Impact of right ventricular-pulmonary arterial coupling on clinical outcomes of tricuspid regurgitation.

Background: In terms of pathophysiology, tricuspid regurgitation (TR) and right ventricular (RV) function are linked to each other.

Aims: This study sought to evaluate RV-pulmonary artery (PA) coupling and its impact on clinical outcomes of TR in patients undergoing mitral transcatheter edge-to-edge repair (TEER).

Methods: We calculated RV-PA coupling ratios in patients undergoing mitral TEER from August 2010 to March 2019 by dividing the tricuspid annular plane systolic excursion (TAPSE) by the echocardiographic estimated PA systolic pressure (PASP). TR was graded as none/trace, mild, moderate, or severe. The primary outcome was all-cause mortality or rehospitalisation within 12 months.

Results: Among 744 patients analysed, severe TR was documented in 22.3% of patients and the mean TAPSE/PASP was 0.43±0.25. Technical success of TEER was achieved in 97.2% of participants. Severe TR vs TR ≤moderate (adjusted HR 1.92, 95% CI: 1.39-2.66) and TAPSE/PASP (adjusted HR 0.45, 95% CI: 0.22-0.93) were associated with the outcome. Patients were divided according to the TAPSE/PASP tertile. Compared to patients with TR ≤moderate, patients with severe TR had a higher event rate (TAPSE/PASP <0.30: 32.9% vs 45.1%; 0.30≤ TAPSE/PASP <0.44: 27.8% vs 41.8%; TAPSE/PASP ≥0.44: 16.0% vs 40.4%), whereas the prognostic significance of TR was attenuated in patients with reduced TAPSE/PASP (i.e., RV-PA uncoupling; interaction term p=0.03). The trends were consistent in the multivariable regression models, spline curves, and sensitivity analysis using post-interventional parameters.

Conclusions: RV-PA coupling affects the outcome correlation of TR in patients undergoing mitral TEER. The prognostic impact of TR is attenuated in patients with RV-PA uncoupling.