HEPARIN-BONDED CIRCUITS DECREASE MYOCARDIAL ISCHEMIC DAMAGE - AN EXPERIMENTAL-STUDY

Background. Heparin-bonded cardiopulmonary bypass circuits reduce comp lement activation, but their effect on myocardial function is unknown. This study was undertaken to determine whether heparin-bonded circuit s reduce myocardial damage during acute surgical revascularization. Me thods. In 16 pigs, the second and third diagonal vessels were occluded with snares for 90 minutes followed by 45 minutes of cardioplegic arr est and 180 minutes of reperfusion with the snares released. During th e period of coronary occlusion, all animals were placed on percutaneou s bypass followed by standard cardiopulmonary bypass during the period s of cardioplegic arrest and reperfusion. In 8 pigs, heparin-bonded ci rcuits were used, whereas 8 other pigs received nonbonded circuits. Re sults. Animals treated with heparin-bonded circuits had the best prese rvation of wall motion scores (3.5 +/- 0.3 versus 2.3 +/- 0.2; 4 = nor mal to -1 = dyskinesis; p < 0.05), least tissue acidosis (change in pH = -0.31 +/- 0.02 versus -0.64 +/- 0.08; p < 0.05), smallest increase in lung H2O (1.7% +/- 1.7% versus 6.1% +/- .5%; p < 0.05), and the low est area of necrosis/area of risk (20.3% +/- 2.2% versus 40.4% +/- 1.6 %; p < 0.05). Conclusions. We conclude that heparin-bonded circuits si gnificantly decrease myocardial ischemic damage during acute surgical revascularization. (C) 1997 by The Society of Thoracic Surgeons.