Pulmonary Hypertension in Adults With a Systemic Right Ventricle (Biventricular Circulation)

Background: Little is known regarding pulmonary hypertension (PH) in adults with a systemic right ventricle. Objectives: This study evaluates the hemodynamic profile of PH in patients with transposition of great arteries palliated with an atrial switch repair (TGA-AS) and congenitally corrected TGA (CCTGA). Methods: This was a retrospective cohort study of adults with TGA-AS or CCTGA who had undergone invasive hemodynamic assessment. Exclusion criteria were single ventricle anatomy, previous Rastelli, arterial switch, or double switch operation. PH was defined by a mean pulmonary artery pressure (mPAP) >20 mm Hg and subtypes according to 2022 European Society of Cardiology guidelines. The primary combined clinical endpoint was death, heart transplantation, or need for mechanical circulatory support. Results: A total of 261 patients were studied (TGA-AS, n = 161 and CCTGA, n = 100). PH prevalence was similar in both groups (65% vs 69%, P = 0.74). PH subtype was precapillary in 24%, isolated postcapillary (IpcPH) 25%, combined postcapillary and precapillary 51% (similar in both groups). The relationship between pulmonary capillary wedge pressure and mPAP was overall similar between 2 groups but there was greater variability in pulmonary capillary wedge pressure once mPAP >40 mm Hg in the TGA-AS group. The incidence of the primary endpoint was similar in both groups (24 v 29%; P = 0.39). Factors associated with the primary clinical endpoint were elevated PVR (in particular, in the TGA-AS subgroup) and lower aortic pulsatility index (both groups). Conclusions: In this large study evaluating the hemodynamic phenotype in patients with a systemic RV referred for catheterization, PH was common and most commonly the combined postcapillary and precapillary subtype.