Silent stroke and cognitive decline in asymptomatic carotid stenosis revascularization

The aim of this study was to assess the relationship between serum levels of S100β and neuron-specific enolase (NSE), postoperative diffusion-weighted magnetic resonance imaging (DW-MRI) and Mini-Mental State Examination (MMSE) score in asymptomatic patients affected by ≥ 70% carotid stenosis submitted to carotid endarterectomy (CEA) or carotid artery stenting (CAS), and to compare MMSE scores and DW-MRI findings at follow-up evaluations. Between April 2008 and April 2009, 60 patients were submitted to carotid intervention. All patients underwent DW-MRI and MMSE preoperatively, at 24 hours postoperatively, at 6 months and at 12 months. Neurobiomarkers were assessed for each patient at six time-points. Thirty-two patients were submitted to CEA and 28 to CAS. No mortality was observed. One CAS patient presented with an ischemic stroke. In six CAS patients and one CEA patient, new subclinical ischemic lesions were detected at postoperative DW-MRI (21.4% versus 3%, P = 0.03). In CAS patients, new DW-MRI lesions were significantly associated with MMSE score decline (P = 0.001). At 12 months, patients presenting with new postoperative ischemic lesions showed lower MMSE scores (P = 0.08). CAS patients showed increasing neurobiomarker levels compared with CEA patients (P = 0.02). In conclusion, microembolization effects may persist over time, so it should be avoided whenever possible. Carotid revascularization procedures should be evaluated and compared not only with respect to death/stroke but also to microembolism rates.