Association Between Hospital Cardiovascular Procedural Volumes and Transcatheter Mitral Valve Repair Outcomes

Abstract

Background: Cardiovascular procedural volumes can serve as metrics of hospital infrastructure and quality, and are the basis for thresholds for initiating transcatheter mitral valve repair (TMVr) programs. Whether hospital volumes of TMVr, surgical mitral valve replacement or repair (SMVRr), and percutaneous coronary intervention (PCI) are indicators of TMVr quality of care is not known.

Methods: We used the 2017 Nationwide Readmissions Database to identify hospitals that performed at least 5 TMVr procedures. Hospitals were divided into quartiles of TMVr volume. Associations of hospital TMVr, SMVRr, and PCI volumes, as well as SMVRr and PCI outcomes with TMVr outcomes were examined. Outcomes studied were risk-standardized in-hospital mortality rate (RSMR) and 30-day readmission rate (RSRR).

Results: The study included 3404 TMVr procedures performed across 150 hospitals in the US. The median hospital TMVr volume was 17 (IQR 10, 28). The mean hospital-level RSMR and RSRR for TMVr were 3.0% (95% CI 2.5%, 3.4%) and 14.8% (95% CI 14.5%, 15.0%), respectively. There was no significant association between hospital TMVr volume (as quartiles or as a continuous variable) and TMVr RSMR or RSRR (P > 0.05). Similarly, there was weak or no correlation between hospital SMVRr and PCI volumes and outcomes with TMVr RSMR or RSRR (Pearson correlation coefficients, r = -0.199 to 0.269).

Conclusion: In this study, we found no relationship between hospital TMVr, SMVRr, and PCI volume and TMVr outcomes. Further studies are needed to determine more appropriate structure and process measures to assess the performance of established and new TMVr centers.

Keywords: MitraClip; Mortality; Readmission; Transcatheter mitral valve repair; Volume.