Utilization of Anticoagulant and Antiplatelet Agents Among Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention　- Retrospective Cohort Study Using a Nationwide Claims Database in Japan.

Background: The European Society of Cardiology recommends a risk-based antithrombotic strategy for patients with atrial fibrillation (AF) who undergo percutaneous coronary intervention (PCI) based on CHA ₂ DS ₂ -VASc and HAS-BLED scores. However, because it is unclear if that strategy can be generalized to Asians, we aimed to describe antithrombotic therapies among Japanese patients.
Methods and results: Using a nationwide claims database in Japan, this retrospective cohort study identified AF patients who underwent PCI from April 1, 2014 to March 31, 2015. The primary outcome was utilization of anticoagulant and antiplatelet agents before PCI, at discharge, and 6, 9, and 12 months after PCI. The secondary outcome was incidence of stroke after PCI. We identified 10,862 patients and 87.5% of them had high CHA ₂ DS ₂ -VASc and HAS-BLED scores. There were no significant differences in antithrombotic therapies across the risk strata. More than 30% of patients at high risk of thrombosis did not receive oral anticoagulant prescriptions at discharge. The hazard ratio of incidence of stroke in patients with prior stroke compared with patients without prior stroke was 9.09 (95% confidence interval 7.86-10.50, P<0.01).
Conclusions: Among Japanese AF patients who underwent PCI, prescriptions for antiplatelet agents were more common than those for anticoagulant agents. The majority of study participants were classified as high risk, suggesting a need for a new risk classification that reflects the risk profiles of Japanese patients.