CAROTID ARTERY REVASCULARIZATION. Hemodynamic and cognitive implications

Abstract

Carotid endarterectomy (CEA) of the carotid artery prevents subsequent ischemic stroke. Sometimes carotid artery stenting (CAS) is an alternative. Physicians should be aware of short and long-term postprocedural complications of CAS and CEA. Section 1 concerns hemodynamic changes, their effect on the development of new cerebral ischemic lesions, and clinical outcome. Both treatments had a decrease in blood pressure (BP) at discharge. BP decreased more after CAS (mean difference (MD) between-groups in SBP 10.3 mmHg, 95%CI, 7.3 to 13.3). During follow-up BP-changes were not different between groups. However, fewer CAS-patients used antihypertensive medication during follow-up; CAS may lessen the need for antihypertensive medication more than CEA. The occurrence of periprocedural hemodynamic depression (severe bradycardia, asystole, or hypotension requiring treatment) and hypertension requiring treatment was assessed. Hemodynamic depression occurred in 13.8% CAS-patients and in 7.2% CEA-patients (relative risk (RR), 1.9; 95%CI 1.4 to 2.6). Hypertension requiring treatment occurred less after CAS (RR, 0.2; 95%CI, 0.1 to 0.4). The 30-day composite outcome of stroke, myocardial infarction (MI), or death occurred in 60 (7.8%) of CAS-patients and in 33 (4.0%) of CEA-patients. There was no significant association between hemodynamic complications and the composite outcome; thus the occurrence of hemodynamic depression after CAS does not explain its excess of major perioperative events. After CAS, patients with hemodynamic depression had 3-times more DWI lesions, compared with those without hemodynamic depression (RR, 3.36: 95%CI, 1.73 to 6.50). The number of lesions after CEA was too small. Section 2 describes cognitive consequences of carotid artery revascularization. The cognitive effects of CAS and CEA for symptomatic carotid artery stenosis were assessed. CAS had a larger decrease in cognition than CEA, but compared with CEA this was not statistically significant: -0.17 (95%CI, -0.38 to 0.03). DWI lesions were assessed in a subpopulation and occurred twice more after CAS than after CEA (RR, 2.1; 95%CI, 1.0 to 4.4). Cerebral white matter lesions (WML) are associated with cognitive impairment, and carotid revascularization with cognitive worsening or improvement. The relation between WML-severity and cognitive change after treatment was assessed. All patients declined in cognition: MD -0.21 (95%CI, -0.32 to -0.09). However, the sumscore-change was independent of WML-load: MD no-to-mild, -0.15 (95%CI, -0.39 to 0.09), moderate, -0.27 (95%CI, -0.48 to -0.06); and severe, -0.21 (95%CI, -0.40 to -0.04). In patients with a fetal-type posterior cerebral artery (FTP) (an embryonic variant that supplies the posterior cerebral artery (PCA) mainly by the internal carotid artery), ipsilateral stenosis is likely to result in a larger area with hypoperfusion than with a normal PCA. These patients could benefit more from revascularization. We compared the cognitive effects between patients with an FTP and those with a normal PCA. The cognitive sumscore decreased more in the 13 FTP-patients; by -0.28 (95%CI, 0.10 to 0.45) and by 0.07 (95%CI, 0.002 to 0.15) in 85 patients with a normal PCA (MD, -0.20; 95%CI, -0.40 to -0.01). The challenge for further studies assessing outcome after carotid revascularization is to identify the patients at risk of postprocedural major adverse events and cognitive decline.