Hyperhomocysteinaemia in heart transplant recipients

The aim of this study was to determine the prevalence of hyperhomocysteinaemia in cardiac transplant recipients. Three groups of subjects were studied: 27 heart transplant recipients, 14 to 63 months (mean = 36.5) after transplantation; 10 patients with moderate chronic renal insufficiency without clinical evidence of vascular disease; 17 apparently healthy individuals. Twenty-five out of 27 transplanted patients had a coronaroangiography within 6 months of homocysteine measurement. Plasma homocysteine was measured both while the subject was fasting (t0) and 6 h after administration of 0.1 g.kg-1 of methionine (t6). Hyperhomocysteinaemia was present in 14/27 fasting transplanted patients and after methionine loading. Mean plasma levels of homocysteine at t0 were higher (P = 0.03) in transplanted heart recipients (15.4 +/- 7 mumol.l-1) than in the renal patients (9.9 +/- 5 mumol.l-1) despite similar mean plasma creatinin. In eight transplanted patients with angiographic coronary abnormalities of the cardiac graft, homocysteinaemia was at t0 17.1 +/- 9 mumol.l-1 and at t6 47.8 +/- 25 mumol.l-1. In 17 transplanted patients with angiographically normal coronary arteries, plasma homocysteine levels were at t0, 13.2 +/- 4 mumol.l-1 and at t6, 46.8 +/- 25 mumol.l-1. We conclude that hyperhomocysteinaemia is common in transplanted heart recipients, and partly related to renal insufficiency. No correlation was found between hyperhomocysteinaemia and angiographic evidence of coronary atherosclerosis of the graft, but the population of the study was possibly too small to establish this correlation.