Direct oral anticoagulants (DOACs) have increasingly replaced warfarin for treating patients with non-valvular atrial fibrillation (NVAF). DOACs have been demonstrated to be more useful than warfarin, which was highlighted at its ethnic differences in efficacy and safety; however, the regional differences of DOACs remain unclear. We conducted a systematic review, meta-analysis, and meta-regression to evaluate the efficacy and safety of DOACs in patients from Asian and non-Asian regions with NVAF. We systematically searched randomized control trials published before August 2019. We defined 11 studies comprising 7,118 Asian and 53,282 non-Asian patients, totaling 60,400 patients with NVAF. The risk ratios (RRs) of DOACs were calculated against warfarin. The efficacy of DOACs was significantly higher in Asian regions regarding stroke/systemic embolism events (RR: 0.62 and 95% confidence interval (CI): 0.49-0.78 for the Asian region; RR: 0.83 and 95% CI: 0.75-0.92 for non-Asian regions; P interaction: 0.02), when compared with warfarin. The safety of DOACs was significantly higher in Asian regions regarding major bleeding (RR: 0.62 and 95% CI: 0.51-0.75 for Asian regions; RR: 0.90 and 95% CI: 0.76-1.05 for non-Asian regions; P interaction: 0.004), compared with warfarin. In addition, we conducted meta-regression analysis to discuss the true regional differences of DOACs to warfarin. The meta-regression analysis, which adjusts the effect of individual backgrounds in each study, indicated that the regional differences were observed in the efficacy but not in drug safety. These results suggest that treatment with DOACs may be more effective than the conventional warfarin in the Asian region.

Percutaneous coronary intervention (PCI) sometimes causes ischemic heart disease (IHD). Statins have a recovery effect on vascular endothelial cell function, and it is suggested that statin administration during PCI may help prevent IHD. However, this has not been validated by a large-scale clinical study. Therefore, we evaluated the relationship between statin administration during PCI and cardiovascular events by analyzing the national claims database, which covers most residents in Japan. We analyzed patients who underwent PCI, who were diagnosed with angina or myocardial infarction, and had been continuously administered statin. Among these patients, we assigned patients who were administered statins for 7 days before the procedure to the exposure group and those who were not to the non-exposure group. After matching patients backgrounds using two statistical methods, we compared the incidence of IHD, atrial brillation, bleeding, and mortality after the procedure. The results indicated lower incident risks of IHD and atrial fibrillation after the procedure in angina patients in the exposure group and lower mortality after the procedure in myocardial infarction patients in the exposure group. These results suggest that perioperative treatment with statin during PCI could improve PCI prognosis.