Important Predictors of DWI Lesions and Neurological Sequelae Following Carotid Intervention

Abstract

Embolic detection on diffusion weighted imaging (DWI) by magnetic resonance imaging (MRI) is a promising outcome measure for carotid interventions. We previously reported that patients undergoing carotid artery stenting (CAS) have a 50% greater chance of developing new microemboli on DWI compared to carotid endarterectomy (CEA). We sought to re-evaluate these outcomes in a larger patient set after technical modifications to our CAS program. We also examined the risk factors for DWI lesions and correlated neurologic symptoms with DWI-derived MLV. From July 2004 to December 2010, a total of 228 patients (143 CEA, 85 CAS) who underwent carotid interventions also received preoperative and postoperative DWI evaluations at a single academic institution. A novel neuroimaging analysis technique was used to derive MLV on DWI. Hospital records for all patients were reviewed for comorbidities, lesion characteristics, postoperative outcomes, and incidence of periprocedural microemboli. Forty patients (47%) with CAS compared to 15 patients (10%) with CEA had postoperative DWI lesions (P < .01), and a higher incidence of contralateral microembolization (P = .01). Multivariant analysis demonstrated that the strongest predictors of DWI lesions after CAS or CEA were body mass index (BMI) > 30 (P < .01; confidence interval [CI], 1.4-8), preoperative stroke (P < .01; CI, 2.9-15.3), chronic obstructive pulmonary disease (COPD; P = .03; CI, 1.1-6.2), and coronary artery disease (CAD; P = .05; CI, 1-6.2; Table). Subset analysis of MLV demonstrated a significant correlation with the incidence of postoperative neurological symptoms (P = .04; R2 0.248). MLV was not different between CAS and CEA (P = .13).TableMultivariant analysis of perioperative factorsFactorP valueCIAge >70.705.2-2.6Gender.090.02-1.3Smoking.680.4-1.9Hypertension.530.1-3.4Hyperlipidemia.890.2-5.3Obesity (BMI >30)< .011.4-8CAD.051-6.2COPD.031.1-6.2PVD.160.2-1.3Preoperative stroke< .012.9-15.3Carotid lesion calcificationBMI, Body mass index; CAD, coronary artery disease; CI, confidence interval; COPD, chronic obstructive pulmonary disease; PVD, peripheral vascular disease. Open table in a new tab BMI, Body mass index; CAD, coronary artery disease; CI, confidence interval; COPD, chronic obstructive pulmonary disease; PVD, peripheral vascular disease. The incidence of microembolic events after CAS is higher compared to CEA, but the MLV is similar for the two groups. DWI-derived MLV highly correlates with postprocedural neurological sequelas. Further investigational use of periprocedural DWI is needed to determine the utility and cost-effectiveness of identifying patients at risk of neurological sequelas after carotid intervention.