Coronary artery bypass grafting in Spain. Influence of procedural volume on outcomes

Abstract Introduction and objectives To analyze the association between volume and outcomes in coronary artery bypass grafting (CABG) in the Spanish National Health System. Methods We analyzed CABG episodes from 2013 to 2015. The selected outcome variables were in-hospital mortality in the index episode, 30-day cardiac-related readmissions, and mortality during readmission. Risk-adjusted rates of in-hospital mortality (RAMR) and 30-day readmissions (RARR) were calculated using multilevel logistic regression. High- and low-volume hospitals for CABG were identified by a nonconditioned analysis (k-means) and by compliance with the volume recommendation of clinical practice guidelines. Results A total of 17 335 CABG index episodes were included, with a crude in-hospital mortality rate of 5.0%. Episodes attended in low-volume centers for CABG ( Conclusions The mean CABG volume is low in Spanish National Health System hospitals. Higher volume was associated with better outcomes in CABG, both total and isolated. The findings of this study indicate the need for a higher concentration of CABG programs, as well as the publication of risk-adjusted outcomes of coronary intervention.