Abstract 20173: Effects of Pulmonary Vasodilator Therapy on Hemodynamics and Exercise Capacity in Patients With Exercise Induced Pulmonary Hypertension Due to Pulmonary Vascular Disease or Heart Failure With Preserved Ejection Fraction
Background: Both exercise induced pulmonary arterial hypertension (EIPAH) and early heart failure with preserved ejection fraction (HFpEF) can manifest as exercise induced PH. During exercise testing, failure of the pulmonary vascular resistance (PVR) to decrease or widening of the TPG during exercise may also indicate HF with disproportionate PH (HFpEF+PH). The effects of pulmonary vasodilator therapies in EIPAH and HFpEF+PH are uncertain.
Methods: Patients with resting PAH (n=8), EIPAH (n=11), and HFpEF+PH (n=8) underwent exercise right heart catheterization (RHC) on a supine bicycle ergometer. After treatment with PDE-5 inhibitors and endothelin receptor antagonists, patients were restudied with exercise RHC. Maximum workload achieved between initial and follow-up studies was compared using Fisher’s exact test. PVR index (PVRI) and cardiac index (CI) were compared using paired sample analyses.
Results: Mean time between initial and repeat exercise RHC was 15 months (range 3 to 51 months). Whereas workload achieved (watts) significantly increased in EIPAH patients (p=0.049) and slightly increased in resting PAH patients (p=0.179) on repeat testing, workload achieved in HFpEF+PH patients was unchanged (p=1.0). PVRI (Wood units•m2) at max exercise was improved in patients with EIPAH (4.9 to 3.8, p=0.019) and resting PAH (5.4 to 4.4, p=0.004) but unchanged in HFpEF+PH (4.4 to 4.4, p=0.997). CI (L/min/m2) at max exercise tended to improve in the EIPAH group (6.1 to 6.8, p=0.074) but was unchanged in both the HFpEF+PH (5.3 to 5.5, p=0.519) and resting PAH (5.4 to 5.5, p=0.312) groups.
Conclusion: Pulmonary vasodilators improved functional capacity and hemodynamics in EIPAH patients but not in HFpEF+PH patients. Even in exercise induced PH primarily due to HFpEF with disproportionate PH, the benefits of pulmonary vasodilator therapy remains unproven. Better mechanistic understanding of disproprotionate PH in HFpEF as well as characterization of this patient group is necessary.
Author Disclosures: D.C. Ishizawar: None. M. Lander: None. M.A. Mathier: None.
- © 2014 by American Heart Association, Inc.