Abstract
BACKGROUND AND AIMS: This study aimed to investigate the association between normal BP, (blood pressure [BP] 120-129/80-84 mmHg), and high normal BP, (BP 130-139/85-89 mmHg), compared to optimal BP, and risk of atrial fibrillation (AF). METHODS: A population-based cohort study was performed including inhabitants of Västerbotten County, Sweden, aged 30-60 years without AF at inclusion who participated in health examinations in 1988-2014. Approximately 40% of participants had ≥ 2 health examinations. The health examination included a questionnaire and measurement of BP, weight, height, and glucose. Cox regression with time-updated covariates was used to estimate the association between BP and AF risk. Restricted cubic spline analyses were performed. RESULTS: The cohort included 109,697 persons with 162,982 observations and a mean follow-up of 13.6 years. Incident AF was diagnosed in 5260 participants. We found an increased risk of incident AF associated with normal BP (hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.01-1.27) and high normal BP (HR 1.23, 95% CI 1.10-1.38) compared to optimal BP after multivariable adjustment. Systolic BP and diastolic BP in 10 mmHg increments were associated with risk of incident AF, with HRs of 1.11 (95% CI 1.10-1.13) and 1.13 (95% CI 1.09-1.16), respectively, in multivariable models. A restricted cubic spline analysis indicated that the AF risk increased gradually with increasing systolic and diastolic BP. CONCLUSION: Individuals with both normal BP and high normal BP have an increased risk of developing incident AF. The risk of AF increased gradually with increasing systolic and diastolic BP.