Hyperhomocysteinemia and transplant coronary artery disease in cardiac transplant recipients

Background: In cardiac transplant recipients, long-term survival may be lim ited by transplant coronary artery disease (TxCAD). Hyperhomocysteinemia (H hcy) has been associated with vascular disease and is common in transplant recipients. The objective of this study was to determine the relationship b etween fasting homocysteine (Hcy) concentrations and TxCAD in a cohort of c ardiac transplant recipients. Methods: Forty-eight patients more than 5 yr after transplant were recruite d from a cohort of 72 consecutive patients with in-depth analysis of homocy steine levels from the Cardiac Transplant Clinic. Early morning fasting blo od was obtained, and the plasma separated and frozen within 30 min. Hcy con centrations were determined by highperformance liquid chromatography (HPLC) with pulsed integrated amperometry. Coronary angiograms were reviewed in a blinded fashion. TxCAD was diagnosed, using the most recent angiogram, whe n a >25% lesion was present anywhere in the coronary tree. Results: Forty-eight patients transplanted between 1985 and 1994 were studi ed. The mean Hcy concentration for the cohort was 23.5 +/- 5.0 mu mol/L, al l patients had homocysteine levels above the upper range of normal (5-15 pm ol/L). Hcy concentrations were significantly higher in patients with angiog raphic evidence of TxCAD: 25.0 +/- 5.9 vs. 21.9 +/- 3.4 mu mol/L, p = 0.03. This effect persisted when covariates were taken into account using logist ic regression analysis. Conclusions: Hhcy is associated with TxCAD. Prospective studies are require d to confirm this association and to assess the efficacy of Hcy-lowering th erapy in this patient population.