Safety and effectiveness of anticoagulation in the management of acute stroke and transient ischemic attack due to intracranial and extracranial non-occlusive thrombus

Abstract

Introduction: The awareness of nonocclusive thrombus has increased with the increasing frequency of imaging methods used for acute ischemic stroke; however, the best treatment for nonocclusive thrombi is still unknown. In this study, we examined how anticoagulants affect supra-aortic artery nonocclusive thrombus and clinical outcomes.

Materials and methods: This study included 52 patients with transient ischemic attack or stroke who were diagnosed with nonocclusive thrombi on computed tomography angiography at admission. Patients were treated with anticoagulant treatment and grouped according to treatment modality (either unfractionated heparin or low molecular weight heparin) and treatment duration. Primary safety outcome was major bleeding defined as immediate and clnically significant hemorrhage. Anticoagulant treatment was continued until the thrombus was resolved as determined by consecutive weekly computed tomography angiography controls. After thrombus resolution, treatment was directed according to the underlying etiology. Antiaggregation treatment was the preferred treatment after thrombus resolution for patients with no observed etiology.

Results: The affected internal carotid arteries were most frequently located in the cervical segment (48 %). Complete resolution was achieved within 2 weeks in 50 patients (96 %). The involved vasculature included the following: the extracranial carotid artery segments (n = 26, 50 %), intracranial ICA segments (n = 10, 19 %), basilar artery segments (n = 8, 15 %) and MCA segments (n = 7, 13 %). The most common underlying pathologies were atherosclerosis (n = 17), atrial fibrillation (n = 17), undetermined embolic stroke (n = 8), dissection (n = 7), and malignancy (n = 2). No symptomatic intra- or extracranial bleeding complications due to anticoagulant use were observed in any patient during the study period. A good functional outcome (modified Rankin scale score 0-2) was achieved in 49 patients (94 %) at 3 months. There was no significant difference between treatment type and duration in terms of reinfarction (p = 0.97 and p = 0.78, respectively).

Conclusion: Anticoagulant treatment is safe and effective in symptomatic patients with intracranial or extracranial artery nonocclusive thrombus, regardless of the anticoagulant type, thrombus location and size.

Keywords: Anticoagulant treatment; Free-floating thrombus; Non-occlusive thrombus; Stroke.