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.
Kinnaird T., Gallagher S., Anderson R., Sharp A., Farooq V., Ludman P., Copt S., Curzen N., Banning A., Mamas M.
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.