Abstract TMP76: Inadequate Pre-Procedure Antiplatelet Medication Use May Explain the Higher Risk of Peri-Procedural Stroke and/or Death with Carotid Stent Placement within First 7 Days after Qualifying Ischemic Event

Background and Purpose: In randomized trials, carotid artery stent (CAS) may have higher risk of periprocedural risk compared with carotid endarterectomy (CEA) if performed within the first 7 days after the onset of symptoms.

Methods: We analyzed the data from Carotid Revascularization Endarterectomy versus Stenting Trial (CREST). The time interval between the most recent qualifying ischemic event and CAS/CEA procedure was divided in four strata: 1-7 days, 8-14 days, 15-30 days and >30 days. We analyzed the effect of time interval strata between most recent qualifying ischemic event and procedure and procedure type (CEA versus CAS) on peri-procedural stroke and/or death after adjusting for age, gender, symptomatic status and initial severity of stenosis (≥70% versus <70%).

Results: The rate of periprocedural stroke and/or death was significantly higher in patients who underwent CAS compared with CEA at 7 days or less after the qualifying event (5.4% versus 0%, p=0.031) but not significantly different in patients who underwent CAS compared with CEA at 8-14 days (3.8%versus 2.0%, p=0.68), at 15-30 days (5.1% versus 1.8%, p=0.26) days and >30 days (CAS 7.8% versus CAE 4.3%, p=0.12), after the most recent qualifying event. In the multivariate analysis, patients who underwent CAS had higher rate of peri-procedural stroke and/or death (odds ratio [OR] 2.36, 95% confidence interval [CI] 1.25- 4.66) but timing of procedure were not associated with higher rate of peri-procedural stroke and/or death after adjustment for potential confounders. The interaction between procedure type and timing of procedure was not significant. The rate of peri-procedural stroke and/or death was significantly higher in CAS patients who received clopidogrel bolus (without 48-hour maintenance dose) among patients treated 7 days or less after the qualifying event compared with those undergoing CEA (6.6% versus 0%, p=0.012) but was not different between CAS patients who received 48 hours of clopidogrel maintenance and those undergoing CEA (0% versus 0%).

Conclusions: The higher rate of peri-procedural stroke and/or death seen with CAS (compared with CEA) within the first 7 days may be attributed to factors such as inadequate pre-procedure antiplatelet medication use. The results of CAS and CEA may become comparable within the first 7 days after the qualifying ischemic event with use of newer generation P2Y12 platelet inhibitors that achieve rapid antiplatelet inhibition.