Effect of Hospital Volume on Outcomes of Transcatheter Aortic Valve Implantation

Abstract

Transcatheter aortic valve implantation (TAVI) is associated with a significant learning curve. There is paucity of data regarding the effect of hospital volume on outcomes after TAVI. This is a cross-sectional study based on Healthcare Cost and Utilization Project's Nationwide Inpatient Sample database of 2012. Subjects were identified by International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes, 35.05 (Trans-femoral/Trans-aortic Replacement of Aortic Valve) and 35.06 (Trans-apical Replacement of Aortic Valve). Annual hospital TAVI volumes were calculated using unique identification numbers and then divided into quartiles. Multivariate logistic regression models were created. The primary outcome was inhospital mortality; secondary outcome was a composite of inhospital mortality and periprocedural complications. Length of stay (LOS) and cost of hospitalization were assessed. The study included 1,481 TAVIs (weighted n= 7,405). Overall inhospital mortality rate was 5.1%, postprocedural complication rate was 43.4%, median LOS was 6days, and median cost of hospitalization was $51,975. Inhospital mortality rates decreased with increasing hospital TAVI volume with a rate of 6.4% for lowest volume hospitals (first quartile), 5.9% (second quartile), 5.2% (third quartile), and 2.8% for the highest volume TAVI hospitals (fourth quartile). Complication rates were significantly higher in hospitals with the lowest volume quartile (48.5%) compared to hospitals in the second (44.2%), third (39.7%), and fourth (41.5%) quartiles (p <0.001). Increasing hospital volume was independently predictive of shorter LOS and lower hospitalization costs. In conclusion, higher annual hospital volumes aresignificantly predictive of reduced postprocedural mortality, complications, shorter LOS, and lower hospitalization costs after TAVI.