Embolism from the Aorta: Atheroemboli and Thromboemboli

To date, there are no evidence-based data to support specific drug therapy for a patient with atheroembolism. It makes sense to use HMG CoA (3-hydroxy-3-methylglutaryl coenzyme A) reductase inhibitors (statins) in any patient with atherosclerosis, as these drugs have been shown to reduce the risk of myocardial infarction and stroke, and have a theoretical benefit on plaque stabilization. Surgical treatment should be considered for patients with abdominal aortic or popliteal artery aneurysms and downstream atheroembolism. There are case reports of atheroemboli in patients worsening after given warfarin or heparin. For this reason, some institutions are reluctant to prescribe these drugs for patients with atheroemboli or thromboemboli from aortic plaque. However, the incidence of this complication is quite low. Anticoagulation probably should be stopped if a patient develops atheroembolism. Similarly, the current state of knowledge does not allow for selecting specific pharmacologic intervention in patients with thromboemboli from aortic plaque. Statin therapy does make sense, as these drugs theoretically stabilize plaques and prevent plaque hemorrhage, thrombosis, and subsequent embolization. Unstable aortic plaques may develop superimposed thrombi (red thrombi on pathologic examination), easily seen as mobile elements on transesophageal echocardiography. Therefore, it is possible that anticoagulation with warfarin might prevent embolic events in these patients. For this reason, we are often in the position of recommending warfarin therapy for patients with emboli and severe atheromas seen on transesophageal echocardiography, especially when superimposed mobile thrombi are seen. There are small series in the literature that indicate the potential benefit of warfarin. However, until a large multicenter randomized clinical trial is done, the use of warfarin can not be definitively recommended. Antiplatelet agents, although safer than warfarin (less risk of hemorrhage), have not been proven beneficial in patients with thromboembolism from the aorta. Surgery (endarterectomy) of the aortic arch is a very risky procedure that should not be performed routinely, but may be used in highly selected patients.