Impact of baseline blood pressure on all-cause mortality in patients with atrial fibrillation: results from a multicenter registry study

Abstract Background: The ideal blood pressure (BP) target for patients with atrial fibrillation (AF) is still unclear. The present study aimed to assess the effect of the baseline BP on all-cause mortality in patients with AF. Methods: This registry study included 20 emergency centers across China and consecutively enrolled patients with AF from 2008 to 2011. All participants were followed for 1 year ± 1 month. The primary endpoint was all-cause mortality. Results: During the follow-up, 276 (13.9%) all-cause deaths occurred. Kaplan–Meier curves showed that a systolic blood pressure (SBP) ≤110 mmHg or >160 mmHg was associated with a higher risk of all-cause mortality (log-rank test, P = 0.014), and a diastolic blood pressure (DBP) <70 mmHg was associated with the highest risk of all-cause mortality (log-rank test, P = 0.002). After adjusting for confounders, the multivariable Cox regression model suggested that the risk of all-cause mortality was increased in the group with SBP ≤110 mmHg (hazard ratio [HR], 1.963; 95% confidence interval [CI], 1.306–2.951), and DBP <70 mmHg (HR, 1.628; 95% CI, 1.163–2.281). In the restricted cubic splines, relations between baseline SBP or DBP and all-cause mortality showed J-shaped associations (non-linear P <0.001 and P = 0.010, respectively). The risk of all-cause mortality notably increased at a lower baseline SBP and DBP. Conclusions: Having a baseline SBP ≤110 mmHg or DBP <70 mmHg was associated with a significantly higher risk of all-cause mortality in patients with AF. An excessively low BP may not be an optimal target for patients with AF.