Vessel Wall Arachidonate Metabolism during Laser Coronary Angioplasty

Abstract

The mechanism of postangioplasty vasospasm is uncertain. It was postulated that alterations in arachidonic acid metabolism might contribute to spasm or acute occlusion of the treated coronary artery. In this study, coronary arterial plasma prostacyclin and thromboxane were monitored before and after argon laser ablations in canine coronary arteries (by standard radioimmunoassay of the metabolites 6-keto PGF_1α and TXB₂). Plasma 6-keto PGF_1α levels were unchanged or slightly increased (post/pre: 0.95 ∼ 1.82) in all cases after intracoronary laser ablations. However plasma TXB₂ levels were not increased (post/pre: 0.78 ∼ 1.44) in cases of uncomplicated laser ablations, but were remarkably increased (post/pre: 3.34 ∼ 6.64) in cases with laser complications, such as perforation or thermal vascular injury. These results suggest that uncomplicated laser ablations in the coronary arteries may not contribute to coronary spasm and acute coronary artery occlusion from the aspect of vessel wall arachidonate metabolism.