Are Higher Operator Volumes for Unprotected Left Main Stem Percutaneous Coronary Intervention Associated With Improved Patient Outcomes?: A Survival Analysis of 6724 Procedures From the British Cardiovascular Intervention Society National Database.

Abstract

BACKGROUND: The relationship between operator volume and survival after unprotected left main stem percutaneous coronary intervention (uLMS-PCI) is poorly defined. METHODS: Data from the British Cardiovascular Intervention Society national PCI database were analyzed for all uLMS-PCI procedures performed in England and Wales between 2012 and 2014 and 4 quartiles of annualized uLMS-PCI volume (Q1-Q4) generated. Individual logistic regressions were performed for 12-month mortality to quantify the independent association between operator quartile and outcomes. RESULTS: In total, 6724 uLMS-PCI procedures were analyzed with a negatively skewed distribution and an annualized median of 3 procedures per year. Operator volume ranged from 1 to 54 uLMS-PCI procedures/year. Within Q1, 347 operators performed a median of 2 procedures/year (interquartile range, 1-3); in Q2, 134 operators performed a median of 5 procedures/year (interquartile range, 4-6); in Q3, 59 operators performed a mean of 10 procedures/year (interquartile range, 8-12); and in Q4, 29 operators performed a mean of 21 procedures/year (interquartile range, 17-29). Higher volume operators undertook uLMS-PCI in patients with greater comorbid burden and performed more complex procedures compared with lower operator volumes. Adjusted in-hospital survival (odds ratio, 0.39 [95% CI, 0.24-0.67]; P<0.001), in-hospital major adverse cardiac and cerebral events (odds ratio, 0.41 [95% CI, 0.27-0.62]; P<0.001), and 12-month survival (odds ratio, 0.54 [95% CI, 0.39-0.73]; P<0.001) were lower in Q4 operators compared with Q1 operators. A close association between operator volume/case and superior 12-month survival was observed (P<0.001). The lower volume threshold of minimum operator uLMS-PCI volume associated with improved survival was =16 cases/year. CONCLUSIONS: These data suggest that operator volume is an important factor in determining outcome after uLMS-PCI.