Anesthetic type and risk of myocardial infarction after carotid endarterectomy in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST)

Abstract

Carotid endarterectomy (CEA) is usually performed under general anesthesia (GA), although some advocate regional anesthesia (RA) to reduce hemodynamic instability and allow neurologic monitoring and selective shunting. RA does not reduce risk of periprocedural stroke or death, although some series show a reduction in myocardial infarction (MI). We investigated the association of anesthesia type and periprocedural MI among patients receiving GA or RA for CEA and patients undergoing carotid artery stenting (CAS) in the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST). Between 2000 and 2008, 1151 patients underwent CEA (anesthetic type available for 1149 patients), and 1123 patients underwent CAS ≤30days of randomization in CREST. CEA patients were categorized by anesthetic type (GA vs RA). CREST defined protocol MI as chest pain or electrocardiogram change plus biomarker evidence of MI, and total MI was defined as protocol MI plus biomarker-positive (+)-only MI. The incidence of protocol MI and total MI in patients undergoing CEA under GA and RA were compared with those undergoing CAS. Other study end points were similarly compared. Differences in baseline characteristics and periprocedural events were evaluated among the three groups. Logistic regression, adjusting for age and symptomatic status, was used to assess group differences. The three groups had similar demographic risk factors, except for prevalence of symptomatic carotid stenosis, which was lowest in the CEA-RA group (P= .03). Of the 111 patients in the CEA-RA group, no protocol MIs occurred and only two biomarker+-only MIs, for an overall incidence of 1.8%, similar to the 1.7% overall incidence in patients undergoing CAS. In contrast, the combined incidence of protocol and biomarker+-only MIs in the 1038 patients in the CEA-GA group was significantly higher at 3.4% (P= .04), twice the risk of protocol MI and biomarker+-only MI compared with those undergoing CAS (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.14-3.54). Direct comparison of the MI incidence between CEA-RA and CEA-GA showed no statistical difference. Patients undergoing CEA-GA had lower odds of a periprocedural stroke (OR, 0.48; 95% CI, 0.28-0.79) and stroke or death (OR, 0.46; 95% CI, 0.27-0.76) compared with those undergoing CAS but were not significantly different from those undergoing CEA-RA. Patients in CREST undergoing CEA-RA had a similar risk of periprocedural MI as those undergoing CAS, whereas the risk for CEA-GA was twice that compared with patients undergoing CAS. Nevertheless, because periprocedural MI is one of the few variables favoring CAS over CEA and has been associated with decreased long-term survival, RA should be seriously considered for patients undergoing CEA.