Determinants of Right Ventricular Dysfunction in Pulmonary Arterial Hypertension: Beyond Pulmonary Vascular Resistance

Abstract

Purpose Right ventricular dysfunction (RVD) is associated with adverse outcomes in pulmonary arterial hypertension (PAH). Determinants of RVD in PAH patients beyond pulmonary vascular resistance (PVR) have not been well defined. Methods We conducted a case-control study including PAH patients at our center with and without RVD based on cardiac MRI-derived RV ejection fraction (RVEF) Results 36 subjects (mean age 55±13 years, 75% female) were included. Both RVD and no-RVD patients had similar PVR (502±225 vs 506±228 dynes-sec/cm5, p=0.95), mean pulmonary artery pressure (PAP) (44±11 vs 42±14 mm Hg, p=0.52) and cardiac index (3.0±0.9 vs 3.0±0.5 L/min/m2, p=0.81) but RVD patients had larger RV size (RV end diastolic volume index 131±37 vs 94±28 ml/m2, p= Conclusion In a PAH patient cohort matched for PVR, left ventricular size, LVEF and male gender were associated with RVD. These findings underscore the importance of left ventricular dynamics and ventricular interdependence in the physiology of RVD in PAH.