Aim: The association between atrial fibrillation (AF) and risk of stroke mortality among men and women without traditional cerebrocardiovascular risk factors (TCVRFs) is unclear. This study aimed to determine whether AF was a risk factor for stroke and total cardiovascular disease mortality among individuals without TCVRFs.
Methods: A total of 90,629 Japanese subjects from the Ibaraki Prefectural Health Study aged 40-79 years, with and without TCVRFs, were studied from 1993 to 2013. Hazard ratios (HRs) were calculated using the Cox proportional hazard regression model stratified by sex and the presence of TCVRFs. Covariates were age, systolic blood pressure, anti-hypertensive medication use, and serum total cholesterol levels. A standard 12-lead electrocardiogram at rest was used to screen AF. Cause-specific mortality was classified according to the International Classification of Disease code.
Results: Compared with participants without AF, multivariable-adjusted hazard ratios (with 95% confidence intervals) for stroke mortality among participants without TCVRFs were 4.3 (1.1-17.8) and 15.0 (5.5-40.8) for men and women with AF, respectively. HRs for total cardiovascular disease mortality were 6.2 (2.8-14.2) for men and 10.7 (4.8-24.1) for women. For participants with TCVRFs, multivariable-adjusted HRs for stroke mortality were 3.1 (2.2-4.6) and 4.3 (2.6-7.3), whereas HRs for total cardiovascular disease mortality were 2.9 (2.2-3.8) and 3.5 (2.4-5.1) for men and women, respectively.
Conclusions: AF was found to be an independent risk factor for stroke and total cardiovascular mortality even in individuals without other TCVRFs.
Keywords: Atrial fibrillation; Cardiovascular disease; Cohort studies; Stroke.