25677309
BACKGROUND	Brain lesions on diffusion-weighted imaging ( DWI ) are frequently found after carotid artery stenting ( CAS ) , but their clinical relevance remains unclear .
OBJECTIVE	This study sought to investigate whether periprocedural ischemic DWI lesions after CAS or carotid endarterectomy ( CEA ) are associated with an increased risk of recurrent cerebrovascular events .
METHODS	In the magnetic resonance imaging ( MRI ) substudy of ICSS ( International Carotid Stenting Study ) , 231 patients with symptomatic carotid stenosis were randomized to undergo CAS ( n = 124 ) or CEA ( n = 107 ) .
METHODS	MRIs were performed 1 to 7 days before and 1 to 3 days after treatment .
METHODS	The primary outcome event was stroke or transient ischemic attack in any territory occurring between the post-treatment MRI and the end of follow-up .
METHODS	Time to occurrence of the primary outcome event was compared between patients with ( DWI + ) and without ( DWI - ) new DWI lesions on the post-treatment scan in the CAS and CEA groups separately .
RESULTS	Median time of follow-up was 4.1 years ( interquartile range : 3.0 to 5.2 ) .
RESULTS	In the CAS group , recurrent stroke or transient ischemic attack occurred more often among DWI + patients ( 12 of 62 ) than among DWI - patients ( 6 of 62 ) , with a cumulative 5-year incidence of 22.8 % ( standard error [ SE ] : 7.1 % ) and 8.8 % ( SE : 3.8 % ) , respectively ( unadjusted hazard ratio : 2.85 ; 95 % confidence interval : 1.05 to 7.72 ; p = 0.04 ) .
RESULTS	In DWI + and DWI - patients , 8 and 2 events , respectively , occurred within 6 months after treatment .
RESULTS	In the CEA group , there was no difference in recurrent cerebrovascular events between DWI + and DWI - patients .
CONCLUSIONS	Ischemic brain lesions discovered on DWI after CAS seem to be a marker of increased risk for recurrent cerebrovascular events .
CONCLUSIONS	Patients with periprocedural DWI lesions might benefit from more aggressive and prolonged antiplatelet therapy after CAS .
CONCLUSIONS	( A Randomised Comparison of the Risks , Benefits and Cost Effectiveness of Primary Carotid Stenting With Carotid Endarterectomy : International Carotid Stenting Study ; ISRCTN25337470 ) .

