Ventricular-Arterial Coupling and Exercise-Induced Pulmonary Hypertension During Low-Level Exercise in Heart Failure With Preserved or Reduced Ejection Fraction

Background Exercise-induced pulmonary hypertension (EIPH) may develop even at low workloads in heart failure (HF) patients. Ventricular-arterial stiffening plays an important role in the pathophysiology of HF with preserved ejection fraction (HFpEF). This study aimed to compare the response of ventricular-arterial coupling and PH during low-level exercise between HFpEF and HF with reduced EF (HFrEF). Methods and Results Echocardiography was performed at rest and during 10 W of bicycle exercise in HFpEF (n = 37) and HFrEF (n = 43). Load-independent contractility (end-systolic elastance [Ees], preload recruitable stroke work [PRSW], and peak power index [PWRI]), arterial afterload (arterial elastance [Ea]), and ventricular-arterial interaction (Ea/Ees) were measured with the use of a noninvasive single-beat technique. EIPH was defined as an estimated pulmonary arterial systolic pressure (PASP) of ≥50 mm Hg at 10 W of exercise. PASP was significantly increased during 10 W of exercise in both HF types, and ~50% of HFpEF patients developed EIPH. Arterial afterload was increased significantly during exercise in both groups. HFrEF and HFpEF patients showed a significant increase in LV contractility assessed by Ees, PRSW, and PWRI during exercise. Although Ea/Ees ratio decreased significantly in HFrEF, reduction in Ea/Ees was attenuated because of blunted Ees increases in patients with HFpEF compared with HFrEF. Conclusions Even at low-level exercise, ~50% of HFpEF patients developed EIPH. Reduction in Ea/Ees was attenuated owing to less Ees increase in HFpEF compared with HFrEF. Further studies are needed to elucidate the association between ventricular-arterial coupling and EIPH in HFpEF.