Impact of percutaneous mitral valve repair using the MitraClip system on tricuspid regurgitation

AIMS: Tricuspid regurgitation (TR) severity and right ventricular (RV) dysfunction have been identified as significant predictors of outcome after mitral valve surgery. The aim of the present study was to investigate the impact of percutaneous mitral valve repair (PMVR) with the MitraClip system on functional TR severity and RV function. METHODS AND RESULTS: Among 119 consecutive patients with severe mitral regurgitation who underwent PMVR, 67 had complete baseline and follow-up transthoracic echocardiography after 3-12 months (6.8±2.9 months). TR severity was graded as mild, moderate, and severe. RV systolic function was assessed by fractional area change (FAC) and tricuspid annular plane systolic excursion (TAPSE). Clinical endpoints at follow-up included mortality, reoperation of the mitral valve, hospitalisation for congestive heart failure and New York Heart Association (NYHA) functional class. After PMVR, a significant decrease in TR severity (by at least one grade) was observed in 22 (33%) patients, while an increase occurred in only seven (10%) patients (p=0.02). Overall, systolic RV function (FAC and TAPSE), RV dimensions, and tricuspid annular diameter did not change significantly. Baseline SPAP was significantly higher (57±15 vs. 43±14 mmHg, p=0.002) and SPAP reduction significantly larger (-14±13 versus 1±15 mmHg, p=0.012) in patients who improved their TR. Multivariate logistic regression analysis identified the change in SPAP as the only significant predictor of changes in TR (odds ratio OR for every change in SPAP by 10 mmHg 1.90, 95% CI: 1.02±3.54; p=0.044). Patients with mild/moderate TR at follow-up after PMVR had lower event rates compared to those with severe TR (35% vs. 78%, respectively, p=0.025). CONCLUSIONS: PMVR using the MitraClip device improves functional TR severity in approximately one third of patients, particularly in those who experience a significant SPAP reduction after the procedure.