Warfarin Persistence in Nonvalvular Atrial Fibrillation

Study Questions:

What are the nonpersistence rates and associated factors for newly initiated warfarin therapy in Chinese patients with nonvalvular atrial fibrillation (AF)?

Methods:

From the Chinese Atrial Fibrillation Registry, 1,461 AF patients newly initiating warfarin between August 1, 2011 and June 30, 2014 were identified. The rate of warfarin discontinuation was estimated at 3 months, 1 year, and 2 years after therapy initiation using Kaplan-Meier analysis. Predictors of nonpersistence were assessed using multivariable Cox proportional hazard regression.

Results:

During 426 ± 232 days of follow-up, 22.1% of patients discontinued warfarin within 3 months, 44.4% within 1 year, and 57.6% within 2 years of therapy initiation. Patients with no or limited insurance coverage had a higher likelihood to discontinue warfarin than those with full insurance (adjusted hazard ratio [aHR], 1.65; 95% confidence interval [CI], 1.03-2.64 and aHR, 1.66; 95% CI, 1.13-2.42, respectively). Paroxysmal AF (aHR, 1.56; 95% CI, 1.28-1.92), no prior stroke/transient ischemic attack/thromboembolism (aHR, 1.60; 95% CI, 1.24-2.05), and no dyslipidemia (aHR, 1.34; 95% CI, 1.06-1.70) were independent predictors of warfarin nonpersistence.

Conclusions:

The authors concluded that warfarin nonpersistence is a significant problem for Chinese AF patients. They also concluded that specific factors can be used to identify at-risk patients for targeted interventions.

Perspective:

Using a multicenter registry from hospitals in Beijing, China, the authors describe the poor warfarin persistence among AF patients. Similar results have been seen in North American studies using both billing code and chart abstracted data (Circ Cardiovasc Qual Outcomes 2013;6:567-74 and Am Heart J 2014;168:487-94). These studies have reported mixed results for AF patients treated with direct oral anticoagulants as compared to warfarin therapy. As the authors of this manuscript note, targeted interventions to improve anticoagulant persistence are critically needed in order to prevent stroke and thromboembolism.

Keywords: Anticoagulants, Arrhythmias, Cardiac, Atrial Fibrillation, Dyslipidemias, Insurance Coverage, Ischemic Attack, Transient, Primary Prevention, Stroke, Thromboembolism, Warfarin, Vascular Diseases


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