Risk of stroke and heart failure attributable to atrial fibrillation in middle-aged and elderly people: Results from a five-year prospective cohort study of Japanese community dwellers

Masaki Ohsawa; Tomonori Okamura; Kozo Tanno; Kuniaki Ogasawara; Kazuyoshi Itai; Yuki Yonekura; Kazuki Konishi; Shinichi Omama; Naomi Miyamatsu; Tanvir Chowdhury Turin; Yoshihiro Morino; Tomonori Itoh; Toshiyuki Onoda; Kiyomi Sakata; Yasuhiro Ishibashi; Shinji Makita; Motoyuki Nakamura; Fumitaka Tanaka; Toru Kuribayashi; Mutsuko Ohta; Akira Okayama

doi:10.1016/j.je.2016.08.012

Risk of stroke and heart failure attributable to atrial fibrillation in middle-aged and elderly people: Results from a five-year prospective cohort study of Japanese community dwellers

J Epidemiol. 2017 Aug;27(8):360-367. doi: 10.1016/j.je.2016.08.012. Epub 2017 Apr 5.

Authors

Masaki Ohsawa¹, Tomonori Okamura², Kozo Tanno³, Kuniaki Ogasawara⁴, Kazuyoshi Itai⁵, Yuki Yonekura³, Kazuki Konishi⁶, Shinichi Omama⁴, Naomi Miyamatsu⁷, Tanvir Chowdhury Turin⁸, Yoshihiro Morino⁹, Tomonori Itoh⁹, Toshiyuki Onoda³, Kiyomi Sakata³, Yasuhiro Ishibashi⁹, Shinji Makita⁹, Motoyuki Nakamura⁹, Fumitaka Tanaka⁹, Toru Kuribayashi¹⁰, Mutsuko Ohta¹¹, Akira Okayama¹²

Affiliations

¹ Department of Internal Medicine, Iwate Medical University, Morioka, Japan; Department of Internal Medicine, Morioka Tsunagi Onsen Hospital, Morioka, Japan. Electronic address: m-ohsawa@k2.dion.ne.jp.
² Department of Preventive Medicine and Public Health, Keio University, Tokyo, Japan.
³ Department of Hygiene and Preventive Medicine, Iwate Medical University, Yahaba-cho, Iwate, Japan.
⁴ Department of Neurosurgery, Iwate Medical University, Morioka, Japan.
⁵ Department of Nutritional Sciences, Morioka University, Takizawa, Iwate, Japan.
⁶ Department of Internal Medicine, Morioka Tsunagi Onsen Hospital, Morioka, Japan.
⁷ Department of Clinical Nursing, Shiga University of Medical Science, Otsu, Japan.
⁸ Department of Community Health Sciences, University of Calgary, Calgary, Canada.
⁹ Department of Internal Medicine, Iwate Medical University, Morioka, Japan.
¹⁰ Department of Health and Physical Education, Faculty of Education, Iwate University, Morioka, Japan.
¹¹ Iwate Health Service Association, Morioka, Japan.
¹² The Research Institute of Strategy for Prevention, Tokyo, Japan.

Abstract

Background: The relative and absolute risks of stroke and heart failure attributable to atrial fibrillation (AF) have not been sufficiently examined.

Methods: A prospective study of 23,731 community-dwelling Japanese individuals was conducted. Participants were divided into two groups based on the presence or absence of prevalent AF (n = 338 and n = 23,393, respectively). Excess events (EE) due to AF and relative risks (RRs) determined using the non-AF group as the reference for incident stroke and heart failure were estimated using Poisson regression stratified by age groups (middle-aged: 40-69 years old; elderly: 70 years of age or older) after adjustment for sex and age.

Results: There were 611 cases of stroke and 98 cases of heart failure during the observation period (131,088 person-years). AF contributed to a higher risk of stroke both in middle-aged individuals (EE 10.4 per 1000 person-years; RR 4.88; 95% confidence interval [CI], 2.88-8.29) and elderly individuals (EE 18.3 per 1000 person-years; RR 3.05; 95% CI, 2.05-4.54). AF also contributed to a higher risk of heart failure in middle-aged individuals (EE 3.7 per 1000 person-years; RR 8.18; 95% CI, 2.41-27.8) and elderly individuals (EE 15.4 per 1000 person-years; RR 7.82; 95% CI, 4.11-14.9). Results obtained from multivariate-adjusted analysis were similar (stroke: EE 8.9 per 1000 person-years; RR 4.40; 95% CI, 2.57-7.55 in middle-aged and EE 17.4 per 1000 person-years; RR 2.97; 95% CI, 1.99-4.43 in elderly individuals; heart failure: EE 3.1 per 1000 person-years; RR 7.22; 95% CI, 2.06-25.3 in middle-aged and EE 14.1 per 1000 person-years; RR 7.41; 95% CI, 3.86-14.2 in elderly individuals).

Conclusions: AF increased the risk of stroke by the same magnitude as that reported previously in Western countries. AF increased the RR of heart failure more than that in Western populations.

Keywords: Absolute risk; Atrial fibrillation; Heart failure; Prospective study; Relative risk; Stroke.

MeSH terms

Adult
Aged
Atrial Fibrillation / complications*
Female
Heart Failure / epidemiology*
Humans
Independent Living
Japan / epidemiology
Male
Middle Aged
Multivariate Analysis
Prevalence
Prospective Studies
Risk
Stroke / epidemiology*