Abstract 18121: Extracranial Systemic Embolic Events in Patients With Atrial Fibrillation: Incidence and Outcomes
Background: Nonvalvular atrial fibrillation (AF) is associated with thromboembolic events, including stroke, but the impact of extracranial systemic embolic events (SEE) remains undefined. No prior study has accumulated a sufficient number of SEE to comprehensively evaluate their incidence, clinical characteristics and outcomes.
Methods: All suspected SEE reported among participants in recent large randomized trials were independently re-adjudicated by three clinicians for this analysis. Verification of SEE required clinical and objective evidence of sudden loss of perfusion of a limb or organ. The anatomic distribution, method of detection, severity and outcomes of events were abstracted from case report forms and source documents. The risk of SEE-related death was compared to stroke fatality by Cox proportional hazards regression analysis.
Results: Over 91,746 patient-years, 223 SEE occurred in 219 subjects, an incidence of 0.24/100 patient-years; the stroke rate during the same period was 1.92/100 patient-years. Patients with SEE were likely to be female (57%), mean age (SD) 73.4 (8.6) years, and mean CHADS2 score 2.4 (1.3), compared with 55.9%, 73.5 (8.9) years, CHADS2 score 2.5 (1.2) for patients with stroke. SEE most often involved lower extremity (61%), visceral-mesenteric arterial (28%), and upper extremity (11%) arterial beds. Severity ranged from clinic assessment alone (5%), to hospitalization (30%), surgical intervention (60%), and amputation (5%). Within 3 days of event, outcomes included full recovery in 55%, survival with deficit in 20%, and death in 24%. Mortality was greater after visceral-mesenteric than lower or upper extremity SEE (48, 16 and 9%, respectively, p=0.00001). The relative risk of death during long term follow-up of patients surviving until 3 days compared to those without event was 1.7 (95% CI 1.4, 2.1) after SEE and 1.8 (95% CI 1.7, 1.9) after stroke.
Conclusion: SEE constituted 11.5% of clinically manifest thromboembolic events in patients with AF. SEE are associated with considerable morbidity and mortality, depending upon the anatomical site. The risk of mortality associated with SEE is comparable to that of ischemic stroke. Improved surveillance for and earlier detection of SEE might improve outcomes.
- © 2013 by American Heart Association, Inc.