Abstract 13499: Unravelling the Pathophysiology of Right Ventricular Maladaptive Hypertrophy in Chronic Pulmonary Hypertension Through Imaging and Omics

Introduction: Right ventricular (RV) failure is the strongest determinant of survival in chronic pulmonary hypertension (PH), but its pathophysiological mechanisms remain unclear. Hypothesis: In addition to RV pressure overload, compounds liberated from the pulmonary vascular damage (identifiable by omics) may exert a detrimental effect on RV function in PH. Methods: Four different experimental models of RV pressure overload in 48 Yucatan pigs were developed: chronic postcapillary PH by pulmonary veins banding (M1); chronic PH by aorto-pulmonary shunting (M2); RV pressure overload by PA banding (thus without PH) (M3); and sham procedure (M0). Animals were evaluated at 1, 5 and 8 months after surgery by right heart catheterization, cardiac magnetic resonance (CMR), and blood/histological sampling. Unsupervised proteomic and metabolomic analyses were performed and compared among experimental groups and to the severity of RV dysfunction. Results: A total of 33 pigs completed follow-up (M1,n=8; M2,n=6; M3,n=10; and M0,n=9). As expected, M1&M2-animals developed chronic PH, whereas M3-animals had severely increased RV systolic pressure without PH (Table). M3-pigs developed more severe RV hypertrophy (significantly higher mass on CMR and cardiomyocyte area on histology), but maintained normal function. In contrast, M1&M2 animals developed RV systolic disfunction and increased myocardial apoptosis in M1. Plasma metabolomic and proteomic patterns differed among groups, highlighting greater inflammation and taurine/arginine deficiency in PH models (M1&M2), coagulation disturbances in M1, and predominant lipidomic changes in M3. Key proteins/metabolites from coagulation, complement system and apolipoproteins pathways significantly associated with RV performance. Conclusion: Maladaptive RV hypertrophy in PH is associated with significant changes in plasma proteins and metabolites. Their identification may help to identify potential targets.