardiac risk factors including hypertension. Strategies to prevent the incidence of HFpEF include lifestyle modifications. However, the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized exercise treadmill test (ETT) and HFpEF incidence in hypertensive patients has not been evaluated. Purpose Evaluated the association between CRF and HFpEF incidence in hypertensive patients. Method We assessed CRF in 390,880 hypertensive patients (mean age 62.7 ± 8.6 years by a standardized exercise treadmill test (ETT) performed across US Veterans Affairs Medical Centers. All had no evidence of HF or myocardial infarction prior to completion of the ETT. We established five age-and-gender-specific CRF categories (quintiles) based on peak metabolic equivalents (METs) achieved during the ETT. Q1 (n=80,569; METs=4.6±1.2); Q2 (n=101,358; METs=7.0±1.1): Q3 (n=77,649; METs=8.4±1.2); Q4 (n=97,624; METs=10.3±0.9); Q5 (n=33,680; METs=13.2±1.5) Results During 5,471,090 person-years of follow-up (median 14.0 years), there were 16,493 HFpEF events with an average annual rate of 2.4 events per 1,000 person-years. The adjusted risk of HFpEF decreased progressively across CRF categories as CRF increased, independent of comorbidities. Compared to Q1 (Referent; 4.6±1.2 METs), the risk was 27% lower (hazard ratio [HR] 0.73, 95% CI 0.69-0.75) for individuals within Q2 (7.0 ±1.1 METs) and 61% lower (HR 0.39, 95% CI 0.36-0.43) for those in Q5. Being unfit carried the highest risk (HR, 2.22; 95% CI, 2.33-2.80) of any other comorbidity. Similar findings were observed for those <65.0 and ≥65 years. Conclusions Higher CRF levels were independently associated with lower HRpEF incidence in a dose-response manner in hypertensive patients. The lower risk was observed at relatively low CRF levels (7.0 METs) achievable by most middle-aged and older individuals by engaging in approximately 25-30 minutes of brisk walk daily.