Effects of Age and Symptom Status on Silent Ischemic Lesions after Carotid Stenting with and without the Use of Distal Filter Devices

The routine use of distal filter devices during carotid angioplasty and stent placement (CAS) is controversial. The aim of this study was to analyze their effects on the incidence of new diffusion-weighted imaging (DWI) lesions as surrogate markers for stroke in important subgroups. DWI was performed immediately before and after CAS in 68 patients with and 175 without protection, and patients were further subdivided according to their age or symptom status. The proportion of patients with new ipsilateral DWI lesion(s) was significantly lower after protected versus unprotected CAS (52% versus 68%), as well as in symptomatic patients (56% versus 74%) or those at or younger than 75 years of age (46% versus 67%; all P < .05). Similarly, the total number of lesions was significantly lower after protected versus unprotected CAS (median, 1; interquartile range [IQR], 0-2; versus median, 1; IQR 0-4.75) and in symptomatic patients (median, 1; IQR, 0-3; versus median, 2; IQR, 0-6) or those at or younger than 75 years of age (median, 0; IQR, 0-2; versus median, 1; IQR, 0-4; all P < .05). In contrast, for asymptomatic patients (48% versus 52%; P = .8; median, 0; IQR, 0-2; versus median, 1; IQR, 0-2.5; P = .6) or those older than 75 years of age (73% versus 69%; P = .7; median, 1; IQR, 0-4; versus median, 1.5; IQR, 0-5.75; P = .6), the proportion of patients with new lesion(s) and the total number of these lesions were not significantly different between protected and unprotected CAS. The use of distal filter devices generally reduces the incidence of new DWI lesions; however, this beneficial effect might not necessarily pertain to older and asymptomatic patients.