National Variation in Hospital MTEER vs. TAVR Outcomes

Quick Takes

  • Using data from the STS/ACC TVT registry, there was modest correlation between hospital-level annualized volumes for TAVR and mitral transcatheter edge-to-edge repair (MTEER) procedures.
  • However, there was low correlation of clinical outcomes between the two procedures.

Study Questions:

Is there a relationship between site-level volumes and outcomes for transcatheter aortic valve replacement (TAVR) and mitral transcatheter edge-to-edge repair (MTEER)?


The STS/ACC TVT (Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy) national registry was used to identify TAVR and MTEER procedures at sites offering both therapies from 2013 to 2022, excluding procedures performed at hospitals performing <20 TAVR or MTEER procedures over the study period. Annualized hospital volume was calculated as 12 x (total number of each procedure / total months between the first and last procedure). Sites were ranked into deciles of adjusted in-hospital and 30-day outcomes separately for TAVR and MTEER and compared. Stepwise, hierarchical multivariable models were constructed for MTEER outcomes, and the median odds ratio was calculated.


Between 2013 and 2022, 384,394 TAVRs and 53,274 MTEERs (median annualized volumes 93.6 and 18.8, respectively) were performed across 453 US sites. Annualized TAVR and MTEER volumes were moderately correlated (r = 0.48, p < 0.001). After adjustment, 14.3% of sites had the same decile rank for TAVR and MTEER 30-day composite outcome, 50.6% were within 2 decile ranks, and 35% had more discordant outcomes for the two procedures (p = 0.0005). For MTEER procedures, the median odds ratio for the 30-day composite outcome was 1.57 (95% confidence interval, 1.51-1.64), indicating a 57% variability in outcome by site.


There is modest correlation between hospital-level volumes for TAVR and MTEER but low interprocedural correlation of outcomes. For similar patients, site-level variability for mortality/morbidity following MTEER was high. The authors conclude that factors influencing outcomes and “centers of excellence” as a whole may differ for TAVR and MTEER.


Based on a general correlation between hospital volume and procedural outcomes, current multi-society guidelines endorse minimum volume thresholds for TAVR and MTEER and referral of patients with complex valve disease to a heart valve center of excellence. Implicit in this concept is that the heart valve center of excellence performs equally well for all valve procedures. This study documented moderate correlation between hospital-level TAVR and MTEER procedural volumes, but discordance between outcomes for the two procedures; such that centers with better outcomes for TAVR might have higher procedural volumes for MTEER but might not have equivalently good outcomes for MTEER.

Study limitations include the inclusion of only sites that performed both procedures (excluding almost half of US sites that perform only one or the other) and potential underestimation of procedural volumes at sites that enroll patients in clinical trials (which are not included in the STS/ACC TVT registry). However, as the authors note, potential policy ramifications of the study are that centers of excellence might differ for aortic valve and mitral valve procedures.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Cardiac Surgery and VHD, Interventions and Structural Heart Disease, Mitral Regurgitation

Keywords: Mitral Valve Insufficiency, STS/ACC TVT Registry, Transcatheter Aortic Valve Replacement

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