Intimal hyperplasia and coronary flow reserve after heart transplantation: association with big endothelin-1

Abstract

Background Endothelin, a peptide with strong vasoconstrictive and mitogenic properties, has been found to increase after cardiac transplantation. We therefore assessed the association between its precursor peptide, big endothelin-1, and intimal hyperplasia and coronary flow reserve after heart transplantation. Methods Thirty-five patients without hemodynamically significant coronary artery disease after heart transplantation were investigated: Average peak flow velocity in the left anterior descending artery (LAD) was assessed by intracoronary Doppler at baseline as well as after injection of adenosine; coronary flow reserve was calculated as a ratio of both and was corrected for patient age and baseline average peak flow velocity. Lumen, intima + media and total vessel area were measured by intracoronary ultrasound. The plasma concentration of big endothelin-1 in venous blood was determined by radioimmunoassay. Results Patients with elevated big endothelin-1 levels (>2 fmol/ml) tended to have a decreased corrected coronary flow reserve (2.60 ± 0.9 vs 3.21 ± 1.0, p = 0.078). They also had a significantly larger intima + media area (5.82 ± 2.9 vs 2.37 ± 2.9 mm 2, p = 0.004) and total vessel area (18.36 ± 5.8 vs 12.81 ± 4.8 mm 2, p = 0.012) than those with normal plasma concentrations. Conclusions Our study suggests an association between elevated big endothelin-1 plasma levels and the development of intimal hyperplasia and reduction of coronary flow reserve after cardiac transplantation. J Heart Lung Transplant 2002;21:000–000.