Locoregional versus general anesthesia in carotid surgery: Is there an impact on perioperative myocardial ischemia? Results of a prospective monocentric randomized trial

Purpose: The incidence of cardiac morbidity and mortality in patients who u ndergo carotid surgery ranges from 0.7% to 7.1%, but it still represents al most 50% of all perioperative com plications. Because no data are available in literature about the impact of the anesthetic technique on such complic ations, a prospective randomized monocentric study was undertaken to evalua te the role of local anesthesia (LA) and general anesthesia (GA) on cardiac outcome. Methods: From November 1995 to February 1998, 107 patients were classified by the cardiologist as cardiac patients (IHD; history of myocardial infarct ion, previous myocardial revascularization procedures, or myocardial ischem ia documented by means of positive electrocardiogram [ECG] stress test resu lts) or noncardiac patients (NIHD; no history of chest pain or negative res ults for an ECG stress test). The patients were operated on after the rando mization for the type of anesthesia (general or local). Continuous computer ized 12-lead ECG was performed during the operative procedure and 24 hours postoperatively. The end points of the study were ECG modifications (upslop ing or downsloping more than 2 mm) of the sinus tachycardia (ST) segment. Results: Fifty-five patients were classified as IHD, and 52 were classified as NIHD. Twenty-seven of the 55 IHD patients (49%) and 24 of 52 NIHD patie nts (46%) were operated on under GA. Thirty-six episodes of myocardial isch emia occurred in 22 patients (20.5%). Episodes were slightly more frequent (58%) and longer in the postoperative period (intraoperative, 10 +/- 5 min; postoperative, 60 +/- 45 min; P <.001). As expected, the prevalence of myo cardial ischemia was higher in the group of cardiac patients than in noncar diac group (15 of 55 patients [27%] vs 7 of 52 patients [13%]; P <.02). By comparing the two anesthetic techniques in the overall population, we found a similar prevalence of patients who had myocardial ischemia (GA, 12 of 52 [23%]; LA, 10 of 55 [18%]; P = not significant) and a similar number of is chemic episodes per patient (GA, 1.5 +/- 0.4; LA, 1.8 +/- 0.6; P = not sign ificant). Episodes of myocardial ischemia were similarly distributed in int raoperative and postoperative periods in both groups. It is relevant that u nder GA, IHD patients represent most of the population who suffered myocard ial ischemia (83%). On the contrary, in the group of patients operated on u nder LA, the prevalence was equally distributed in the two subpopulations. Conclusion: The results confirm the different hemodynamic impact of the two anesthetic techniques. Patients who received LA had a rate of myocardial i schemia that was half that of patients who had GA. The small number of card iac complications do not permit us to make any definitive conclusion on the impact of the two anesthetic techniques on early cardiac morbidity, but th e relationship between perioperative ischemic burden and major cardiac even ts suggests that LA can be used safely, even in high-risk patients undergoi ng carotid endarterectomy.