Pulmonary Vascular Resistance During Exercise Predicts Long-Term Outcomes in Heart Failure With Preserved Ejection Fraction

Background: In heart failure with preserved ejection fraction (HFpEF), the prognostic value of pulmonary vascular dysfunction (PV-dysfunction), identified by elevated pulmonary vascular resistance (PVR) at peak exercise, is not completely understood. We evaluated the long-term prognostic implications of PV-dysfunction in HFpEF during exercise in consecutive patients undergoing invasive cardiopulmonary exercise testing for unexplained dyspnea. Methods: Patients with HFpEF were classified into 2 main groups: resting HFpEF (n = 104, 62% female, age 61 years) with a pulmonary arterial wedge pressure (PAWP) >15 mmHg at rest; and exercise HFpEF (eHFpEF; n = 81) with a PAWP <15 mmHg at rest, but >20 mmHg during exercise. The eHFpEF group was further subdivided into eHFpEF + PV-dysfunction (peak PVR 80 dynes/s/cm(-5); n = 55, 60% female, age 64) group and eHFpEF PV-dysfunction (peak PVR <80 dynes/s/cm(-5); n = 26, 42% female, age 54 years) group. Outcomes were analyzed for the first 9 years of follow-up and included any cause mortality and heart failure (HF)-related hospitalizations. The mean follow-up time was 6.7 +/- 2.6 years (0.5-9.0). Results: Mortality rate did not differ among the groups. However, survival free of HF-related hospitalization was lower for the eHFpEF + PV-dysfunction group compared with eHFpEF PV-dysfunction (P = .01). These findings were similar between eHFpEF + PV-dysfunction and the resting HFpEF group (P = .774). By Cox analysis, peak PVR >= 80 dynes/s/cm(-5) was a predictor of HF-related hospitalization for eHFpEF (hazard ratio 5.73, 95% confidence interval 1.05-31.22, P = .01). In conclusion, the present study provides insight into the impact of PV-dysfunction on outcomes of patients with exercise-induced HFpEF. An elevated peak PVR is associated with a high risk of HF-related hospitalization.