Mogashoa, Vanessa2024-11-182024-11-182024Mogashoa, Vanessa. (2024). Anticoagulation For Nonvalvular Atrial Fibrillation In South Africa [Master’s dissertation, University of the Witwatersrand, Johannesburg]. WireDSpace.https://hdl.handle.net/10539/42658https://hdl.handle.net/10539/42658A Research Report submitted in fulfillment of the requirements for the degree of Master of Medicine (Internal Medicine) to the Faculty of Health Sciences, School of Clinical Medicine, University of the Witwatersrand, Johannesburg 2024Background: Nonvalvular Atrial fibrillation (NVAF) is a growing epidemic in Africa. Anticoagulation, considered the backbone of NVAF management, is limited to warfarin as the mainstay of available anticoagulation therapy in most low-and-middle-income countries (LMICs). The optimal time in the therapeutic range (TTR) while on warfarin is crucial to avoid bleeding and thromboembolic complications. This study aimed to assess anticoagulation control in patients with NVAF on warfarin in Johannesburg, South Africa. Methods: We conducted a cross-sectional retrospective study on consecutive patients with NVAF managed between the 1st of January 2015 and the 31st of December 2019 at a tertiary- level academic centre in Johannesburg, South Africa. Anticoagulation control for patients with NVAF was assessed by calculating the time in therapeutic range using the Rosendaal method. Results: The study population comprised of 177 patients diagnosed with NVAF. The mean age in the study population was 65.0 ± 13.1 years. The median TTR among patients with NVAF was 46% [interquartile range (IQR): 8.7 – 86.0], and 63 (35.6%) patients with NVAF had a TTR ≥ 70%. Patients with poor anticoagulation control (TTR<70%) were on warfarin for a shorter duration compared with those with optimal anticoagulation control [56 days (IQR: 43 – 84) vs 70 days (IQR: 56 – 140), p=0.0013]. The mean CHA2DS2-VASc score was 4 ± 1.5, and it did not differ between patients with poor or optimal anticoagulation control. Among the 175 patients with calculable HAS-BLED scores, 21 (12.0%), 112 (64.0%) and 42 (24.0%) were at a low, moderate, and high risk for bleeding, respectively. Of the 21 patients in the HAS BLED low risk category, only 4 (19.0%) had a TTR<70% (p<0.001). Warfarin toxicity was documented in 13 (7.3%) patients. Conclusion: In our study, a TTR ≥ 70%, suggesting poor anticoagulation control was found in 35.6% of NVAF patients on warfarin. Larger multicentre trials comparing the occurrence of bleeding, thromboembolic events, as well as the total cost to the healthcare system in patients treated with warfarin compared to direct oral anticoagulation therapy are required to guide oral anticoagulation strategies in Africaen© 2024 University of the Witwatersrand, Johannesburg. All rights reserved. The copyright in this work vests in the University of the Witwatersrand, Johannesburg. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of University of the Witwatersrand, Johannesburg.Atrial fibrillationAnticoagulationWarfarinTime in therapeutic rangeDirect oral anticoagulantsInternational normalised ratioUCTDSDG-3: Good health and well-beingDissertationUniversity of the Witwatersrand, Johannesburg