Abstract
BACKGROUND: Assessing right ventricular (RV) function is paramount for risk stratification, which remains challenging in patients with tricuspid regurgitation (TR). We assessed RV-pulmonary artery (PA) coupling and its predictability of outcomes after transcatheter tricuspid valve repair (TTVR). METHODS: Study participants comprised patients undergoing transcatheter tricuspid valve repair to treat symptomatic TR from June 2015 to July 2021. We calculated an RV-PA coupling ratio using a formula, which is dividing tricuspid annular plane systolic excursion (TAPSE) by echocardiographically estimated (ePASP) or invasively measured PASP (iPASP) at baseline. The primary outcome was all-cause mortality or heart failure rehospitalization within one year. RESULTS: The study participants (n = 206) were at high surgical risk (EuroSCORE II: 7.4 ± 4.8%). The primary outcome occurred in 57 patients within one year. The c-statistics for the outcome were 0.565 (95% CI 0.488-0.643) for TAPSE/ePASP and 0.695 (95% CI 0.631-0.759) for TAPSE/iPASP. The correlation between the ePASP and iPASP was attenuated in patients with massive/torrential TR compared to those with severe TR (interaction p = 0.01). In the multivariable Cox proportional model, TAPSE/iPASP was inversely associated with the risk of the primary outcome (per 0.1-point increase: adjusted-HR 0.67, 95% CI 0.56-0.82, p < 0.001), independent of baseline demographics. According to the TAPSE/iPASP quartiles (i.e., ≤ 0.316; 0.317-0.407; 0.408-0.526; ≥ 0.527), the event-free survival was 43.4%, 48.3%, 77.9%, and 85.4% at one year after TTVR. CONCLUSION: RV-PA coupling predicts one-year mortality and heart failure rehospitalization after TTVR in patients with TR. The predictability is improved if invasively-measured PA pressure is included.