An international comparison of patients undergoing percutaneous coronary intervention: A collaborative study of the National Cardiovascular Data Registry (NCDR) and Japan Cardiovascular Database-Keio interhospital Cardiovascular Studies (JCD-KiCS)

Background Details on Japanese patients undergoing percutaneous coronary intervention (PCI) and how they compare to US patients remain unclear. Furthermore, the application of US risk models has not been evaluated internationally. Methods The JCD-KiCS, a multicenter registry of consecutive PCI patients, was launched in 2008, with variables defined in accordance with the US NCDR. Patient and procedural characteristics from patients enrolled from 2008 to 2010 in the JCD-KiCS database (n = 9,941) and those in the NCDR (n = 732,345) were compared. The primary outcomes of this analysis were the hospital-level all-cause mortality and bleeding complications. The NCDR risk models for these 2 outcomes were evaluated in the Japanese data set; from the expected mortality and bleeding rates, the observed/expected ratios were calculated. Results The Japanese patients were older, with a higher proportion of men, diabetes, and smoking than the US patients. The Japanese patients also had a higher rate of complex lesions (26.1 vs 12.7% for bifurcation and 6.2% vs 3.2% for chronic total occlusions, all P < .001), longerprocedure time (29.7 +/- 21.5 vs 14.4 +/- 11.5 minutes, P < .001), and higher mortality (1.6% vs 0.9%, P < .001) and bleeding rates (2.9% vs 1.8%, P < .001) compared with US patients. The observed/expected ratios for mortality and bleeding were 0.921 and 0.467, respectively, in Japanese patients, and 1.002 and 0.981, respectively, for US patients. Conclusions The characteristics of patients undergoing PCI in clinical practice in Japan and the US differ substantially. The NCDR risk models applied well in Japanese patients for prediction of mortality, but not for bleeding, which tended to underestimate the risk.