Myocardial protection with volatile anaesthetic agents during coronary artery bypass surgery: a meta-analysis

Abstract

Previous studies have investigated the role of volatile anaesthetic agents in myocardial protection during coronary artery bypass graft (CABG) surgery, and some have identified beneficial effects. However, these studies have been too small to identify a significant effect on myocardial infarction (MI) or mortality. We undertook a systematic overview and meta-analysis of all randomized trials comparing volatile with non-volatile anaesthesia in CABG surgery. We identified 27 trials that included 2979 patients. There was no significant difference in myocardial ischaemia, MI, intensive care unit length of stay or hospital mortality between the groups (all P>0.05). Post-bypass, patients randomized to receive volatile anaesthetics had 20% higher cardiac indices (P=0.006), significantly lower troponin I serum concentrations (P=0.002) and lesser requirement for inotropic support (P=0.004) compared with those randomized to receive i.v. anaesthetics. Duration of mechanical ventilation was reduced by 2.7 h (P=0.04), and there was a 1 day decrease in hospital length of stay (P<0.001). Some of these outcomes were based on a smaller number of trials because of incomplete data, largely because the individual trials focused on one or more surrogate endpoints. We found some evidence that volatile anaesthetic agents provide myocardial protection in CABG surgery, but larger adequately powered trials with agreed, defined outcomes need to be done to fully assess a possible beneficial effect of volatile anaesthetic agents on the risk of MI and mortality.

One-year outcome of the sevoflurane in acute myocardial infarction randomized trial

“…9 When compared with intravenous anesthesia, sevoflurane has been shown to reduce the incidence of MI and intensive care unit stay, the length of time on mechanical ventilation following cardiac surgery, in-hospital mortality, and long-term cardiac events. [10][11][12][13][14] The effect of sevoflurane as a cardioprotective agent has not been shown in all studies, 15 and results were also dependent on duration of administration, number of exposures, and dose. For instance, in one study, the beneficial effects were observed only when administered throughout the surgery and not when administered in a fashion similar to ischemic conditioning, before cardiopulmonary bypass, or following the creation of the coronary anastomosis.…”

L’étude de la cardioprotection induite par le propofol: du mécanisme au phénomène clinique, et vice-versa

“…[3][4][5] In the current issue of the Journal, Ansley et al have pursued a different approach: They report the results of their clinical Phase 2 trial (PRO-TECT II) that assessed the impact of administering a targeted dose of systemic propofol during the ischemia-reperfusion interval in patients undergoing heart surgery. 6 They hypothesized that the antioxidant properties of propofol impart anesthetic preconditioning and protect ischemic myocardium from oxidative injury during cardiac surgery.…”

“…In juxtaposition to Ansley et al, several meta-analyses have demonstrated trends toward more favorable outcomes with inhalation anesthetics. [3][4][5] Yu and Beattie assessed a heterogeneous group of studies that demonstrated a trend toward decreased mortality with inhalation anesthetics. 3 Sevoflurane and desflurane, but not isoflurane, were associated with a decrease in postoperative troponin levels.…”

“…They also reported lower requirements for inotropic support with the use of these volatile anesthetics. 5 In both analyses, more than half of the studies utilized high-dose opioids and/or benzodiazepines, but not propofol, in the intravenous anesthetic arms, potentially weakening any direct comparison between the preconditioning effect of inhalation agent versus propofol. More recent metaanalyses that compared desflurane and sevoflurane with propofol-based anesthesia more directly arrived at a variety of conclusions.…”

“…En juxtaposition à l'étude de Ansley et coll., plusieurs méta-analyses ont démontré qu'il existait des tendances vers des pronostics plus favorables lorsqu'on avait recours à des anesthésiques par inhalation. [3][4][5] Yu et Beattie ont passé en revue un groupe hétérogène d'études qui démontraient une tendance vers une réduction de la mortalité avec les anesthésiques par inhalation. 3 Le sévoflurane et le desflurane, mais non l'isoflurane, ont été associés à une réduction des taux postopératoires de troponine.…”