Outcomes of transcatheter edge-to-edge repair for atrial functional mitral regurgitation.

BACKGROUND: The prognostic benefits of transcatheter edge-to-edge repair (TEER) remain unclear in patients with atrial functional mitral regurgitation (AFMR). AIMS: We aimed to investigate the clinical outcomes of TEER for patients with AFMR. METHODS: We retrospectively classified functional mitral regurgitation (FMR) patients undergoing TEER into those with AFMR or ventricular FMR (VFMR). A residual MR ≤1+ at discharge was considered optimal mitral regurgitation (MR) reduction, and an elevated mean mitral valve pressure gradient (MPG) was defined as an MPG ≥5 mmHg at discharge. The primary outcome was a composite of all-cause mortality and hospitalisation due to heart failure within one year. RESULTS: Of 441 FMR patients, 125 patients were considered as having AFMR. Residual MR ≤1+ was associated with a lower risk of the composite outcome in both AFMR and VFMR patients, while an MPG ≥5 mmHg was associated with a higher risk of the composite outcome in patients with AFMR but not with VFMR. AFMR patients with residual MR ≤1+ and an MPG ≥5 mmHg, as well as those with residual MR >1+, had a higher incidence of the composite outcome than those with residual MR ≤1+ and an MPG <5 mmHg (50.7%, 41.8%, and 14.3%, respectively; p<0.001). This association was consistent after adjustment for clinical and echocardiographic characteristics. CONCLUSIONS: An MR reduction to ≤1+ following TEER was associated with a lower risk of clinical outcomes in patients with AFMR, while an MPG ≥5 mmHg was related to a higher risk of clinical outcomes. Optimal MR reduction by TEER may have potential benefits on the prognosis of patients with AFMR, although the prognostic benefit may be attenuated by an elevated MPG.

Predictors of functional improvement in the short term after MitraClip implantation in patients with secondary mitral regurgitation.

BACKGROUND AND OBJECTIVES: MitraClip implantation is an established therapy for secondary mitral regurgitation (MR) in high-risk patients and has shown to improve several important outcome parameters such as functional capacity. Patient selection is both challenging and crucial for achieving therapeutic success. This study investigated baseline predictors of functional improvement as it was quantified by the six-minute walk distance (6MWD) after transcatheter mitral valve repair. METHODS AND RESULTS: We retrospectively analyzed 79 patients with secondary MR treated with MitraClip implantation at an academic tertiary care center. Before and four weeks after the procedure, all patients underwent comprehensive clinical assessment, six-minute walk tests and echocardiography. 6MWD significantly improved after MitraClip therapy (295 m vs. 265 m, p < 0.001). A linear regression model including seven clinical baseline variables significantly predicted the change in 6MWD (p = 0.002, R2 = 0.387). Female gender, diabetes mellitus and arterial hypertension were found to be significant negative predictors of 6MWD improvement. At baseline, female patients had significant higher left ventricular ejection fraction (49% vs. 42%, p = 0.019) and lower 6MWD (240 m vs. 288 m, p = 0.034) than male patients. CONCLUSION: MitraClip implantation in secondary MR significantly improves functional capacity in high-risk patients even in the short term of four weeks after the procedure. Female gender, diabetes mellitus and arterial hypertension are baseline predictors of a less favourable functional outcome. While further validation in a larger cohort is recommended, these parameters may improve patient selection for MitraClip therapy.