Short communications: Endothelin-1 in cardiac allograft vasculopathy

Abstract

IntroductionCardiac allograft vasculopathy (CAV) is a leading cause of death following heart transplant. Endothelin-1 (ET-1) is a highly potent vasoconstrictor peptide derived from the vascular endothelium with multiple biological actions known to be relevant for CAV. We assessed the trans-myocardial gradient (TMG: coronary sinus minus coronary artery concentration: negative = extraction, positive = secretion) of ET-1 in heart transplant patients to determine correlations with angiographic, Intravascular Ultrasound (IVUS) and Optical Coherence Tomography (OCT) features of CAV. ResultsVessels with more severe CAV demonstrated significantly higher (more positive) ET-1 TMG (IVUS Stanford Grade IV: −0.05 [−0.21, 0.13] pg/ml versus Stanford Grade I-III: −0.31 [−0.64, −0.11] pg/ml, p = 0.01). ET-1 TMG was positively correlated with mean intimal thickness on both IVUS and OCT (IVUS: Kendall's tau-b = 0.254, p = 0.02 and OCT: Kendall's tau-b = 0.344, p < 0.0001). Patients who died had net ET-1 release compared with surviving patients (died: 0.21 [0.19–0.24] versus surviving: −0.28 [−0.52, −0.17], p = 0.01). ConclusionIn heart transplant patients, coronary arteries with more intimal thickening are associated with a higher (more positive) trans-myocardial gradient of ET-1, suggesting that up-regulated ET-1 release in the coronary circulation may be permissive for the development of CAV.