DISCUSSION
TIA, carotid disease, stroke, strokes, infarcts, cognitive decline, long-term recurrent stroke, TIAs
CAROTID DISEASE, STROKE, EVENT, EVENTS, TIA, STROKES
The current study demonstrated that new periprocedural DWI lesions were not associated with a higher risk of recurrent stroke or TIA at long-term follow-up in symptomatic patients after carotid revascularization with CEA or CAS.In the ICSS MRI substudy, both the presence and count of DWI lesions were associated with recurrent stroke/TIA occurring after the posttreatment scan with most events seen in the first 6 months after treatment.Currently, DWI lesions are already being used as periprocedural outcome marker in, for example, carotid stenting studies. A randomized controlled trial comparing conventional single-layer versus MicroNet-covered stents showed that the latter significantly reduced the amount and volume of periprocedural ipsilateral DWI lesions, and a 3:1 difference was seen in the number of permanent lesions on FLAIR after 30 days.This study failed to demonstrate the relevance of DWI lesions after CEA and CAS separately, due to the small sample sizes and number of events. Outcome events were mainly caused by DWI+ patients in the stenting group, which may be explained by the higher age in this group. A meta-analysis in 2017 showed a stable ratio when comparing new DWI lesions to the number of strokes and TIAs among patients undergoing different carotid artery intervention (CEA and CAS).Increasing attention has arisen toward the concomitant risks of the management of the carotid disease on cognition. Irreversible (silent) brain infarcts are already proposed as predictor for cognitive decline.Important to note is that definition remains key in studying the relevance of new periprocedural DWI lesions.The strengths of our study relate to the use of data from a multicenter randomized controlled trial. This study also has some limitations. First, both 1.5- and 3-T MRI scanners were used, which may have caused a difference in sensitivity in the detection of DWI lesions. Second, its retrospective nature and small sample size since only patients from UMCU and Erasmus MC were included. Moreover, some GPs did not respond or could not be retrieved. Third, in the first 5 years, the follow-up data were retrieved annually with event adjudication by an independent outcome committee. In the current study, the successive years were requested through the general practitioner with the risk that events may have been missed or misattributed. Also, the previously published ICSS MRI substudyIn conclusion, the results from our analysis do not support the role of ischemic brain lesions discovered on DWI after carotid revascularization procedures as risk markers for long-term recurrent stroke or TIA. However, as new periprocedural DWI lesions seem to be a marker for early recurrent cerebrovascular events, future randomized studies are needed to evaluate whether the effect of treatment on these lesions corresponds to the effect of treatment on procedural stroke before surrogacy can be validated.