Mobile Aortic Atheroma and Systemic Emboli: Efficacy of Anticoagulation and Influence of Plaque Morphology on Recurrent Stroke

OBJECTIVES: We sought to determine the influence of plaque morphology and warfarin anticoagulation on the risk of recurrent emboli in patients with mobile aortic atheroma. BACKGROUND: An epidemiologic link between aortic atheroma and systemic emboli has been described both in pathologic and transesophageal studies. Likewise, a few studies have found an increased incidence of recurrent emboli in these patients. The therapeutic implications of these findings has not been studied. METHODS: Thirty-one patients presenting with a systemic embolic event and found to have mobile aortic atheroma were studied. The height, width and area of both immobile and mobile portions of atheroma were quantitated. The dimensions of the mobile component was used to define three groups: small, intermediate and large mobile atheroma. The patients were followed up by means of telephone interview and clinical records, with emphasis on anticoagulant use and recurrent embolic or vascular events. RESULTS: Patients not receiving warfarin had a higher incidence of vascular events (45% vs. 5%, p = 0.006). Stroke occurred in 27% of these patients and in none of those treated with warfarin. The annual incidence of stroke in patients not taking warfarin was 0.32. Myocardial infarction occurred in 18% of patients also in this group. Taken together, the risk of myocardial infarction or stroke was significantly increased in this group (p = 0.001). Forty-seven percent of patients with small, mobile atheroma did not receive warfarin. Recurrent stroke occurred in 38% of these patients, representing an annual incidence of 0.61. There were no strokes in patients with small, mobile atheroma treated with warfarin (p = 0.04). Likewise, none of the patients with intermediate or large mobile atheroma had a stroke during follow-up. Only three of these patients had not been taking warfarin. CONCLUSIONS: Patients presenting with systemic emboli and found to have mobile aortic atheroma on transesophageal echocardiography have a high incidence of recurrent vascular events. Warfarin is efficacious in preventing stroke in this population. The dimension of the mobile component of atheroma should not be used to determine the need for anticoagulation.