The "July Effect" in the Cardiac Catheterization Laboratory

In Interventional Cardiology, the academic year and a new training cycle begin in July. It is unclear if patient outcomes are impacted by the time of year in the training cycle. The National Cardiovascular Data Registry collects outcomes related to percutaneous coronary interventions (PCIs). We used the database for our institution to review the relation between the time of year and patient outcomes. We performed a retrospective review of National Cardiovascular Data Registry data from 2011 to 2017. Outcomes were compared between the end (quarter 2 [Q2]) and the start of the academic year (quarter 3 [Q3]). Chi-square and Fisher's exact test was used: 1,041 (Q2) and 980 (Q3) patients underwent PCI. Patient characteristics were similar between the 2 quarters except for a higher rate of heart failure for patients in Q3 (250 [24%] vs 275 [29%], p = 0.03). There was no difference in overall nonfatal adverse events between Q2 and Q3 (53 [5.1%] vs 58 [5.9%], p = 0.41). Patients in Q3 experienced a higher incidence of stroke (1 [0.1%] vs 7 [0.7%], p = 0.03) and PCI risk-adjusted mortality (8.29 [0.8%] vs 18.13 [1.9%], p = 0.03). In conclusion, there does not appear to be a significant "July Effect" in an academic cardiac catheterization laboratory in terms of most complications with an observed higher incidence of stroke and PCI risk-adjusted mortality early in the year that may be related to a difference in the characteristics of the patient population.