Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Sep 26, 2021; 13(9): 483-492
Published online Sep 26, 2021. doi: 10.4330/wjc.v13.i9.483
Patients’ time in therapeutic range on warfarin among atrial fibrillation patients in Warfarin Medication Therapy Adherence Clinic
Siew Ling Lee, Thien Jian Ong, Wardati Mazlan-Kepli, Annuysia Mageswaran, Kai Hsin Tan, Abdul-Muizz Abd-Malek, Robert Cronshaw
Siew Ling Lee, Thien Jian Ong, Wardati Mazlan-Kepli, Annuysia Mageswaran, Kai Hsin Tan, Department of Pharmacy, Hospital Serdang, Ministry of Health Malaysia, Kajang 43000, Selangor, Malaysia
Abdul-Muizz Abd-Malek, Department of Cardiology, Hospital Serdang, Ministry of Health Malaysia, Kajang 43000, Selangor, Malaysia
Robert Cronshaw, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G128QQ, United Kingdom
Author contributions: Mazlan-Kepli W contributed to the idea and study design; Siew-Ling L, Thien-Jian O, and Annuysia M contributed to and performed all data analyses and interpretation of results; Siew-Ling L and Thien-Jian O wrote the first manuscript; Wardati MK contributed to the interpretation of results and critically reviewed the final manuscript; All authors contributed to the review of an approved manuscript before submission.
Institutional review board statement: Ethical approval for this study was obtained from the Medical Research and Ethics Committee (MREC), Ministry of Health Malaysia (NMRR-19-839-46462).
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment. Permission to use the patient data from this facility has been obtained from the Head of Department of Cardiology, Hospital Serdang.
Conflict-of-interest statement: The authors have no financial relationships to disclose.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Siew Ling Lee, BPharm, Pharmacist, Department of Pharmacy, Hospital Serdang, Ministry of Health Malaysia, Jalan Puchong, Kajang 43000, Selangor, Malaysia.
Received: March 10, 2021
Peer-review started: March 10, 2021
First decision: May 6, 2021
Revised: May 25, 2021
Accepted: July 26, 2021
Article in press: July 26, 2021
Published online: September 26, 2021
Research background

The time in therapeutic range (TTR) is a quality measure for anticoagulation therapy with warfarin.

Research motivation

TTR of international normalized ratio (INR) needs to be achieved with a percentage of ≥ 60% for patient to receive a maximal benefit from warfarin such as preventing stroke, major bleeding, and even death.

Research objectives

TTR and the predictors of poor TTR need to be evaluated among atrial fibrillation (AF) patients that received warfarin therapy.

Research methods

Eligible patients with AF from January 2014 to December 2018 for INR monitoring were included in this study. Demographic data, indication of warfarin therapy, INR target, and percentage of INR within range were collected using a data collection form. TTR was assessed using Rosendaal method.

Research results

In patients with AF, the mean TTR was 60.6% with the highest TTR score achieved in 2018, with a percentage of 67.3%.

Research conclusions

This study showed that high HAS-BLED score was associated to poor TTR.

Research perspectives

Patients with AF and high HAS-BLED score may have less benefit from warfarin therapy. Thus, other alternative oral anticoagulants should be considered for maximum benefit.