The Safety of a Non-Invasive Monitoring Protocol in Heart Transplant Recipients

Abstract

<h3>Purpose</h3> Heart transplant (HT) recipients require monitoring for allograft rejection with frequent endomyocardial biopsies (EMB). The aim of this study was to evaluate the safety of transitioning heart transplant recipients to a non-invasive monitoring protocol utilizing HeartCare (combination of gene expression profiling [Allomap] and donor derived cell free DNA [Allosure]). <h3>Methods</h3> This is a prospective single-center cohort study evaluating the utilization of HeartCare from as early as one month post-HT. Positive Allomap test was defined as ≥32 in patients ≤6 months and ≥34 in patients > 6 months post-HT. Positive Allosure test was defined as ≥0.12%. Positive biopsy included ISHLT Grades ≥1B. <h3>Results</h3> 320 heart transplant recipients enrolled to this study. Mean age was 57.5±14.0, 231 were males (72.0%). There was a total of 523 HeartCare blood tests drawn and 148 biopsies were performed (Figure). Of 82 patients with elevated Allomap and Allosure, only 7 (8.5%) of them had a confirmed rejection episode. Among 71 patients with elevated Allosure with normal Allomap, only 2 (2.8%) patients had confirmed rejection. 2 patients (4.3%) with negative Allomap and Allosure had rejection. During the study period 55 patients (17.2%) were admitted to the hospital for a total of 67 admissions. 17 patients were admitted for rejection (5.3%). None of the patients died during the study period. <h3>Conclusion</h3> Transitioning from invasive endomyocardial biopsy monitoring to a non-invasive HeartCare protocol in HT recipients seems feasible based on the high negative value of the combined Allomap and Allosure tests. However, further study is needed to follow the long-term outcomes and presence of rejection in patients post-transplant with this protocol.