Myocardial preservation during coronary surgery with and without cardiopulmonary bypass.
BACKGROUND
There is increased interest in coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB), although the preservation of the myocardium under such circumstances has not been properly investigated. The aim of this randomized study was to compare the changes in myocardial metabolism during CABG with and without CPB.


METHODS
Myocardial energy metabolism and tissue injury during CABG was monitored in a series of 22 patients (11 with and 11 without CPB).


RESULTS
The maximum myocardial lactate production was significantly higher (p = 0.02) in the group operated with CPB (0.56 mmol/L) than without it (0.17 mmol/L). A similar phenomenon was seen in the transcardiac pH differences (0.085 and 0.034 with and without CPB, p = 0.007). The postoperative peak values of creatine kinase-MB mass (15.1 vs 6.3 microg/L) and troponin I (13.8 vs 5.2 microg/L) were significantly higher (p < 0.001 and p = 0.008) with than without CPB.


CONCLUSIONS
CABG on a beating heart is associated with better myocardial energy preservation and less myocardial damage compared with conventional CABG with CPB and intermittent antegrade mild hypothermic blood cardioplegia.
Penttilä
H J
HJ
Department of Anesthesiology, Oulu University Hospital, Finland. hannu.penttila@oulu.fi
Lepojärvi
M V
MV
Kiviluoma
K T
KT
Kaukoranta
P K
PK
Hassinen
I E
IE
Peuhkurinen
K J
KJ
D000368:Aged; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000503:physiopathology / Q000601:surgery*; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007431:Intraoperative Complications / Q000503:physiopathology*; D007527:Isoenzymes / Q000097:blood; D019344:Lactic Acid / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D019210:Troponin I / Q000097:blood
D007527:Isoenzymes; D019210:Troponin I; D019344:Lactic Acid; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form