Warfarin: time in therapeutic range, a single centre study on patients using warfarin for stroke prevention in non-valvular atrial fibrillation and prosthetic heart valves

Background: Warfarin remains the most commonly used oral anticoagulant (OAC) in Thailand for stroke prevention among patients with non-valvular atrial fibrillation (NVAF). The aim of this study was to investigate the relationship between time in therapeutic range (TTR) after warfarin initiation and clinical outcomes of NVAF. Methods: TTR was calculated by the Rosendaal method from international normalized ratio (INR) data acquired from a nationwide NVAF registry in Thailand. Patients were followed-up every six months. The association between TTR and clinical outcomes was analyzed. Results: There was a total of 2233 patients from 27 hospitals. The average age was 68.4 ± 10.6 years. The average TTR was 53.56 ± 26.37%. Rates of ischemic stroke/TIA, major bleeding, ICH, and death were 1.33, 2.48, 0.76, and 3.3 per 100 person-years, respectively. When patients with a TTR < 65% were compared with those with TTR ≥ 65%, the adjusted hazard ratios (aHR) for the increased risks of ischemic stroke/TIA, major bleeding, ICH, and death were 3.07, 1.90, 2.34, and 2.11, respectively. Conclusion: Poor TTR control is associated with adverse clinical outcomes in patients with NVAF who were on warfarin. Efforts to ensure good TTR (≥65%) after initiation of warfarin are mandatory to minimize the risk of adverse clinical outcomes.

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The 'single big cryoballoon' technique for acute pulmonary vein isolation in patients with paroxysmal atrial fibrillation: a prospective observational single centre study

European Heart Journal ◽

10.1093/eurheartj/ehn570 ◽

2008 ◽

Vol 30 (6) ◽

pp. 699-709 ◽

Cited By ~ 246

Author(s):

K.-R. J. Chun ◽

B. Schmidt ◽

A. Metzner ◽

R. Tilz ◽

T. Zerm ◽

...

Keyword(s):

Atrial Fibrillation ◽

Pulmonary Vein ◽

Pulmonary Vein Isolation ◽

Paroxysmal Atrial Fibrillation ◽

Single Centre ◽

Centre Study ◽

Single Centre Study

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Anticoagulation Control in Different Ethnic Groups Receiving Vitamin K Antagonist for Stroke Prevention in Atrial Fibrillation

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.736143 ◽

2021 ◽

Vol 8 ◽

Author(s):

Nur Azyyati Zawawi ◽

Izzati Abdul Halim Zaki ◽

Long Chiau Ming ◽

Hui Poh Goh ◽

Hanis Hanum Zulkifly

Keyword(s):

Atrial Fibrillation ◽

Clinical Outcome ◽

Ethnic Groups ◽

Therapeutic Range ◽

Stroke Prevention ◽

Warfarin Therapy ◽

Adverse Clinical Outcome ◽

Time In Therapeutic Range ◽

Anticoagulation Control

Vitamin K antagonist such as warfarin reduces the risk of stroke in atrial fibrillation (AF) patients. Since warfarin has a narrow therapeutic index, its administration needs to be regularly monitored to avoid any adverse clinical outcomes such as stroke and bleeding. The quality of anticoagulation control with warfarin therapy can be measured by using time in therapeutic range (TTR). This review focuses on the prevalence of AF, quality of anticoagulation control (TTR) and adverse clinical outcome in AF patients within different ethnic groups receiving warfarin therapy for stroke prevention. A literature search was conducted in Embase and PubMed using keywords of “prevalence,” “atrial fibrillation,” “stroke prevention,” “oral anticoagulants,” “warfarin,” “ethnicities,” “race” “time in therapeutic range,” “adverse clinical outcome,” “stroke, bleeding.” Articles published by 1st February 2020 were included. Forty-one studies were included in the final review consisting of AF prevalence (n = 14 studies), time in therapeutic range (n = 18 studies), adverse clinical outcome (n = 9 studies) within different ethnic groups. Findings indicate that higher prevalence of AF but better anticoagulation control among the Whites as compared to other ethnicities. Of note, non-whites had higher risk of strokes and bleeding outcomes while on warfarin therapy. Addressing disparities in prevention and healthcare resource allocation could potentially improve AF-related outcomes in minorities.

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