Institutional Experience With Transcatheter Mitral Valve Repair And Clinical Outcomes: Insights From the TVT Registry

Objectives: The aim of this study was to examine the relation between institutional experience and procedural results of transcatheter mitral valve repair.

Background: Transcatheter mitral valve repair for the treatment of mitral regurgitation (MR) is a complex procedure requiring navigation of the left atrium, left ventricle, and mitral valve apparatus using echocardiographic guidance.

Methods: MitraClip procedures from the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry were stratified into tertiles on the basis of site-specific case sequence (1 to 18, 19 to 51, and 52 to 482). In-hospital outcomes of procedural success, procedural time, and procedural complications were examined. To evaluate the learning curve for the procedure, generalized linear mixed models were developed using case sequence number as a continuous variable.

Results: MitraClip procedures (n = 12,334) performed at 275 sites between November 2013 and September 2017 were analyzed. Optimal procedural success (≤1+ residual MR without mortality or need for cardiac surgery) increased across tertiles of case experience (62.0%, 65.5%, and 72.5%; p < 0.001), whereas procedural time and procedural complications decreased. Acceptable procedural success (≤2+ residual MR without death or need for cardiac surgery) also increased across tertiles of case experience, but the differences were smaller (91.2%, 91.2%; and 92.9%; p = 0.006). In the learning-curve analysis, visual inflection points for procedural time, procedural success, and procedural complications were evident after about 50 cases, with continued improvements observed up to 200 cases.

Conclusions: For transcatheter mitral valve repair with the MitraClip, increasing institutional experience was associated with improvements in procedural success, procedure time, and procedural complications. The impact of institutional experience was larger when considering the goal of achieving optimal MR reduction.