ACTIONABLE ATRIAL FIBRILLATION: WHEN DO I GET MY OAC?

Abstract

Atrial fibrillation (AF) is the most common heart dysrhythmia. AF is associated with an increase in the risk of ischemic stroke and this risk can be decreased by 2/3 with initiation of oral anticoagulation (OAC). AF is commonly diagnosed in the Emergency Department (ED) and we have previously suggested that ED Physicians (EDPs) play an important role in initiating OAC. Among patients with actionable AF (new or known AF in a patient who has an indication for OAC but is not taking it) who visit the ED, we sought to assess the impact of the speciality of the decision-making physician on the likelihood of receiving guideline-recommended therapy within 90 days of the ED visit. We also examined the impact of the prescribing physician on persistence of therapy at 6 months. This is a multi-hospital, retrospective cohort study of all patients who visited the ED of either a community, tertiary non-cardiac or tertiary cardiac hospital between September 1st, 2014 and May 30th, 2015 and had a discharge diagnosis of AF. Electronic and paper charts were examined to identify clinical characteristics, referral and prescription data. Patients were classified as either receiving a prescription from the EDP, referred to a specialist or assumed PCP (primary care provider) follow-up (in those with a registered PCP). Predictors of Canadian Cardiovascular Society (CCS) guideline-recommended anticoagulation at 90 days were analyzed using a multivariable logistic regression, adjusted for stroke and bleeding risk and new AF diagnosis. 788 patients were seen in the ED for AF. A total of 257 patients had actionable AF, 41% of which were new diagnoses. Mean CHADS2 score was 2+1. OAC prescription by the EDP independently predicted the likelihood of OAC fill within 90 days (OR 8.22, 95% CI 2.87-23.52, P < 0.001). Neither referral to a specialist nor PCP follow-up was associated with OAC initiation at 90 days. There was no difference in persistence of OAC in 6 months in patients receiving a prescription from the EDP as compared to patients receiving OAC from other physicians (74% versus 85%, respectively, P=0.36). Many patients attending the ED are diagnosed with actionable AF. An OAC prescription written by an EDP was predictive of filling a prescription within 90 days but the same was not true for patients with PCP follow-up or specialist referral. Rates of persistence of therapy for prescriptions initiated by the ERP are similar to those initiated by other physicians.