Insurance coverage and prior stroke or ischemic attack predicted nonpersistence of warfarin therapy among Chinese patients with nonvalvular atrial fibrillation (AF), according to data recently published in Circulation: Cardiovascular Quality and Outcomes.
Warfarin is widely recommended for the prevention of ischemic stroke among patients with nonvalvular AF, however the factors that cause nonpersistence in warfarin treatment are still unknown.
Zhi-Zun Wang, MD, and colleagues, from the Department of Cardiology at Beijing Anzhen Hospital, Capital Medical University and National Clinical Research Center for Cardiovascular Diseases, measured nonpersistence rates of warfarin treatment in 1461 Chinese patients with nonvalvular AF in order to determine the factors associated with treatment discontinuation.
“Nonpersistence of warfarin treatment has been recognized as one of the major barriers for its efficacy improvement,” researchers wrote. “Furthermore, we found that no or partial health insurance coverage, paroxysmal AF, no prior stroke/TIA/thromboembolism , and no dyslipidemia were predictive for nonpersistence of warfarin use.”
They identified patients with nonvalvular AF who were enrolled in the Chinese Atrial Fibrillation Registry who had newly started warfarin therapy between August 2011 and June 2014. The patients were followed for an average follow-up period of 426 ± 232 days.
During the follow-up period, 22.1% of patients discontinued warfarin within 3 months after the initiation of therapy, 44.4% discontinued treatment within 1 year, and 57.6% discontinued treatment within 2 years.
Patients who had no or partial insurance coverage were more likely to discontinue warfarin therapy (adjusted hazard ratio [HR]: 1.65; 95% confidence interval [CI]: 1.03-2.64; P=.038) compared with those with full insurance coverage (adjusted HR: 1.66; 95% CI: 1.13-2.42; P=.009).
In addition, researchers found that paroxysmal AF (adjusted HR: 1.56; 95% CI: 1.28-1.92; P<.0001), no prior stroke, transient ischemic attack, or thromboembolism (adjusted HR: 1.60; 95% CI: 1.24-2.05; P=.0003), and no dyslipidemia (adjusted HR: 1.34; 95% CI: 1.06-1.70; P=.016) were independent predictors for nonpersistence of warfarin therapy.
Although prior studies have indicated that younger age (<65 years) and male patients are more likely to discontinue warfarin, the current study found that age, sex, and CHA2DS2-VASc score did not have an impact on long-term persistence to warfarin therapy in this patient population.
“The high incidence of nonpersistence of warfarin therapy becomes another outstanding problem in the management of AF in China,” the authors wrote. “Our findings can be used to identify patients who require closer attention or to develop better management strategy to maximize benefit and minimize harm from oral anticoagulation therapy.”
Disclosures: Dr Ma has received honoraria from Bristol-Myers Squibb, Pfizer, Johnson & Johnson, Boehringer-Ingelheim, and Bayer. Dr Dong has also received honoraria from Johnson & Johnson.
Wang ZZ, Du X, Wang W, et al. Long-term persistence of newly initiated warfarin therapy in Chinese patients with nonvalvular atrial fibrillation. Circ Cardiovasc Qual Outcomes. 2016. doi: 10.1161/circoutcomes.115.002337.