Association between institutional volume of transcatheter mitral valve repair and readmission rates: A report from the Nationwide Readmission Database

Background: Transcatheter edge-to-edge repair (TEER) of the mitral valve has become an established therapy for certain patients with mitral regurgitation. However, little is known about the association between institutional volume variations and long-term outcomes using a large-scale database. Our study aimed to describe the institutional variations of TEER and also investigate its association with 180-day readmission rates. Methods: We conducted a retrospective cohort study of TEER performed in the US from the 2019 Nationwide Readmission Database. We divided the patients according to the tertiles based on volume of TEER (Q1 [lowest]-Q3 [highest]) and evaluated the association with 180-day readmission rates. Results: A total of 4922 patients (mean age 76.8 ± 10.4 years, and 54.5% male) who underwent TEER at 250 institutions were included in the analyses. There was substantial variation in the number of TEER performed annually across institutions (median 25.0 [11.6–52.5] cases). Readmission within 6-months following TEER was 37.0%, mainly due to heart failure. Higher institutional volume was associated with a reduced incidence of 180-day readmissions (HR of Q3 0.68 95%CI 0.50–0.93, vs Q1; p = 0.016). This association was more prominent in non-elective cases (HR of Q3 0.50 95%CI 0.31–0.81, vs Q1; p = 0.005). Conclusions: Using a nationally representative contemporary database, our study found substantial institutional variation in volume of TEER cases. Higher institutional volume was associated with a decreased risk of 180-day readmission rate, particularly in non-elective cases. Our study suggests the importance of highly skilled heart teams when treating patients who need urgent transcatheter intervention for mitral regurgitation.