Warfarin Nonadherence: What Factors Lead Patients with Afib to Discontinue?
Jennifer Barrett, Assistant Editor
Patients with atrial fibrillation (AF) frequently discontinue their warfarin therapy, and a recently-published study offers insight into factors that may contribute to nonadherence.
The report, released in JAMA Cardiology, focused on patients with AF who stopped warfarin treatment within a year, noting that certain AF procedures may be predictors for therapy discontinuation.
Patients with atrial fibrillation are typically prescribed warfarin to mitigate stroke risk, but warfarin’s interactions with other medications and foods can make it difficult for patients to maintain proper adherence. The study reaffirms that patients with AF who begin warfarin to prevent stroke are frequently nonadherent, but finds this to be especially apparent in patients who have undergone electrical cardioversion (ECV) or radiofrequency ablation (RFA).
Researchers at the University of Michigan studied warfarin therapy adherence in 734 patients with non-valvular AF between 2011 and 2013. Thirty six percent of patients discontinued warfarin therapy within a year. This included 54.1% of patients who underwent either ECV or RFA. Twenty nine percent of patients who did not undergo an AF procedure discontinued warfarin.
Further predictors of nonadherence noted in the study included lower CHA2DS2-VASc score and lower time in the therapeutic range in the first year.
Understanding reasons for warfarin discontinuation is important in taking the next steps to identify patients at risk for nonadherence and determine alternative treatments that may be better adhered to for stroke prevention, the researchers noted.
Barnes GD, Kaatz S, Lopez A. Discontinuation of warfarin therapy for patients with atrial fibrillation. JAMA Cardiol. 2017; doi: 10.1001/jamacardio.2016.5041