Center‐level CABG and valve operative outcomes and volume–outcome relationships in New York State

Abstract

Background: We analyzed center-level outcome correlations between valve surgery and coronary artery bypass graft (CABG) in New York (NY) State and how volume-outcome effect differ between case types. Methods: We used the 2014-2016 NY cardiac surgery outcomes report. Centerlevel observed to-expected (observed-to-expected ratio [O/E]) ratio for operative mortality provided risk-adjusted operative outcomes for isolated CABG and valve operations. Correlation coefficient characterized the concordance in center-level outcomes in CABG and valve. Discordant outcomes were defined as having O/E ratio greater than 2 in one operation type with O/E ratio ≤1 in another. Linearized slope of volume-outcome effect in case types offered insights into centers with discordant performances between procedures. Results: Among 37 NY centers, annual center volumes were 220 ± 120 cases for CABG and 190 ± 178 cases for valve operations. Modest center-level correlation between CABG and valve O/E ratio was shown (R 2 = 0.31). Two centers had discordant performance between valve and CABG (O/E ≤ 1 for CABG while O/E > 2 for valve procedures). No centers had CABG O/E ratio greater than 2 while valve O/E ratio ≤1. Linearized slope describing volume-outcome effects showed stronger effect in valve operations compared to CABG: O/E ratio declined 0.1 units per 100 CABG volume increase, while O/E ratio declined 0.33 units per 100 valve volume increase. Conclusion: In NY hospitals, favorable valve outcomes may indicate good CABG outcomes but good CABG outcomes may not ensure valve outcomes. Outcome variation in valve operation could be related to stronger volume-outcome effect in valve operations relative to CABG. Valve operations may benefit from regionalization.

Procedural Volume and Outcomes with Atrial Fibrillation Ablation: A Report from the NCDR AFib Ablation Registry

“…The association between procedure volume and outcomes has been established for other cardiovascular procedures including transcatheter aortic valve replacement 10 , implantable cardioverter defibrillator implantation 9 , percutaneous coronary intervention 8 , coronary artery bypass surgery 5 , and mitral valve surgery 6 . In this study, we observed a significant relationship between hospital and physician procedure volume and acute procedural success and safety.…”

“…Finally, underreporting is possible in this voluntary registry, although the NCDR used a rigorous data quality reporting process that includes audits of adverse events at 5% of sites annually using manual review of medical records and billing codes. The association between procedure volume and outcomes has been established for other cardiovascular procedures including transcatheter aortic valve replacement 10 , implantable cardioverter defibrillator implantation 9 , percutaneous coronary intervention 8 , coronary artery bypass surgery 5 , and mitral valve surgery 6 . In this study, we observed a significant relationship between hospital and physician procedure volume and acute procedural success and safety.…”

“…For many cardiac surgical and percutaneous procedures including coronary artery bypass grafting 5 , mitral valve surgery 6 , percutaneous coronary artery intervention 7,8 , implantable cardioverter defibrillator implantation 9 , and transcatheter aortic valve replacement 10 , higher procedural volumes have been associated with improved outcomes. Despite these known associations between procedural volume and outcomes in other cardiac procedures, the relationship between physician and hospital procedure volumes and outcomes for AF catheter ablation in contemporary practice is not well studied.…”