Impact of operator volume for percutaneous coronary intervention on clinical outcomes: what do the numbers say?

The impact of operator and centre volume on clinical outcomes and quality of care has been of considerable debate in recent years in a number of surgical- and procedural-based specialities. A relationship between higher volumes at both the institutional and operator levels and better clinical outcomes would at first appear intuitive, based on the premise that performing a procedure very infrequently would be likely to lead to unfamiliarity, complications, and poorer outcomes. In the current review, we study the relationship between operator volume and outcomes in the setting of percutaneous coronary intervention (PCI), and examine the evidence for current clinical competency guidelines that advocate that a minimum number of PCI procedures be undertaken annually. Whilst both high institutional and operator volumes have been shown to be associated with better outcomes by reducing death and in-hospital mortality, these data are often derived from the pre-stent era, or when high-volume operators undertook far smaller numbers of procedures than is currently recommended to maintain clinical competency. The emphasis of specific volume requirements for optimal outcomes needs to be interpreted with caution, as volume is not a surrogate for quality and merely one of the variables associated with outcome. Healthcare providers should focus on other measures of quality such as robust clinical care pathways, evidence-based treatments, periodic case review, using validated risk assessment scores, and ascertainment of outcome to improve care and reduce adverse events.