The relationship between diastolic blood pressure and the risk of cardiovascular events in patients with atrial fibrillation: the Fushimi AF registry

Abstract

Abstract Background Hypertension is one of the major risk factors of cardiovascular events in patients with atrial fibrillation (AF). However, relationship between diastolic blood pressure (DBP) and cardiovascular events in AF patients remains unclear. Methods The Fushimi AF Registry is a community-based prospective survey of AF patients in Japan. Follow-up data were available in 4,466 patients, and 4,429 patients with available data of DBP were examined. We divided the patients into three groups; G1 (DBP<70 mmHg, n=1,946), G2 (70≤DBP<80, n=1,321) and G3 (80≤DBP, n=1,162), and compared the clinical background and outcomes between groups. Results The proportion of female was grater in G1 group, and the patients in G1 group were older and had higher prevalence of heart failure (HF), diabetes mellitus (DM), chronic kidney disease (CKD). Prescription of beta blockers was higher in G1 group, but that of renin-angiotensin system-inhibitors and calcium channel blocker was comparable. During the median follow-up of 1,589 days, in Kaplan-Meier analysis, the incidence rates of cardiovascular events (composite of cardiac death, ischemic stroke and systemic embolism, major bleeding and HF hospitalization during follow up) were higher in G1 group and G3 group than G2 group (Figure 1). When we divided the patients based on the systolic blood pressure (SBP) at baseline (≥130 mmHg or <130 mmHg), the incidence of rates of cardiovascular events were comparable among groups. Multivariate Cox proportional hazards regression analysis including female gender, age (≥75 years), higher SBP (≥130 mmHg), DM, pre-existing HF, CKD, low left ventricular ejection fraction (<40%) and DBP (G1, G2, G3) revealed that DBP was an independent determinant of cardiovascular events (G1 group vs. G2 group; hazard ratio (HR): 1.40, 95% confidence intervals (CI): 1.19–1.64, G3 group vs. G2 group; HR: 1.23, 95% CI: 1.01–1.49). When we examined the impact of DBP according to 10 mmHg increment, patients with very low DBP (<60 mmHg) (HR: 1.50,95% CI:1.24–1.80) and very high DBP (≥90 mmHg) (HR: 1.51,95% CI:1.15–1.98) had higher incidence of cardiovascular events than patients with DBP of 70–79 mmHg (Figure 2). However, when we examined the impact of SBP according to 20 mmHg increment, SBP at baseline was not associated with the incidence of cardiovascular events (Figure 3). Conclusion In Japanese patients with AF, DBP exhibited J curve association with higher incidence of cardiovascular events. Funding Acknowledgement Type of funding source: None