Aims: We aimed to assess whether transcatheter mitral valve repair (TMVR) influences early right ventricular function (RVF), and to determine whether these potential changes are associated with clinical outcomes.

Methods and Results:We analysed data for 816 patients enrolled in the prospective Heart Failure Network Rhineland registry, all of whom had undergone TMVR using the MitraClip system for the treatment of severe MR between August 2010 and March 2019. We examined RVF before and after TMVR. RV dysfunction was defined as a change in RV fractional area <35% or tricuspid annular plane systolic excursion <16 mm. The primary endpoint was a composite of all-cause mortality and unexpected rehospitalisation due to heart failure (HF). At a median time of 3 days (interquartile range [IQR]: 2-5 days) after the procedure, RVF remained normal in 34% (n=274), improved in 17% (n=140), and declined in 15% (n=125) of patients. However, 34% (n=277) of patients exhibited persistent RV dysfunction. Event rates significantly differed based on changes in RVF (log-rank test, p<0.001). After adjustment, postprocedural RV dysfunction was associated with an increased risk of the primary endpoint (hazard ratio (HR): 1.64, 95% confidence interval (95%CI): 1.18-2.29, p=0.003). In patients with normal RVF at baseline, RVF decline was associated with an increased risk of the primary endpoint (HR: 1.88, 95%CI: 1.07-3.30, p=0.03).

Conclusion: Early changes in RVF are common following TMVR. Our findings indicate that RVF deterioration and persistent RV dysfunction are associated with an increased risk of all-cause mortality and unexpected HF hospitalization during follow-up.