Prognosis of Tricuspid Regurgitation after Mitral Transcatheter Edge-to-Edge Repair: The EXPANDed Studies

BACKGROUND: Transcatheter therapies offer new treatment options for patients with both mitral regurgitation (MR) and tricuspid regurgitation (TR). However, the optimal treatment pathway in patients with combined MR and TR is not completely understood. AIMS: This analysis evaluated the natural TR progression after mitral transcatheter edge-to-edge repair (MTEER) with the MitraClip System in patients with MR and TR from the EXPANDed studies. METHODS: EXPANDed is a pooled cohort from the EXPAND and EXPAND G4 studies. This study includes patients who had severe TR, achieved procedural success with MTEER, and received no direct TR intervention. Echocardiographic assessments were performed independently by echo core lab. Baseline characteristics, 1-year outcomes, and associations with TR improvement were reported based on 30-day TR severity following MTEER. RESULTS: Of those with evaluable TR data at 30 days (N=160), 73% (N=116) improved to ≤moderate TR, while 28% (N=44) had ≥severe TR. The ≤moderate TR group had a lower prevalence of atrial fibrillation (68% vs 89%, p=0.009), numerically lower LV ejection fraction (49% vs 56%, p=0.07), and larger LV dimensions (LVEDV: 137.5±73.4 vs 107.9±44.8 ml, p=0.01). TR reduction was sustained in 86% of ≤moderate TR patients, while 45% of ≥severe TR patients improved to ≤moderate at 1 year. In the ≤moderate TR group, significant and larger improvements in NYHA functional class (p<0.0001) and KCCQ-OS score (Δ = +30.6±25.7, p<0.0001) were observed through 1 year. One-year mortality was numerically lower in the ≤moderate TR group (12.4% vs 22.3%) though not statistically significant (HR=1.92 [0.77, 4.79], p=0.16). Lower LVEF and larger baseline LV size were associated with TR improvement post-MTEER. CONCLUSIONS: Early TR improvement to ≤moderate was observed in almost 3/4 of the population and was associated with significant symptomatic relief. Patients with both severe MR and TR, particularly those with LV dilation, may experience TR improvement following MTEER.