Combined MitraClip and TriClip therapy in patients with severe mitral and tricuspid regurgitation: determinants and prediction of mid-term outcomes.

BACKGROUND

Patients with combined severe mitral (MR) and tricuspid regurgitation (TR) constitute a high-risk cohort with advanced right-heart disease, reduced survival, and frequent heart failure hospitalizations. While transcatheter edge-to-edge repair (TEER) is guideline-endorsed for severe MR and increasingly adopted for TR, long-term evidence on combined dual-valve TEER remains limited. The TRIVALVE score has shown prognostic utility in transcatheter tricuspid interventions but has not been specifically evaluated in patients requiring combined TEER.

METHODS

We prospectively enrolled 54 consecutive patients with severe MR and TR undergoing combined TEER by means of MitraClip® and TriClip®. Baseline clinical, echocardiographic, and laboratory data were collected. The primary endpoint was all-cause mortality; the secondary endpoint was a composite endpoint of all-cause mortality or heart failure rehospitalization (cumulative events). Survival and cumulative events were estimated by Kaplan-Meier analysis, determinants were identified by logistic regression, and prediction models were built using random-forest, logistic regression, and gradient boosting.

RESULTS

Median TRIVALVE score was 2.0 (IQR 1.0-3.0) and median EuroSCORE II was 4.5 (IQR: 3.0-7.6). Thirty-day mortality was 5.5% (3/54). Median clinical follow-up was 607 days (IQR 289-906). Estimated 1-year and 2-year survival was 91.8% and 64.5%, with 74.2% and 52.7% freedom from mortality or heart failure rehospitalization. In the regression analysis, both TRIVALVE score (OR=2.19; 95% CI: 1.06-4.53; p = 0.034) and baseline level of hemoglobin (OR=0.64; 95% CI: 0.43-0.96; p = 0.029) were significantly associated with mortality. The composite of all-cause mortality or heart-failure rehospitalization was independently predicted by the TRIVALVE score (OR=2.53; 95% CI: 1.26-5.09; p = 0.009) with the component of pre-procedural atrial fibrillation and right heart failure having the strongest prediction. Random forest showed the highest discriminative performance for prediction of follow-up mortality (AUC 0.79; Sens. 0.84; Spec. 0.66; 95% CI 0.63-0.96), and the composite of all-cause mortality or heart-failure rehospitalization (AUC 0.86; Sens.0.8; Spec. 0.67; 95% CI 0.718-0.976).

CONCLUSION

Combined dual-valve TEER achieved acceptable mid-term survival and event-free outcomes. Outcomes were driven more by baseline disease burden than by procedural success alone. Lower baseline hemoglobin and a higher TRIVALVE score were both linked to worse prognosis, with atrial fibrillation and right heart failure as its most influential components, highlighting the contribution of chronic atrial remodeling and congestion to recurrent events. These findings are hypothesis-generating and require external validation.