Average Systolic Blood Pressure and Clinical Outcomes in Patients with Atrial Fibrillation: Prospective Data from COOL-AF Registry

Rungroj Krittayaphong,1 Satchana Pumprueg,1 Kasem Ratanasumawong,2 Poom Sairat,1 Gregory YH Lip3,4 On behalf of the COOL-AF Investigators1Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand; 2Police General Hospital, Bangkok, Thailand; 3Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart & Chest Hospital, Liverpool, UK; 4Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, DenmarkCorrespondence: Rungroj KrittayaphongDivision of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, ThailandTel +66 2-419-6104Email rungroj.kri@mahidol.ac.thPurpose: Hypertension is associated with incident atrial fibrillation (AF) and AF-related complications. We investigated the associations between average systolic blood pressure (SBP) and outcomes in a nationwide cohort of Asian patients with non-valvular atrial fibrillation (NVAF).Patients and Methods: A multicenter nationwide registry of patients with NVAF in Thailand was conducted during 2014– 2017. Clinical data, including blood pressure, were recorded at baseline and then every 6 months. Average SBP was calculated from the average of SBP from every visit. Cox regression models were used to calculate the rate of clinical outcomes of interest, ie ischemic stroke or transient ischemic attack (TIA), intracerebral hemorrhage (ICH), and all-cause death. Average SBP was categorized into three groups: < 120, 120– 140, and ≥ 140 mmHg.Results: A total of 3402 patients were included, and the mean age was 67.4± 11.3 years. The mean (±SD) baseline and average SBPs were 128.5± 18.5 and 128.0± 13.4 mmHg, respectively. The mean follow-up duration was 25.7± 10.6 months. The median rate of ischemic stroke/TIA, ICH, and all-cause death was 1.43 (1.17– 1.74), 0.70 (0.52– 0.92), and 3.77 (3.33– 4.24) per 100 person-years, respectively. The rate of ischemic stroke/TIA and ICH was lowest in patients with average SBP < 120 mmHg, and highest among those with average SBP ≥ 140 mmHg. The death rates were consistent with a J-curve effect, being lowest in patients with an average SBP 120– 140 mmHg. Sustained SBP control is more important than the SBP from a single visit.Conclusion: Sustained control of SBP was significantly associated with a reduction in adverse clinical outcomes in patients with NVAF.Keywords: atrial fibrillation, ischemic stroke, intracerebral hemorrhage, blood pressure, hypertension