Ischemic Stroke Risk in Atrial Flutter vs Fibrillation
Atrial flutter may be associated with a lower risk for stroke compared with atrial fibrillation.
The risk for ischemic stroke is lower in patients with atrial flutter than in those with atrial fibrillation, according to an analysis published in the Journal of Stroke & Cerebrovascular Diseases.
Patients aged 66 years and older with atrial fibrillation (n=318,138) and atrial flutter (n=14,953) were identified from inpatient and outpatient Medicare claims data from 2008 to 2014. For this analysis, the primary outcome was ischemic stroke during a mean follow-up period of 2.8 years.
During the follow-up period, a total of 18,900 ischemic strokes occurred in the sample.
Patients with atrial fibrillation had a 2.02% (95% CI, 1.99%-2.05%) annual incidence of ischemic stroke compared with a 1.38% annual ischemic stroke incidence (95% CI, 1.22%-1.57%) in patients with atrial flutter.
In addition, atrial flutter was associated with a lower risk for ischemic stroke than atrial fibrillation following adjustment for stroke and demographic risk factors (hazard ratio [HR], 0.69; 95% CI, 0.60-0.79; P <.05). More than half (65.7%; 95% CI, 64.9%-66.4%) of patients with atrial flutter developed atrial fibrillation; however, these patients continued to experience a lower ischemic stroke risk (HR, 0.85; 95% CI, 0.78-0.92).
The investigators of this analysis did not collect data on patients' anticoagulant use, which could have potentially affected stroke risk. Additionally, the findings from this study are possibly limited to the age group included in the final analysis (≥66 years) and may not be generalizable to other patient groups.
Findings from this analysis, “support current guidelines that recommend anticoagulation for patients with atrial flutter if it is accompanied by other stroke risk factors,” if no clear predictors of conversion from flutter to fibrillation are present.
Al-Kawaz M, Omran SS, Parikh NS, Elkind MSV, Soliman EZ, Kamel H. Comparative risks of ischemic stroke in atrial flutter versus atrial fibrillation [published online December 6, 2017]. J Stroke Cerebrovasc Dis. doi:10.1016/j.jstrokecerebrovasdis.2017.10.025