Abstract P172: Exercise Hemodynamics of Heart Failure with Preserved Ejection Fraction: a Meta-Analysis

Abstract

Background: Heart failure with preserved ejection fraction (HFpEF) is associated with increased morbidity and mortality, and recalcitrant to available medical therapies. A major challenge in development of effective therapies for HFpEF is the heterogeneity in the underlying pathophysiological mechanisms, with numerous studies demonstrating conflicting findings. We conducted a meta-analysis to characterize the underlying exercise hemodynamic abnormalities that define HFpEF. Methods: 15 studies comparing hemodynamic parameters between HFpEF and normal or hypertensive controls were pooled. Standardized mean differences (SMD) in the exercise reserve (peak exercise - resting) measures of hemodynamic parameters between the HFpEF and control group were pooled using a random-effects model meta-analysis. Results: The meta-analysis included 627 HFpEF patients (age range: 57 - 74 years, 66% women, 80% with hypertension) and 365 normal controls (age range: 47 - 72 years, 58% women, 50% with hypertension). In pooled analysis, HFpEF patients had significantly lower peak oxygen uptake [SMD (95% CI): -1.8 (-1.9 to -1.6)]. HFpEF patients had significantly lower cardiac index (CI)[SMD (95% CI): -2.1 (-2.3 to -1.9)], heart rate (HR) [SMD (95% CI): -1.3 (-1.5 to -1.1)], stroke volume index (SVI)[SMD (95% CI): -0.78 (-0.94 to -0.61)] and arterio-venous oxygen difference (a-VO 2 Diff) reserve [SMD (95% CI): -0.68 (-0.91 to -0.44)]. HFpEF patients also had significantly greater increase in left ventricular filling (LV) pressure [SMD (95% CI): 2.03 (1.76 to 2.3)] and systemic vascular resistance (SVR) [SMD (95% CI): 1.20(0.94 to 1.45)] despite no change in LV end-diastolic volume reserve between groups. Conclusion: HFpEF patients have significantly reduced exercise capacity secondary to impaired central (decreased CI, SVI, HR reserve, and increased LV filling pressures without a change in LV diastolic reserve) and peripheral abnormalities (increased SVR and decreased a-VO 2 Diff).