995-16 Endothelial Dysfunction of Spasm-related Coronary Artery in Patients with Variant Angina

To investigate endothelial function in pts with variant angina(VA) with angiographically near normal coronary arteries, quantitative coronary angiographic study was done with continuous intracoronary infusion of incremental dose (from 10-9 to 10-6M) of acetylcholine (Ach) and ergonovine (Erg). Changes in luminal diameter in spastic and nonspastic segments of spasm related artery of pts with VA (n=28, mean age=53) was compared to those of normal control pts (n=21, mean age=41). The results were as the following figures.Data are expressed as mean±SEM, NTG=nitroglycerineConclusionsThe magnitude of vasoconstrictive response to Ach or Erg was greater at both spastic and nonspastic segments of spasm-related artery compared to control pts. The vasodilatatory response to NTG was also exaggerated in the spasm-related artery. These findings suggest that both basal and stimulated releases of EDRF may be decreased in the spasm related artery. This impaired endothelial function may also be related to the development of coronary spasm in pts with variant angina