Ischemic preconditioning does not improve myocardial preservation during off-pump multivessel coronary operation.
BACKGROUND
The value of ischemic preconditioning during coronary operations has remained controversial. The aim of this study was to evaluate the effects of ischemic preconditioning on myocardial energy metabolism and tissue injury during off-pump multivessel coronary surgery.


METHODS
Eleven patients with preceding preconditioning were compared with 11 patients without it. The preconditioning group underwent a 5-minute period of ischemia followed by a 5-minute reperfusion period before coronary occlusion for each of the first two anastomoses.


RESULTS
The transmyocardial differences (coronary sinus - arterial) in inosine and the sum of adenine degradation products increased in both groups, but the differences in xanthine and hypoxanthine increased only in the preconditioning group. Myocardial lactate production increased to a maximum of 0.09 mmol/L with preconditioning and to a maximum of 0.17 mmol/L without it. Transmyocardial pH differences increased to 0.03 U in both groups. The maximum postoperative concentration of creatine kinase-MB mass was 14.8 microg/L with preconditioning and 6.3 microg/L without preconditioning, and that of troponin I 7.4 microg/L and 5.2 microg/L, respectively. There were no statistically significant differences between the groups, however.


CONCLUSIONS
Ischemic preconditioning of 5 minutes followed by reperfusion of 5 minutes during off-pump multivessel coronary artery surgery did not prevent myocardial metabolic derangement and tissue injury and thus cannot be routinely recommended.
Penttilä
Hannu J
HJ
Department of Anesthesiology, Oulu University Hospital, Oulu, Finland. hannu.penttila@tyks.fi
Lepojärvi
Martti V K
MV
Kaukoranta
Päivi K
PK
Kiviluoma
Kai T
KT
Ylitalo
Kari V
KV
Peuhkurinen
Keijo J
KJ
D000241:Adenosine / Q000378:metabolism; D003331:Coronary Vessels / Q000601:surgery*; D003402:Creatine Kinase / Q000378:metabolism; D052279:Creatine Kinase, MB Form; D004734:Energy Metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007288:Inosine / Q000378:metabolism; D019194:Ischemic Preconditioning / Q000379:methods; D007527:Isoenzymes / Q000378:metabolism; D007773:Lactates / Q000378:metabolism; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D019210:Troponin I / Q000378:metabolism; D019820:Xanthine / Q000378:metabolism
D007527:Isoenzymes; D007773:Lactates; D019210:Troponin I; D019820:Xanthine; D007288:Inosine; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form; D000241:Adenosine