Altafullah, Irfan

Background: We have previously reported that carotid artery stenting (CAS) carries a higher stroke risk than carotid endarterectomy (CEA) in patients over the age of 70. The question arises if advanced age is a surrogate for other factors? If so, can those factors be separately identified such that advanced chronological age alone would not be considered a contra-indication for CAS? Here we consider whether the CAS/CEA choice could be guided by other factors known in the clinical center at the time of patient evaluation, independent of age, in order to provide optimal 4-year outcomes. Methods: Demographic factors (age, sex and race), symptomatic status, patient risk factors (hypertension, diabetes, dyslipidemia, smoking), and arterial characteristics (percent stenosis) were available on 2,502 patients. Additional detailed arterial characteristics (ulcerated plaque, distal tortuosity, sequential lesions, circumferential calcification) were available on 1141 CAS and 438 CEA patients. Potential differential treatment efficacy was assessed by the addition of factor-by-treatment interaction terms to a proportional hazard model containing established predictors of outcome (treatment, symptomatic status, sex, age and age-by-treatment interaction). Results: No other factor was found to mitigate advanced age with evidence of additional treatment effect modification of 4-year outcome (p > 0.10). Discussion: Beyond the previously described differential treatment efficacy by age, there were no other patient or arterial characteristic detected to identify patient subgroups that would differentially benefit from the choice of CAS versus CEA. Our inability to identify factors to guide treatment choices could be due to the low number of stroke and death events, incomplete information regarding arterial characteristics in the CEA population, or the potential exclusion of “high risk” groups (such as those with severe arterial tortuosity) from the study.

Background and Purpose— Prior meta-analysis showed that carotid endarterectomy benefits decline with increasing surgical delay following symptoms. For symptomatic patients in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), we assessed if differences in time between symptoms and carotid endarterectomy or carotid artery stenting are associated with differences in risk of periprocedural stroke or death. Methods— We analyzed the 1180 symptomatic patients in CREST who received their assigned procedure and had clearly defined timing of symptoms. Patients were classified into 3 groups based on time from symptoms to procedure: <15, 15 to 60, and >60 days. Results— For carotid endarterectomy, risk of periprocedural stroke or death was not significantly different for the 2 later time periods relative to the earliest time period (hazard ratio, 0.74; 95% confidence interval, 0.22–2.49 for 15–60 days and hazard ratio, 0.91; 95% confidence interval, 0.25–3.33 for >60 days; P =0.89). For carotid artery stenting, risk of periprocedural stroke or death was also not significantly different for later time periods relative to the earliest time period (hazard ratio, 1.12; 95% confidence interval, 0.53–2.40 for 15–60 days and hazard ratio, 1.15; 95% confidence interval, 0.48–2.75 for >60 days; P =0.93). Conclusions— Time from symptoms to carotid endarterectomy or carotid artery stenting did not alter periprocedural safety, supporting early revascularization regardless of modality. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00004732.