A prospective study on the association between atrial fibrillation and blood pressure in an elderly Chinese population

Abstract

Background: Intensive blood pressure (BP) lowering in patients with hypertension has been associated with a lowered risk of atrial fibrillation (AF). It is still uncertain what is the optimal BP levels to prevent AF in the general elderly population. In the present prospective study, we investigated the association between incident AF and BP in an elderly Chinese population.

Methods and findings: Elderly (≥65 years) residents were recruited from 6 communities in Shanghai. 9019 participants who did not have AF at baseline and had at least one ECG recording during follow-up were included in the present analysis. During a median of 3.5 years follow-up, the overall incidence rate of AF was 5.6 per 1000 person-years (n = 178). Systolic BP was associated with increased AF risk (age- and sex-adjusted hazard ratio [HR] per 20-mmHg increase for systolic BP 1.21, 95% CI 1.04-1.39, P = 0.01), but risk estimate was attenuated after adjustment for common AF risk factors. In categorical analyses, statistical significance was achieved for HR relative to optimal BP only in stage 2 or 3 systolic and diastolic hypertension (multivariate-adjusted HR 1.76, 95% CI 1.00-3.08, P = 0.05). The association between AF incidence and BP status tended to be stronger in the absence than presence of a history of cardiovascular disease at baseline (P for interaction = 0.06).

Conclusion: In this Chinese population of 65 years and older, linear increases in systolic and diastolic BP were not independently associated with increased risk of AF, and only exposure to stage 2 or 3 hypertension carries a higher risk of AF.

Keywords: Atrial fibrillation; Blood pressure; Elderly; Hypertension.