Recurrent Hemispheric Stroke Syndromes in Symptomatic Atherosclerotic Internal Carotid Artery Occlusions: The Carotid Occlusion Surgery Study Randomized Trial.

Abstract

There are limited data on outcomes of extracranial-intracranial (EC-IC) bypass in patients with recurrent hemispheric syndromes due to atherosclerotic internal carotid artery occlusion (AICAO). To compare clinical outcomes and efficacy of EC-IC bypass surgery in patients with and without recurrent hemispheric syndromes associated with AICAO in the Carotid Occlusion Surgery Study (COSS). In patients enrolled in the COSS trial, we compared baseline characteristics and clinical outcomes for participants with (rHEMI+) and without recurrent hemispheric ischemia (rHEMI-) prior to randomization into surgical vs medical groups. The primary outcome was all stroke and death from randomization through 30 d and ipsilateral ischemic stroke within 2 yr. Of 195 randomized participants, 100 were rHEMI+ (50 in each group). Baseline characteristics between rHEMI+ and rHEMI- participants were similar except rHEMI+ were more likely to have had previous stroke prior to randomization (61% vs 20%, P<.01) and to have TIA as the entry event (59% vs 21%, P<.01). All primary endpoints were ipsilateral ischemic strokes. There were no significant differences in occurrence of the primary endpoint between nonsurgical and surgical participants in rHEMI+ (26.3% vs 22.4%, P=.660) and rHEMI- (18.9% vs 19.5%, P=.943). For nonsurgical participants, there was no significant difference in the primary endpoint for rHEMI+ vs rHEMI- patients (P=.410). Patients with recurrent hemispheric stroke syndromes enrolled in the COSS trial did not show benefit from EC-IC bypass compared to medical treatment. Early aggressive risk factor measures should be prioritized to reduce recurrent strokes in these patients.