Sevoflurane improves myocardial ischaemic tolerance in a closed-chest porcine model.

AIMS: Volatile anaesthetics prevent experimental myocardial ischaemia-reperfusion injury (I/R) in several species, but this finding is partially inconsistent with clinical evidence. Some experimental models may not accurately represent the complex signal transduction pathways triggered by volatile anaesthetics. We therefore investigated sevoflurane I/R prevention in vivo in a porcine model with greater likeness to human physiology than models previously used and compared it with neutral anaesthetic. METHODS AND
RESULTS: Myocardial infarct size [IS/AAR] was compared in three groups of pigs (N=35) randomised to Control anaesthesia (pentobarbital infusion, n=12), sevoflurane inhalation alone (end-tidal concentration 3.2%) (Sevo, n=9), or both Combined (n=14), throughout ischaemia and reperfusion. Anterior/septal myocardial infarcts resulted from distal LAD coronary artery occlusion by balloon catheter for 45 min followed by 120 min of reperfusion. [IS/AAR] was measured in tetrazolium-stained heart slices after standardised image processing with computer-assisted planimetry. Measurements included full invasive monitoring. Control animals developed infarction in 55.0 +/- 3.9% (SEM) of the area at risk, Sevo in 17.5 +/- 4.4% (P=0.0002), and Combined with pentobarbital in 24.3 +/- 3.8% (P=0.0001) of the AAR, sevoflurane reducing infarct size significantly (68% and 60%, respectively).
CONCLUSIONS: Sevoflurane markedly decreased myocardial infarct size after prolonged coronary occlusion in a porcine model. In addition to novel sevoflurane cardioprotection in the closed-chest model, which is more comparable to normal human hearts than models previously used, sevoflurane cardioprotection is substantiated in the juvenile intact organism. The perspectives underline recommending volatile anaesthetics in risk patients and in cardiac surgery.