Such encounters may also serve as a sentinel event for those at high risk for stroke, facilitating important changes in their health behavior.Physicians can seize on such teachable moments to educate high-risk AF/FL patients on stroke risk and prevention and, when appropriate, to recommend or prescribe anticoagulation.Initiating anticoagulation at the time of ED discharge for stroke-prone patients does not increase bleeding rates and contributes to decreased mortality.Some patients, however, might prefer to have this shared decision-making conversation with a provider aware of their values and preferences, e.g., a primary care provider or cardiologist.Nevertheless, emergency physicians are an important link in the chain of multi-specialty care coordination for the stroke-prone AF/FL population—whether they initiate the discussion of thromboprophylaxis or actually prescribe anticoagulation.The initiation of thromboprophylaxis to ED patients with AF/FL at high risk for stroke has not been extensively studied. The literature that exists, however, demonstrates under-prescribing in countries around the world.The prescribing practices in U.S. community EDs, however, are not well understood. We undertook a multi-center, prospective, observational study to evaluate the anticoagulation practice patterns of community EPs and short-term, post-ED care providers in the management of patients with non-valvular AF/FL considered at high risk for ischemic stroke. We also sought to identify factors influencing initiation of oral anticoagulation. We hypothesized that increasing age, lack of cardiology involvement in the patient’s ED care, and restoration of sinus rhythm before ED discharge would decrease the likelihood of receiving an oral anticoagulant prescription. Lastly, we reviewed the electronic health records of the patients discharged without anticoagulation to evaluate documented reasons for withholding anticoagulation and provision of educational material on AF/FL stroke risk and prevention.
The source population was based within KPNC,planting table a large integrated healthcare delivery system that provides comprehensive medical care for four million members across 21 medical centers. KPNC members represent approximately 33% of the population in areas served and are highly representative of the local surrounding and statewide population. Emergency care was provided by emergency medicine residency-trained and board-certified EPs. During the study period , the annual census of each of the seven EDs ranged from 25,000 to 78,000. No departmental policies were in place at the participating EDs to govern the short-term anticoagulation management of patients with AF/FL. Patient care was left to the discretion of the treating EPs. All facilities had pharmacy services available around the-clock for discharge medications and supplemental patient education. Oral anticoagulation medications in use within KPNC during the study period were warfarin and dabigatran, warfarin being the drug of choice at the time. Furthermore, each facility had its own pharmacy-managed, phone-based Outpatient Anticoagulation Service that managed outpatient warfarin use and provided close follow-up and monitoring of these patients, akin to similar programs in other KP regions in the U.S.The percent time in therapeutic range for the international normalized ratio during the study period varied by facility and ranged from 70% to 74%, calculated with a six-month look-back period using the Rosendaal linear interpolation method.In the TAFFY study, adult KPNC health plan members in the ED with electrocardiographically-confirmed non-valvular AF/FL were eligible for prospective enrollment if their atrial dysrhythmia fell into any one of these three categories: symptomatic AF/FL; AF/FL requiring ED treatment for rate or rhythm control; or the first known electrocardiographically-documented episode of AF/FL. Patients were ineligible if they were transferred in from another ED, were receiving only palliative comfort care, had an implanted cardiac pacemaker/ defibrillator, or had been resuscitated from a cardiac arrest in the ED or just prior to arrival. The treating EPs enrolled patients via convenience sampling and were provided a small token of appreciation for their bedside data collection. No research assistants facilitated enrollment.
This anticoagulation study included TAFFY patients who were not taking oral anticoagulants at the time of ED presentation; at high risk for thromboembolic complications based on a validated thromboembolism risk score; and discharged home directly from the ED. Only a patient’s first enrollment was included in this analysis. We used the validated Anticoagulation and Risk Factors in Atrial Fibrillation stroke risk score to identify our AF/FL population at high risk for thromboembolism, as it has been shown to be more accurate than the CHADS2 or CHA2 DS2 -VASc stroke risk scores.TAFFY variables collected prospectively at the time of patient care included presenting symptoms; characterization of the atrial dysrhythmia ; comorbid diagnoses; ED management ; cardiology consultation; discharge rhythm and discharge pharmacotherapy. To minimize the effect that structured data collection might have on stroke prevention and to improve the odds of describing real-world behavior, the physician education material and data collection tool mentioned none of the following: hemorrhage risk, thromboembolic risk, risk scoring, indications for anticoagulation, post-ED follow-up care, or this study’s objectives and hypotheses. We undertook monthly manual chart review audits at each medical center to identify cases that were TAFFY-eligible but had not been enrolled to assess potential selection bias between the enrolled and missed-eligible populations. After completion of the enrollment period, we extracted additional demographic and clinical variables from the health system’s comprehensive integrated electronic health record. These included additional patient characteristics and oral anticoagulation prescription, prescriber,cannabis indoor grow system and outpatient follow-up within 30 days of ED discharge. Among 2,849 identified eligible patients, 1,980 were enrolled by the treating physicians in the parent TAFFY study. Enrolled and non-enrolled patients were comparable in terms of age, gender, comorbidity, and stroke risk scores, except that enrolled patients were more likely to have had a history of prior diagnosed AF/ FL.
