Jo-Nan Liao1, Tze-Fan Chao1, Chia-Jen Liu2, Su-Jung Chen3, Chung-Lieh Hung4, Yenn-Jiang Lin1, Shih-Lin Chang1, Li-Wei Lo1, Yu-Feng Hu1, Ta-Chuan Tuan1, Fa-Po Chung1, Tzeng-Ji Chen5, Gregory Y H Lip6, Shih-Ann Chen7. 1. Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan. 2. Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Public Health and School of Medicine, National Yang-Ming University, Taipei, Taiwan. 3. Institute of Public Health and School of Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan. 4. Institute of Clinical Medicine and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan; Division of Cardiology, Departments of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan; Medical Research, MacKay Memorial Hospital, New Taipei City, Taiwan; Department of Medicine, MacKay Medical College, New Taipei City, Taiwan; MacKay Junior College of Medicine, Nursing and Management, New Taipei City, Taiwan. 5. Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan. 6. University of Birmingham Institute of Cardiovascular Sciences, City Hospital, Birmingham, United Kingdom. 7. Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Institute of Clinical Medicine and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan. Electronic address: epsachen@ms41.hinet.net.
Abstract
BACKGROUND: Several cardiovascular diseases exhibit seasonal variations, but data about cold temperature and risk of ischemic stroke in patients with atrial fibrillation (AF) are limited. OBJECTIVE: The purpose of this study was to investigate the risk of ischemic stroke in different seasons, testing the hypothesis that the cold weather season would increase the risk of stroke in AF. METHODS: This study used the National Health Insurance Research Database in Taiwan. From 2000 to 2012, a total of 289,559 AF patients were enrolled, and 34,991 experienced ischemic stroke after mean follow-up of 3 years. The relationship between risk of ischemic stroke and temperatures was analyzed. RESULTS: The highest incidence of ischemic stroke was observed in winter, which was the coldest season, with an incidence rate of 0.33 per 100 person-months. Compared with the summer period, the risk of ischemic stroke increased by 10% in spring (incidence rate ratio [IRR] 1.10; 95% confidence interval [CI] 1.07-1.13) and by 19% in winter (IRR 1.19; 95% CI 1.15-1.22) but did not differ significantly between summer and autumn (IRR 1.00; 95% CI 0.97-1.03). Compared with the days with an average temperature of 30°C, the risk of ischemic stroke for days with an average temperature <20°C significantly increased. Lower 7-, 10-, or 14-day average temperatures were significantly associated with an increased risk of ischemic stroke in the case-crossover analysis. CONCLUSION: In this nationwide study, a seasonal variation of incidence of ischemic stroke in AF patients was observed, with an increased risk of stroke on days with an average temperature <20°C. AF-related stroke may be influenced by environmental interactions.
BACKGROUND: Several cardiovascular diseases exhibit seasonal variations, but data about cold temperature and risk of ischemic stroke in patients with atrial fibrillation (AF) are limited. OBJECTIVE: The purpose of this study was to investigate the risk of ischemic stroke in different seasons, testing the hypothesis that the cold weather season would increase the risk of stroke in AF. METHODS: This study used the National Health Insurance Research Database in Taiwan. From 2000 to 2012, a total of 289,559 AFpatients were enrolled, and 34,991 experienced ischemic stroke after mean follow-up of 3 years. The relationship between risk of ischemic stroke and temperatures was analyzed. RESULTS: The highest incidence of ischemic stroke was observed in winter, which was the coldest season, with an incidence rate of 0.33 per 100 person-months. Compared with the summer period, the risk of ischemic stroke increased by 10% in spring (incidence rate ratio [IRR] 1.10; 95% confidence interval [CI] 1.07-1.13) and by 19% in winter (IRR 1.19; 95% CI 1.15-1.22) but did not differ significantly between summer and autumn (IRR 1.00; 95% CI 0.97-1.03). Compared with the days with an average temperature of 30°C, the risk of ischemic stroke for days with an average temperature <20°C significantly increased. Lower 7-, 10-, or 14-day average temperatures were significantly associated with an increased risk of ischemic stroke in the case-crossover analysis. CONCLUSION: In this nationwide study, a seasonal variation of incidence of ischemic stroke in AFpatients was observed, with an increased risk of stroke on days with an average temperature <20°C. AF-related stroke may be influenced by environmental interactions.
Authors: Philipp Bücke; Hans Henkes; Guy Arnold; Birgit Herting; Eric Jüttler; Christof Klötzsch; Alfred Lindner; Uwe Mauz; Ludwig Niehaus; Matthias Reinhard; Stefan Waibel; Thomas Horvath; Hansjörg Bäzner; Marta Aguilar Pérez Journal: Eur J Neurol Date: 2021-05-05 Impact factor: 6.288