Refining accuracy of RV-PA coupling in patients undergoing transcatheter tricuspid valve treatment

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).

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.

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.

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.