AIMS: This study sought to evaluate the impact of asymmetric mitral valve (MV) leaflet tethering on procedural and mortality outcome in patients undergoing transcatheter edge-to-edge mitral valve repair (TMVR) for secondary mitral regurgitation (SMR).

METHODS AND RESULTS: We included 302 consecutive patients who underwent TMVR for severe MR between 2009 and 2019 at a high-volume quaternary care center. Anterior and posterior MV leaflet angles were defined as the angles between MV plane and the tangent on the root of the respective leaflet. Asymmetric MV tethering was defined as ratio of the anterior to the posterior MV leaflet angle >1.57, derived from receiver operating characteristics analysis. In 89 patients (30%), the tethering pattern was asymmetric. This condition was associated with higher rates of postprocedural MR severity >2+, despite implantation of a higher number of clips. Multivariable Cox regression revealed left ventricular ejection fraction (per 10% decrease, hazard ratio [HR]=1.38, confidence interval [CI]=1.04-1.83, p=0.03), estimated glomerular filtration rate (eGFR, per 10 ml/min decrease HR=1.22, CI= 1.09-1.38, p<0.01), and asymmetric MV leaflet tethering (HR=2.04, CI=1.26-3.31, p<0.01) as predictors two-year all-cause mortality after TMVR for severe SMR.

Conclusions: TMVR safely and effectively reduces SMR. Asymmetric mitral valve tethering is present in about 30% of SMR patients and is an important anatomic factor associated with less MR reduction despite higher numbers of implanted clips as well as increased mortality. In patients with asymmetric leaflet tethering alternative percutaneous treatment solutions, among others transcatheter mitral valve implantation, should be investigated to improve long-term outcomes.