Only 1 in 5 With High-Risk AF Leave ED on Anticoagulant

Damian McNamara

May 17, 2019

PHILADELPHIA — People with atrial fibrillation (AF) who underwent treatment and were discharged directly from one of three emergency departments (EDs) in South Florida were much less likely to receive a prescription for an oral anticoagulant compared to patients who were admitted for observation or for inpatient care, a new study shows.

The disparity emerged from a review of charts for 436 people with AF who underwent treatment in the Jackson Health System in Miami during a 4-year period.

"What was most striking is that only 17.5% of these patients in the ED group were discharged on an anticoagulant, compared to 73% of the observation group and 80% of the inpatient group," lead author Hope Hua, a medical student at the University of Miami Miller School of Medicine, which is affiliated with the Jackson Health System, said here at the American Academy of Neurology (AAN) 2019 Annual Meeting.

In general, attributable risk for stroke from AF is estimated to be 1.5% for people in their 50s; the rate climbs to nearly 30% for those aged 80 to 89 years.

"This increased risk for stroke can be diminished with use of an anticoagulant," Hua said. Overall, fewer than 50% of high-risk patients are taking an oral anticoagulant, she added. For those with AF who experience an acute ischemic stroke, use of anticoagulation therapy is often inadequate preceding the stroke.

Hua and colleagues compared management of 105 people with AF who were discharged directly from the ED, 131 who were admitted for observation and discharged within 48 hours, and 200 who were admitted to inpatient care. All participants were seen in the ED between January 1, 2014, and January 1, 2018, and were discharged with AF as their primary diagnosis.

The average age of patients in the ED and observation groups was 62 years; the average age of patients in the inpatient cohort was 65 years. Of the study population, 46% were women; 78% of those studied had hypertension. A large number of patients in the inpatient group had a history of heart failure, previous myocardial infarction, coronary artery disease, or diabetes.

The investigators considered those with a CHA2DS2-VASc score of 2 or greater as being at high risk for a thromboembolic event. The average CHA2DS2-VASc score was 2.45 in the ED cohort, 2.56 in the observation group, and 3.35 among those admitted for inpatient care.

Within the ED group, the researchers found that 68 of 105 patients had not been taking an anticoagulant prior to their ED visit. Of those 68 patients, 40 were at high risk.

"So it seems that anticoagulants are vastly underutilized in patients that would significantly benefit from their use," Hua said.

The lower percentage of people in the ED group who were prescribed oral anticoagulation was statistically significant compared to rates in the other two cohorts (P < .0001).

The investigators also examined charts to determine the type of provider in each case. "About 100% of the observation and inpatient group patients had a cardiologist or internist involved in their care," Hua said. "This seems to have contributed to a much higher anticoagulant prescription rate.

"Something else that was also concerning was that 77% of high-risk patients were educated about their AF by an ED physician, but of these patients, only 22% were started on anticoagulation," Hua said.

Suggestions for Improvement

"A 'golden opportunity' exists to start AF patients in the ED on anticoagulation," she said.

Education of emergency physicians to heighten awareness and potentially increase anticoagulant prescription rates is one possible solution, Hua said. Electronic medical record reminders might also help.

"Also, incorporation of ED pharmacists to care teams might help make ED physicians feel more comfortable in prescribing anticoagulants," she added.

Session co-moderator Jennifer Majersik, MD, chief of the Division of Vascular Neurology and associate professor of neurology at the University of Utah School of Medicine in Salt Lake City, emphasized the importance of prescribing an anticoagulant to AF patients at discharge only when there are firm plans for immediate follow-up with a primary care physician or stroke specialist.

Hua said that in future research, she and colleagues would like to evaluate the effect of referrals to an anticoagulation clinic or specialized stroke clinic on treatment adherence and outcomes.

Professional societies have weighed in on the prescription of oral anticoagulants. "The ED represents an important location to identify patients with new-onset AF, to initiate anticoagulation depending on comorbidities, and to plan for the initial management," write the authors of the 2014 Guidelines for the Primary Prevention of Stroke: A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association.

In addition, the American Academy of Neurology, in its summary of their 2014 Guideline on the Prevention of Stroke in Nonvalvular Atrial Fibrillation, states: "Clinicians should inform patients with NVAF [nonvalvular atrial fibrillation] that these patients have an increased stroke risk and that this risk can potentially be reduced by antithrombotic use. Patients should also be informed that antithrombotic use increases their risk of major bleeding."

During discussion after the presentation, Majersik commented that many ED physicians might resist the suggestion that they initiate and manage anticoagulation in high-risk people with AF because of workload constraints and the considerable time such care would require.

"I obviously want patients to have stroke prevention — but I'm wondering if the ER is the best place for that to be started," Majersik said. "And if it is, how is that supposed to happen in our current environment, and how do you ensure follow-up?"

"I am currently a medical student, so I'm not sure how fully I can answer," Hua said. "I think if we're able to start these patients on an anticoagulant [in the ED], they will be more adherent and take it more seriously, because they are being seen in the emergency department."

When asked by Medscape Medical News to comment, Majersik said the study "was well done, and I think it's worthwhile." She noted that the abstract was highly rated among neurologists who reviewed the stroke science presentations prior to the meeting.

"I think neurologists should consider this a population in their bucket, and partner with the ED physicians," she added.

"One way to do it is when you have a patient diagnosed with AF and they have a stroke, it's obviously too late," she said. "But better would be to have a prospective discussion and say, 'Maybe this is an opportunity for improvement.'"

Hua and Majersik have disclosed no relevant financial relationships.

American Academy of Neurology (AAN) 2019 Annual Meeting: Abstract S35.002. Presented May 8, 2019.

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