Does the use of a volatile anesthetic regimen attenuate the incidence of cardiac events after vascular surgery?

Objective : To compare the effects of a volatile anesthetic to a non-volatile anesthetic regimen on the incidence of postoperative cardiac events, including the postoperative elevation of troponin I values after arterial vascular surgery in high risk patients. Design : Retrospective analysis of data of a phase II study that compared the Na⁺/H⁺ exchanger type I inhibitor, zoniporide to placebo on the occurrence of cardiac events. Setting : Multicenter study conducted in 105 sites throughout the United States, South America, Europe and Asia Participants : 784 subjects scheduled for urgent or elective major arterial vascular surgery and a history of at least 3 of the following : age ≥ 65 years, hypertension, documented stroke or transient ischemic attack, previous myocardial infarction, active angina pectoris diabetes mellitus, congestive heart failure, or symptomatic cardiac arrhythmia. Interventions : Type of anesthesia was retrospectively retrieved from the database and patients were subdivided in two groups : inhalational (group A) vs non-inhalational anesthetic regimen (group B). Incidence of postoperative cardiac events was compared between the two groups. Measurements and Main Results : The incidence of postoperative cardiac events was not different between the two groups. Maximum postoperative troponin I levels was not different between the two groups in the total population and in the patients undergoing peripheral arterial surgery. In patients undergoing aortic surgery the incidence of elevated troponin levels higher than 1.5 and 4 ng.mL ^-1 tended to be lower in group A than in group B in the aortic surgery (28% vs 18% and 30% vs 20% respectively) but this difference did not reach statistical significance. Conclusion : The results of this hypothesis-generating study suggest that potential beneficial effects on extent of postoperative myocardial damage in high risk patients undergoing arterial surgery will probably be more apparent in abdominal aortic surgery than in peripheral vascular surgery. Further sufficiently powered studies using a standardized protocol should now be performed to definitively address this question.