Difference in Patient Profiles and Outcomes in Japanese Versus American Patients Undergoing Coronary Revascularization (Collaborative Study by CREDO-Kyoto and the Texas Heart Institute Research Database)

Although coronary revascularization is common in both Japan and the United States (US), no direct comparison has been performed to demonstrate differences in the clinical characteristics and long-term outcomes of patients in these 2 countries. We analyzed the preprocedural, in-hospital, and long-term data from the Coronary Revascularization Demonstrating Outcome registry (Kyoto, Japan) and the Texas Heart Institute Research Database (Houston, Texas) of 16,100 patients who had undergone elective, initial percutaneous coronary intervention or coronary artery bypass grafting. The Japanese procedures were performed from 2000 to 2002 (n = 8,871, follow-up period 3.5 years, interquartile range 2.6 to 4.3) and the US procedures from 1999 to 2003 (n = 7,229, follow-up period 5.2 years, interquartile range 3.8 to 6.5). The Japanese patients tended to be older (mean age 67.2 vs 62.7 years; p <0.001), to smoke (52.9% vs 46.0%; p <0.001), and to have diabetes (39.2% vs 31.0%; p <0.001) and stroke (16.4% vs 5.0%; p <0.001). The US patients were more obese (body mass index 23.7 vs 29.3 kg/m²; p <0.001), with greater rates of systemic atherosclerotic disease. Both groups had a similar in-hospital mortality rate (Japanese patients 0.9% vs US patients 1.1%; p = 0.19) and crude long-term mortality rate (Japanese patients 27.7/1,000 person-years, US patients 28.2/1,000 person-years; p = 0.35). After adjustment for known predictors, the US group had greater long-term mortality than the Japanese group (hazard ratio 1.71, 95% confidence interval 1.50 to 1.95; p <0.001). This finding was consistent among all high-risk subgroups. In conclusion, the 2 registries showed similar crude outcomes but important differences in patient risk factors such as obesity. In the adjusted analysis, the Japanese patients had better outcomes than did the US patients. Additional study is needed to assess the effect of ethnic and risk factor variations on coronary artery disease.