Ken Okumura1,2, Hirofumi Tomita1, Michikazu Nakai3, Eitaro Kodani4, Masaharu Akao5, Shinya Suzuki6, Kenshi Hayashi7, Mitsuaki Sawano8, Masahiko Goya9, Takeshi Yamashita6, Keiichi Fukuda8, Hisashi Ogawa5, Toyonobu Tsuda7, Mitsuaki Isobe9,10, Kazunori Toyoda11, Yoshihiro Miyamoto12, Hiroaki Miyata13, Tomonori Okamura14, Yusuke Sasahara3. 1. Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan. 2. Division of Cardiology, Saiseikai Kumamoto Hospital, Kumamoto, Japan. 3. Center for Cerebral and Cardiovascular Disease Information, National Cerebral and Cardiovascular Center, Suita, Japan. 4. Department of Internal Medicine and Cardiology, Nippon Medical School Tama-Nagayama Hospital, Tokyo, Japan. 5. Department of Cardiology, National Hospital Organization Kyoto Medical Center, Kyoto, Japan. 6. Department of Cardiovascular Medicine, The Cardiovascular Institute, Tokyo, Japan. 7. Department of Cardiovascular Medicine, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan. 8. Department of Cardiology, Keio University School of Medicine, Tokyo, Japan. 9. Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan. 10. Sakakibara Heart Institute, Tokyo, Japan. 11. Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan. 12. Department of Preventive Cardiology, National Cerebral and Cardiovascular Center, Suita, Japan. 13. Department of Health Policy and Management School of Medicine, Keio University, Tokyo, Japan. 14. Department of Preventive Medicine and Public Health, Keio University School of Medicine, Tokyo, Japan.
Abstract
Importance: Despite the development of risk stratification schemes that have been widely used to determine the risk for thromboembolism in patients with nonvalvular atrial fibrillation (NVAF), risk stratification schemes in Asian patients with NVAF remain undetermined. Objective: To determine risk factors for ischemic stroke in Japanese patients with NVAF. Design, Setting, and Participants: This cohort study analyzed individual patient data from 5 AF registries in Japan: J-RHYTHM (Japanese Rhythm Management Trial for Atrial Fibrillation) Registry, Fushimi AF Registry, Shinken Database, Keio Interhospital Cardiovascular Studies (Keio Study), and Hokuriku-Plus AF Registry. Patients with atrial fibrillation were registered from 158 institutions in the J-RHYTHM Registry, 80 in the Fushimi AF Registry, a single hospital in Shinken Database, 11 in the Keio Study, and 19 in the Hokuriku-Plus AF Registry. Patients with valvular AF or lacking data were excluded. Data were collected and integrated in March 2016, and those from the Keio Study were updated in April 2018. Data were analyzed from April 2018 to February 2020. Main Outcomes and Measures: Significant risk factors for ischemic stroke were determined by adjusted Cox proportional hazards analysis. Results: In total, 12 289 patients with NVAF (3758 [31%] female; mean [SD] age 70.2 [11] years) were analyzed with a mean (SD) follow-up period of 649 (181) days (1.8 [0.5] years). During 21 820 person-years of follow-up, 241 cases of ischemic stroke were reported. Risk factors associated with ischemic stroke after adjustment for oral anticoagulant use at enrollment were age (75-84 years: hazard ratio [HR], 1.74; 95% CI, 1.32-2.30; P < .001; and ≥85 years: HR, 2.41; 1.63-3.56; P < .001), hypertension (HR, 1.60; 95% CI, 1.15-2.23; P = .006), previous stroke (HR, 2.75; 95% CI, 2.09-3.62; P < .001), persistent or permanent AF (HR, 1.59; 95% CI, 1.21-2.10; P = .001), and body mass index less than 18.5 (HR, 1.55; 95% CI, 1.05-2.29; P = .03). Neither diabetes nor heart failure were identified as risk factors for ischemic stroke. Conclusions and Relevance: Previous stroke, advanced age, hypertension, persistent or permanent AF, and low body mass index were independent risk factors associated with ischemic stroke in Japanese patients with NVAF.
Importance: Despite the development of risk stratification schemes that have been widely used to determine the risk for thromboembolism in patients with nonvalvular atrial fibrillation (NVAF), risk stratification schemes in Asian patients with NVAF remain undetermined. Objective: To determine risk factors for ischemic stroke in Japanese patients with NVAF. Design, Setting, and Participants: This cohort study analyzed individual patient data from 5 AF registries in Japan: J-RHYTHM (Japanese Rhythm Management Trial for Atrial Fibrillation) Registry, Fushimi AF Registry, Shinken Database, Keio Interhospital Cardiovascular Studies (Keio Study), and Hokuriku-Plus AF Registry. Patients with atrial fibrillation were registered from 158 institutions in the J-RHYTHM Registry, 80 in the Fushimi AF Registry, a single hospital in Shinken Database, 11 in the Keio Study, and 19 in the Hokuriku-Plus AF Registry. Patients with valvular AF or lacking data were excluded. Data were collected and integrated in March 2016, and those from the Keio Study were updated in April 2018. Data were analyzed from April 2018 to February 2020. Main Outcomes and Measures: Significant risk factors for ischemic stroke were determined by adjusted Cox proportional hazards analysis. Results: In total, 12 289 patients with NVAF (3758 [31%] female; mean [SD] age 70.2 [11] years) were analyzed with a mean (SD) follow-up period of 649 (181) days (1.8 [0.5] years). During 21 820 person-years of follow-up, 241 cases of ischemic stroke were reported. Risk factors associated with ischemic stroke after adjustment for oral anticoagulant use at enrollment were age (75-84 years: hazard ratio [HR], 1.74; 95% CI, 1.32-2.30; P < .001; and ≥85 years: HR, 2.41; 1.63-3.56; P < .001), hypertension (HR, 1.60; 95% CI, 1.15-2.23; P = .006), previous stroke (HR, 2.75; 95% CI, 2.09-3.62; P < .001), persistent or permanent AF (HR, 1.59; 95% CI, 1.21-2.10; P = .001), and body mass index less than 18.5 (HR, 1.55; 95% CI, 1.05-2.29; P = .03). Neither diabetes nor heart failure were identified as risk factors for ischemic stroke. Conclusions and Relevance: Previous stroke, advanced age, hypertension, persistent or permanent AF, and low body mass index were independent risk factors associated with ischemic stroke in Japanese patients with NVAF.