Background: There are limited data on the baseline characteristics and clinical outcomes of patients who have recurrent hemispheric syndromes in the territory of symptomatic atherosclerotic internal carotid artery occlusion (AICAO).
Methods: Baseline characteristics and clinical outcomes were compared between patients with (rHEM+) and without (rHEM-) recurrent ipsilateral hemispheric syndromes at the time of randomization into the Carotid Occlusion Surgery Study (COSS) based on local investigator clinical impression.
Results: Of 195 participants who were randomized, 100 (51%) were rHEM+ (50 in each study arm) and 95 were rHEM-(48 nonsurgical, 47 surgical). Baseline characteristics between rHEM+ and rHEM- participants were similar except that rHEM+ participants were more likely to have had a previous stroke prior to entry event (59% vs 22%, p < 0.001) and to have had TIA vs stroke as the entry event (61% vs 20%, p<0.001). All primary endpoints were ipsilateral ischemic strokes. There were no statistically significant differences in the primary endpoint between nonsurgical and surgical participants with rHEM+ (26.3% vs 22.4%, p=0.660) or rHEM- (18.9% vs 19.5%%, p=0.943). For secondary endpoints based on stroke severity and/or death, no important differences were noted between nonsurgical and surgical participants for the rHEMI+ and rHEMI- subgroups (all p > 0.10). For the nonsurgical participants, there was no statistically significant difference in the primary endpoint for those rHEM+ vs rHEM- (26.3% vs 18.9%, p=.410)
Conclusion: Patients with recurrent hemispheric stroke syndromes enrolled in the COSS trial were more likely to have had previous stroke and to have TIAs as the entry event to randomization. Given the lack of surgical treatment benefit seen in these patients, early aggressive risk factor measures should be prioritized to reduce recurrent strokes, including blood pressure control which was associated with a 70% reduction in stroke in the nonsurgical group in COSS (Neurology 2014; 82:1027-1032).