Meta-Analysis Finds No Comparative Benefit of Proximal Occlusion Versus Distal Filter for Cerebral Protection in CAS

June 30, 2015—An updated meta-analysis of randomized and observational magnetic resonance imaging (MRI) studies comparing proximal occlusion (PO) versus distal filter (DF) for cerebral protection during carotid artery stenting (CAS) was published by Salvatore Cassese, MD, et al in EuroIntervention (2015;11:238–246).

The background of that study is that new cerebral lesions at diffusion-weighted magnetic resonance imaging (DW-MRI) represent a surrogate endpoint for embolization, although their clinical impact is controversial. Therefore, the investigator performed a meta-analysis of randomized and observational DW-MRI studies comparing PO and DF during CAS.

As summarized in EuroIntervention, the investigators searched electronic scientific databases, analyzing a total of 392 patients in seven studies who received CAS. The primary endpoint was the incidence of new cerebral lesions at DW-MRI. Secondary endpoints were the incidence of new ipsilateral and new contralateral cerebral lesions at DW-MRI and death/cerebrovascular events.

The investigators reported that at DW-MRI after 48 hours, 178 patients (48.3%) presented new cerebral lesions. The use of PO versus DF reduced neither the risk of new cerebral lesions nor the risk of death/cerebrovascular events. Diabetes and baseline stenosis and symptoms significantly modified the risk estimates for new cerebral lesions.

In this meta-analysis, one half of patients receiving protected CAS developed new embolic cerebral lesions at DW-MRI, although the overwhelming majority of patients were asymptomatic. Cerebral protection with PO versus DF neither reduced cerebral embolization nor had an impact on clinical outcomes, concluded the investigators in EuroIntervention.