Suppression of Graft Spasm by the Particulate Guanylyl Cyclase Activator in Coronary Bypass Surgery

Background: Spasm of arterial grafts is still a clinical problem in coronary artery bypass surgery. The present study was designed to examine the effect of particulate guanylyl cyclase activator (carperitide) as an antispastic agent in internal thoracic artery and gastroepiploic artery grafts.

Methods: Isolated arterial grafts taken during surgery were studied in organ bath in three ways: the relaxing effect of carperitide on vasoconstrictor-induced precontraction; the inhibitory effect of pretreatment with carperitide on subsequent vasoconstrictor-induced contraction; and the effect of carperitide and nitroglycerin on increase of intracellular cyclic guanosine monophosphate levels.

Results: Carperitide produced a concentration-related, endothelium-independent relaxation contracted with potassium chloride, phenylephrine, prostaglandin F_2α, or endothelin-1. Carperitide showed significantly higher potency and efficacy than nitroglycerin and nifedipine. Pretreatment with carperitide significantly attenuated the subsequent vasoconstrictor-induced contraction. Carperitide produced more cyclic guanosine monophosphate than nitroglycerin.

Conclusions: Carperitide has a potent inhibitory effect on the vasoconstriction mediated by different vasoconstrictors in human internal thoracic artery and gastroepiploic artery grafts. The use of carperitide in patients during and after coronary artery bypass surgery is favored for the prevention and reversal of graft spasm.