Functional volume distribution in tricuspid regurgitation associated right heart failure

Abstract

Abstract Background Tricuspid regurgitation (TR) associated right heart failure is a significant challenge, and while tricuspid edge-to-edge repair (TEER) has been suggested to improve outcomes, patients remain at substantial residual risk. Thus, adjunctive therapies to treat associated right heart failure are warranted. Sympathetically mediated venoconstriction with subsequent changes in functional volume distribution with increases in stressed blood volume (SBV) ( the volume compartment which generates intravascular pressure) has been shown to importantly mediate hemodynamic derangements in heart failure and might pose an attractive adjunctive treatment target (e.g. by means of splanchnic denervation). Objectives This study aimed to elucidate the determinants of unfavorable functional volume distribution in patients with TR-associated right heart failure and investigate the prognostic role of SBV after TEER. Methods and Results A total of 279 patients underwent right heart catheterization (RHC) prior to TEER. SBV was estimated (eSBV) from hemodynamic variables fit to an extensively validated and comprehensive cardiovascular model. eSBV was associated with obesity, renal and hepatic dysfunction, and cardiac remodeling (p < 0.05 for all). Hemodynamically, eSBV correlated with pulmonary artery (PA) and cardiac filling pressures, as well as right ventricular-PA coupling (p < 0.05 for all). After TEER, patients with eSBV above the median demonstrated less reduction in right atrial pressures, peripheral edema, and ascites compared to lower eSBV patients (p < 0.05 for all). Higher eSBV was a powerful predictor of the occurrence of death and heart failure hospitalization during a median follow-up of 618 days (p < 0.05 for all) independent of all clinical, imaging, and invasive hemodynamic parameters. Conclusion In severe TR, eSBV is associated with obesity, renal and liver dysfunction, more severe heart failure, attenuated reduction of venous congestion after TEER, as well as adverse clinical outcomes. Estimation of SBV should be incorporated in future trials in the field to identify patients in need of adjunctive therapies and test its role as a potential treatment target.