Association Between Operator Procedure Volume and Patient Outcomes in Percutaneous Coronary Intervention A Systematic Review and Meta-Analysis

Background-The growth of centers capable of performing percutaneous coronary intervention (PCI) has outpaced population growth despite declining incidence of myocardial infarction and prevalence of coronary artery disease, potentially increasing the proportion of operators falling below minimal yearly volume standards set by professional societies. Methods and Results-Electronic literature search of MEDLINE and the Cochrane Library for English-language articles published between 1977 and November 2012 was performed. Title and abstract review followed by full-text and references review were performed by 2 authors independently to identify studies examining the association between operator volume and outcomes in PCI. Using a standardized form, 2 authors abstracted information on study design, methods, outcomes, statistical methods, and conclusions. Studies were categorized according to methodological quality and outcomes. Meta-analyses were performed by outcome using a random-effects model. Of the 23 studies included in the analysis, 14 (61%) evaluated mortality, 7 (30%) evaluated major adverse cardiac events, and 2 (9%) evaluated angiographic success. In total, the studies evaluated 15 907 operators performing 205 214 PCIs on 1 109 103 patients at 2456 centers with a mean follow-up of 2.8 years. Eleven (48%) were considered higher quality. Studies with higher methodological quality and large sample sizes more often showed a relationship between operator volume and outcomes in PCI. Higher volume was associated with improved major adverse cardiac events at every threshold, regardless of the threshold evaluated. Conclusions-Mortality and major adverse cardiac events increase as operator volumes decrease in PCI. Among studies showing a relationship, high-volume operators were defined variably, with annual PCIs ranging from >11 to >270, with no clear evidence of a threshold effect within the ranges studied.