Operator Experience and Procedural Results of Transcatheter Mitral Valve Repair in the United States.

BACKGROUND: Transcatheter mitral valve repair (TMVr) for the treatment of mitral regurgitation (MR) is a complex procedure that requires development of a unique skillset.

OBJECTIVE: To examine the relationship between operator experience and procedural results of TMVr with MitraClip (Abbott Structural, Santa Clara, CA).

METHODS: TMVr device procedures from the STS/ACC TVT Registry were analyzed with operator case number as a continuous and categorical (1-25, 26-50, and >50) variable. Outcomes of procedural success, procedural time, and in-hospital procedural complications were examined. The learning curve for the procedure was evaluated using generalized linear mixed models adjusting for baseline clinical variables.

RESULTS: All TMVr device procedures (n=14,923) performed by 562 operators at 290 sites between November 2013 and March 2018 were analyzed. Optimal procedural success (≤ 1+ residual MR without death or cardiac surgery) increased across categories of operator experience (63.9%, 68.4%, and 75.1%; p<0.001), while procedural time and procedural complications decreased. Acceptable procedural success (≤ 2+ residual MR without death or cardiac surgery) also increased with operator experience, but the differences were smaller (91.4%, 92.4%, and 93.8%, p<0.001). These associations remained significant in adjusted, continuous variable analyses. Visual inflection points in the learning curves for procedural time, procedural success, and procedural complications were evident after approximately 50 cases, with continued improvements observed up to 200 cases.

CONCLUSIONS: For TMVr device proceedures, operator experience was associated with improvements in procedural success, procedure time, and procedural complications. The impact of operator experience was greater when considering the goal of achieving 1+ residual MR.