Abstract TP203: New Onset Atrial Fibrillation Post Stroke

Abstract

Background: Atrial fibrillation (AF) makes a person five times more likely to experience a stroke. According to the National Stroke Association, atrial fibrillation accounts for about 15 percent of stroke. Many of these patients do not have any previous history of AF, and are diagnosed with this condition post-stroke. We sought to characterize the frequency and features of AF in stroke patients hospitalized after acute presentation, focusing on new diagnoses. Methods: All subjects were enrolled in the Field Administration of Stroke Therapy- Magnesium (FAST-MAG) clinical trial, a phase 3 NIH-funded study of pre-hospital Magnesium Sulfate vs. placebo for patients with symptom onset <2hours. General demographic information, past medical history, first electrocardiogram (ECG) in the emergency department (ED), and final diagnosis data were collected on consecutive subjects. Results: Of 1478 patients, 69 (4.7%) had no previous history of AF but were diagnosed with AF post-stroke onset. There were 274 cases with AF recorded on the ED ECG (274), only 36 (13.1%) had no documented history of AF. Patients in both groups were of similar age (age 81 vs 79 years) and had similar rates of ICH diagnosis (8.7 vs 7.1%). However, newly diagnosed patients had more severe strokes (median NIHSS 14 vs 10, p=0.008) and a lower burden of cardiac disease by history (coronary artery disease 15.9 vs 31.7%, and myocardial infarction 5.8 vs 15.9%). Female gender women (50.7 vs 48.2%) history of prior stroke (10.1 vs 8.8%), hypertension (89.9 vs 89.5%), and hyperlipidemia (56.5 vs 54.1%) were similar in both groups. Conclusion: Most new diagnoses of AF after stroke were made based on the ED ECG. Strokes in patients who would go on to have new AF diagnoses were more severe than those where AF diagnosis was already established, likely due to less likelihood of anticoagulation.