For the present analysis, we excluded 906 enrolled patients who were not discharged home directly from the ED or were not KP health plan members at enrollment, 252 patients who were already taking anticoagulation therapy and 510 patients who were not high risk for thromboembolism. The remaining 312 AF/FL patients constituted our study cohort. While selected for the study based on their ATRIA score, all study patients were also found to be high risk using the CHA2 DS2 -VASc score.Overall, median age was 80 years , and 201 cohort members were women. Oral anticoagulants were prescribed to 128 patients within 30 days of the index ED visit, with 85 patients receiving a new anticoagulant prescription at the time of ED discharge and the remaining 43 patients in the following 30 days. In this sample, warfarin was the only oral anticoagulant prescribed. During the post ED-discharge period, the specialty of the physician prescribing anticoagulation included outpatient internal medicine , cardiology , hospital medicine , and emergency medicine. Among the 227 patients who left the ED without an oral anticoagulant prescription, 195 had an in-person or telephone encounter with a primary care provider or cardiologist within 30 days. Forty-three patients were discharged home only on antiplatelet medications: seven were advised to continue their daily aspirin and 36 were prescribed new daily antiplatelet agents at the time of discharge. Characteristics of the cohort stratified by anticoagulation initiation are described in Table 2. Variables independently associated with increased odds of anticoagulation initiation included younger age, new diagnosis of AF/FL, symptom onset >48 hours prior to evaluation, EP assessment of rhythm pattern as intermittent , receipt of cardiology consultation in the ED, and failure of sinus restoration by time of ED discharge. Among the 227 patients discharged home from the ED without anticoagulation, 139 patients had one or more reasons documented for withholding anticoagulation. These were categorized as physician concerns and patient concerns. The leading physician reasons for withholding anticoagulation were concerns about elevated bleeding risk , deferring the decision to an outpatient provider, and the perception that the restoration of sinus rhythm had significantly reduced or eliminated stroke risk. The leading patient reasons for declining anticoagulation were a preference to continue the discussion of anticoagulation with their outpatient provider and simple refusal, not otherwise specified. Deferring the shared decision-making process to the patient’s outpatient provider was the leading reason for withholding anticoagulation when combining physician and patient concerns. One hundred thirty-seven patients were given patient education material on AF/FL in their discharge instructions. The three versions of material used by the EPs each included one sentence about the general association between AF/FL and thromboembolic events. The material was not personalized, however, and did not quantify the patient’s specific risk , nor even mention broader thromboembolic risk categories , nor discuss the benefits and risks of stroke prevention therapy. Using an online random number generator , we identified 23 cases for review by a second abstractor. Percent agreement was the same for presence of both documented reason for non-prescribing and provision of patient education material.
The kappa statistic was 0.91 for each variable. In this multi-center, prospective cohort of non-anticoagulated AF/FL patients at high thromboembolic risk discharged home from the ED, we found that approximately 40% were prescribed oral anticoagulation within 30 days. Furthermore, we observed that younger age, selected rhythm-related characteristics in the ED, and receipt of cardiology consultation were strongly associated with receiving anticoagulation. About 60% of patients discharged home from the ED without anticoagulation had a reason documented in their electronic health record, a relatively high percentage of documentation compared with a recent, large, inpatient registry.The principal reason for non-prescribing in our study was deferring the shared decision-making process to the patient’s outpatient provider. Such reasoning is sensible in a setting like ours where patients have ready access to their outpatient physicians and 30-day follow-up is common.Our percentage of deferral was higher than in a similar study of ED anticoagulation prescribing for high-risk AF/FL in Spain , though, like our study population, all of their patients also had health coverage.Other leading documented reasons included a perception of increased bleeding risk and a perception of reduced stroke risk.The incidence of oral anticoagulation initiation for AF/FL patients at high risk for ischemic stroke who are discharged home from the ED has not been well described. Reports range widely, from approximately 10% to 50%. The calculation also varies depending on whether stroke-prone AF/FL patients deemed ineligible for anticoagulation are included in the denominator. A large, 124-center study from Spain by Coll-Vinent et al. in 2011 demonstrated that anticoagulation was initiated at the time of home discharge to 193 of 453 high-risk AF patients , higher than our 27%.The case mix in this study was similar to ours in that patients with all categories of AF were included , but was different in that they excluded patients thought ineligible for anticoagulation, something our study design did not allow. This difference might explain in part why their incidence of initiation was higher than what we observed. A more recent, 62-center Spanish study from the same investigators reported a similarly high incidence of de novo anticoagulation prescribing on ED discharge.32 Two hospitals with the University of British Columbia, Canada, have reported a high baseline incidence of appropriate anticoagulation initiation at ED discharge for high-risk AF/FL patients. As with the Spanish study above, these investigators had excluded ineligible patients.48 Other studies have reported lower incidences of anticoagulation initiation. A retrospective cohort study undertaken in 2008 in eight Canadian EDs observed thromboprophylaxis initiation in 21 of 210 patients with recent-onset AF/FL who were discharged home.A more recent prospective study by Stiell et al. described the treatment of patients with recent-onset AF at six academic Canadian EDs from 2010 to 2012 and found slightly lower rates of untreated high-risk patients leaving the ED with a new anticoagulation prescription.In a retrospective study of two academic Canadian EDs, Scheuermeyer et al reported that 27% of high-risk AF/FL patients were begun on appropriate stroke prevention medications at discharge, and documentation of reasons for withholding thromboprophylaxis was noted in an additional 21 patients.Our finding that older patients with high-risk AF/FL were less likely to receive an oral anticoagulant prescription than their younger counterparts is consistent with studies demonstrating under-treatment both in the ED and in other settings.Thromboprophylaxis is less commonly prescribed to patients over 75 years of age, even though this population likely benefits the most given their higher absolute risk of ischemic stroke compared with intracranial hemorrhage or life-threatening extracranial hemorrhage.Physicians often acknowledge their hesitancy to initiate anticoagulation in the elderly and very elderly,given that these patients often have a high comorbidity burden, associated cognitive disorders and polypharmacy-related challenges.