Variation in in-hospital mortality and its association with procedure-related bleeding complications: a report from nationwide percutaneous coronary intervention registry in japan

Abstract

Abstract Background Large-scale registries have demonstrated that in-hospital mortality after percutaneous coronary intervention (PCI) varies widely across institutions; however, the underlying reasons are not fully understood. Bleeding has been regarded as one of the most serious PCI-related complications associated with increase in mortality. To date, reducing bleeding complications have tended to be addressed, though appropriate care for patients who developed bleeding complications may be also important. Therefore, we sought to investigate which was more involved in the inter-institutional variations in in-hospital mortality. Methods We analyzed 388,866 procedures at 718 hospitals performed from 2017 to 2018, using data from a representative nationwide PCI registry in Japan. A bleeding complication was defined as post-procedural bleeding that required a blood transfusion. We first divided the hospitals into quintiles according to their risk-adjusted in-hospital mortality (very low, low, medium, high, and very high). Then, the bleeding complication rate and in-hospital mortality rate among patients who developed bleeding complications were calculated for each quintile. Results In total, 4,048 (1.04%) in-hospital deaths and 1,535 (0.39%) bleeding complications occurred. In-hospital mortality varied widely from 0.22% to 2.46% in very-low- to very-high-mortality hospitals. The bleeding complication rate also increased modestly from 0.27% to 0.57% (odds ratio, 1.95; 95% confidence interval, 1.58–2.39). However, the mortality rate among patients who developed bleeding complications markedly increased by quintile; the mortality rate of very-high-morality hospitals was 6-fold higher than that of very-low-mortality hospitals (29.0% vs. 4.8%, respectively; odds ratio, 12.2; 95% confidence interval, 6.9–21.7). Conclusions Wide variation in in-hospital mortality was observed within the Japanese nationwide PCI registry, and this variation was largely driven by differences in mortality among patients with bleeding complications, rather than crude incidence of bleeding complications. These results underscore the importance of efforts toward reducing not only bleeding complications but also, even more importantly, mortality once bleeding has occurred. Funding Acknowledgement Type of funding sources: None.