Does Cognitive Dysfunction after Carotid Endarterectomy Vary by Statin Type or Dose?

Abstract

Our previous work demonstrates that asymptomatic carotid endarterectomy (CEA) patients demonstrate less perioperative neurologic injury, defined as stroke and early cognitive dysfunction (eCD) observed within 24hr of CEA, when taking statins pre-operatively. This study examines whether the incidence of eCD observed 24hr after asymptomatic CEA varies as a function of statin type or dose. Patients with asymptomatic carotid stenosis scheduled for CEA consented to participate in an observational IRB-approved study (N=324). Patients were evaluated with an extensive battery of neuropsychometric tests pre-operatively and 24hr post-operatively. Of the 324 consented patients, 200 were taking statins. Patients taking pravastatin and fluvastatin exhibited no eCD, while patients taking lovastatin (17.7%) and rosuvastatin (16.7%) exhibited incidences of eCD similar to those not taking statins (20.2%). Patients taking simvastatin exhibited a significantly lower incidence of eCD than those taking atorvastatin (3.0% vs. 16.0%, P=0.005). Patients taking a maximal dose of any statin exhibited a significantly lower incidence of eCD than patients taking sub-maximal doses (2.7% vs. 15.9%, P=0.002). These observations suggest that the incidence of eCD may in fact vary as a function of statin type and that maximal doses may be the optimal dose for patients undergoing CEA. This variation may be due to the physico-chemical properties of statins such as lipophilicity, molecular size, and blood brain barrier penetrability. These findings should be used to inspire randomized prospective work to determine the safety, feasibility, and outcomes of optimizing statin use prior to CEA.