Association of systolic blood pressure with atrial fibrillation among treated hypertensive patients

Background: Although many studies have suggested the association between elevated blood pressure and atrial fibrillation (AF), how the relationship between systolic blood pressure (SBP) and AF differ by antihypertensive treatment has been unclear. Therefore, this study aimed to explore the relationship between SBP and AF in hypertensive patients with or without antihypertensive treatment. Methods: This was a cross-sectional study that enrolled 7,808 hypertensive patients aged >= 18 years old in 2013 in Guangdong, China. AF was screened and diagnosed by rest 12-lead electrocardiogram (ECG) or by self-reported. Patients were categorized into 5 groups according to a 10 mmHg increment in SBP. We then performed logistic regression and restricted cubic spline regression to evaluate the relationship between SBP and AF. Results: Out of 7,808 participants (women 52.9%, mean age 62.3 years), 78 cases of AF were identified. Both univariate and multivariate logistic regression illustrated that SBP associated with a lower chance of AF in all participants when SBP was treated as a continuous variable (P<0.05) or as a categorical variable (P for trend <0.001). Similar trend was found in patients with antihypertensive therapy (P for trend <0.001) but not for those without antihypertensive medications. Conclusions: Our findings suggested that higher SBP is associated with lower likelihood of AF among all hypertensive patients and participants with antihypertensive treatment.