Abstract 15439: Right Ventricular Area Indices Are Associated with Clinical Outcomes in Isolated Severe Functional Tricuspid Regurgitation

Abstract

Background: Severe functional tricuspid regurgitation (FTR) is associated with increased long-term morbidity and mortality, yet the optimal timing of intervention remains unknown. Identification of echocardiographic markers of adverse right ventricular (RV) remodeling may improve risk stratification and guide timing of intervention. Methods: We identified all consecutive outpatients with isolated severe FTR from our institutional echocardiography database (2002-2024), excluding patients with ≥ moderate left-sided valve disease, pulmonary hypertension or severe left ventricular systolic dysfunction. The primary endpoint was a composite of all cause death or first heart failure hospitalization (HFH) at 5 years. Associations between RV echocardiographic parameters and the primary endpoint were evaluated using multiple multivariable Cox regression models adjusted for age, chronic kidney disease, history of heart failure and left ventricle ejection fraction. RV to pulmonary artery coupling was assessed using RV free wall strain to systolic pulmonary artery pressure ratio (RVFWA/SPAP). Results: The study included 438 patients (age 75.5 ± 12.3, 42% male). Over a median follow-up of 31.3 (14.8 - 60) months, 175 patients (40%) experienced the primary endpoint of death or HFH. After adjustment for clinical risk factors, RV end-diastolic area index (RVEDAi), RV end-systolic area index (RVESAi), right atrial area (RAA) and RVFWS/SPAP remained independently associated the primary outcome, while no significant association was found for SPAP, tricuspid annular plane systolic excursion (TAPSE), RV S′, and TAPSE/SPAP or RV linear dimensions. In models additionally incorporating RAA and RVFWS/SPAP, RVEDAi and RVESAi remained independently associated with death or HFH (RVEDAi: HR 1.085 per cm 2 /m 2 , CI: 1.016 - 1.159, p=0.016; RVESAi: HR 1.134 per cm 2 /m 2 , CI: 1.035 - 1.242, p=0.007), whereas RVFWS/SPAP and RAA did not. Dilated RVEDAi and RVESAi were the strongest independent predictors of outcomes (RVEDAi ≥ 14 cm 2 /m 2 HR 1.609, CI: 1.106 - 2.342, p=0.013; RVESAi ≥ 8 cm 2 /m 2 : HR 1.562 CI: 1.084 - 2.251, p=0.017). Conclusions: In patients with isolated severe FTR, RVEDAi and RVESAi are independently associated with adverse outcomes. Progressive RV enlargement is associated with increasing risk, suggesting a potential role for RV area indices in risk stratification and timing of intervention.