Open AccessIncidence of thromboembolic and bleeding events in patients with newly diagnosed nonvalvular atrial fibrillation: An Asian multicenter retrospective cohort study in Singapore
Author(s) -
Wee Xue Ting,
Ho Lih Maan,
Ho Han Kiat,
Lee Joyce YuChia,
Yap Chun Wei,
William Henry,
Chan Linus Chong En,
Tay Hooi Ching,
Goh Cynthia Eei Mei,
Tan Doreen SuYin
Publication year - 2017
Publication title -
clinical cardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.263
H-Index - 72
eISSN - 1932-8737
pISSN - 0160-9289
DOI - 10.1002/clc.22811
Subject(s) - medicine , warfarin , atrial fibrillation , hazard ratio , retrospective cohort study , stroke (engine) , bleed , incidence (geometry) , proportional hazards model , clinical endpoint , cohort , confidence interval , cohort study , surgery , randomized controlled trial , mechanical engineering , physics , optics , engineering
Background Real‐world effectiveness and safety of antithrombotics in nonvalvular atrial fibrillation (NVAF) patients in Singapore has not been thoroughly studied. Hypothesis. Users of various antithrombotics experience a significantly different risk of stroke and major bleed compared with warfarin users. Methods This multicenter retrospective cohort study included patients age ≥ 21 years newly diagnosed with NVAF between July 2012 and September 2015. Using electronic medical records, data on patients' demographics, antithrombotics prescribed, and CHA 2 DS 2 ‐VASc and HAS‐BLED risk factors were collected. Patients were followed for 1 year from diagnosis for the primary effectiveness and safety endpoints of incident stroke or systemic embolism and major bleed, respectively. The secondary safety endpoint was overall bleed. Hazard ratios (HR) were determined from Cox regression. Results Of 743 patients included, 224 were on warfarin, 156 on direct oral anticoagulants (DOACs), 277 on single antiplatelet therapy (SAPT), 28 on dual antiplatelet therapy (DAPT), and 58 on no therapy. Mean age (±SD) was 68.7 ± 13.0 years. Compared with warfarin users, SAPT (adjusted [adj.] HR: 3.70, 95% confidence interval [CI]: 1.21‐11.3) and DAPT users (adj. HR: 10.1, 95% CI: 1.51‐67.2) were more likely to develop thromboembolic outcomes. Also, DOAC users (adj. HR: 0.304, 95% CI: 0.158‐0.585), SAPT users (adj. HR: 0.142, 95% CI: 0.0680‐0.295), and DAPT users (adj. HR: 0.112, 95% CI: 0.0146‐0.857) were less likely to experience any bleed compared with warfarin users. Conclusions SAPT and DAPT are less effective than warfarin in NVAF patients. DOACs may be considered in view of lower risk of overall bleed.