Background: Vasoconstriction of normal coronary arteries has been reported after intracoronary (i.c.) administration of acetylcholine (Ach) in cardiac transplant patients and has been related to early endothelial disfunction; the clinical correlates of this response are still unknown.
Methods: We infused graded i.c. concentrations of Ach in 32 pts with angiographically smooth coronary arteries 1 to 3 years after heart transplantation. Changes in diameters of the proximal and middle segments of the left anterior descending coronary artery were measured by quantitative coronary angiography (automatic edge detection).
Results: The response to Ach ranged from +44% to -58%; at linear regression analysis it was significantly related to the plasma levels of cyclosporine (r = -0.39, p < .05) and triglycerides (r = -0.42, p < .02) but not to vessel diameter, recipient and donor age, time after transplantation, hypertension, cholesterol levels, number of acute rejection episodes and previous cytomegalovirus infections.
Conclusions: In heart transplant pts with angiographically normal coronary arteries i.c. Ach may reveal endothelial disfunction which is associated with high cyclosporine and triglycerides plasma levels. Whether this response may predict an earlier development of coronary disease remains to be elucidated.