Transplant vasculopathy is associated with increased AlloMap gene expression score

The AlloMap gene expression test is used for the non-invasive detection of rejection in heart transplant recipients. We evaluated the impact of transplant vasculopathy on AlloMap gene expression analysis. A total of 69 heart transplant recipients, mean age 53 years, were evaluated at a mean 35 months post-transplant. AlloMap score was determined on the same day of the endomyocardial biopsies. Twenty patients had evidence of vasculopathy by coronary angiography (vasculopathy group). These were compared to the remaining 49 patients (control group). The vasculopathy group had a longer mean follow-up duration (48.7 vs 28.8 months, p < 0.01), lower left ventricular ejection fraction (51% vs 60%, p < 0.01) and increased use of sirolimus (40% vs 16%, p = 0.034) compared with controls. Using the logistic regression model and bagging bootstrap approach to adjust for the time factor and potential confounders, the vasculopathy group had a significantly higher AlloMap score than the control group (32.2 +/- 3.9 vs 26.1 +/- 6.5, p < 0.001). There was a correlation of AlloMap score with time after transplantation (r = 0.31, p = 0.01). We found transplant vasculopathy to be associated with increased AlloMap score.