Abstract
PURPOSE: A link between SARS-CoV2 infection and myocardial injury has been described. Our center utilizes non-invasive surveillance with gene expression profiling and donor-derived cell-free DNA (dd-cfDNA) in heart transplant (HTx) patients who are either stable or in whom invasive surveillance is contraindicated. We evaluated whether HTx recipients diagnosed with SARS-CoV2 infection demonstrated evidence of myocardial allograft injury using dd-cfDNA. METHODS: HTx recipients were included if they had dd-cfDNA testing (AlloSure; CareDx Inc., Brisbane, CA) within 60 days of their initial SARS-CoV2 diagnosis. Data on hospitalization, therapy, and clinical outcomes was captured. Dd-cfDNA results at the assay limit of detection (LOD, <0.12%) were set equal to the LOD. RESULTS: Between 3/2020 and 6/2021, we identified 12 HTx recipients with SARS-CoV2 and dd-cfDNA results within the specified time period; median age was 55 (IQR 28 - 64.5) with infection occurring 506.5 days (IQR 176 - 803.5) after transplant. Mean dd-cfDNA was 0.13 ± 0.03%, assessed 26 (IQR 20 - 35) days after infection. Prior results, available for 9 patients and obtained a median of 33 (IQR 27 - 59) days prior to infection, did not differ from post-infection values (0.13 ± 0.02%, p = 0.66). Following diagnosis, 8 (67%) patients were hospitalized; 5 had mycophenolate held, 2 received steroids, 2 received convalescent plasma, 4 received remdesivir, and 1 received monoclonal Ab therapy. At a median follow-up time of 304 (IQR 212.5 - 331) days after diagnosis, all twelve patients were alive with good allograft function (mean ejection fraction 59 ± 4.8%); interval clinically-relevant immunologic outcomes included one episode of rejection (pAMR1) and three (25%) findings of de novo donor-specific antibodies (dnDSA). CONCLUSION: In this single-center pilot study assessing myocardial injury among HTx recipients within 2 months of SARS-CoV2 infection, the majority of patients had low dd-cfDNA results (<0.15%) and demonstrated good intermediate-term (6-12 months) graft function. While limited by sample size and protocol-based inclusion criteria, our findings suggest that sustained myocardial injury in HTx recipients after SARS-CoV2 infection may not be common. The impact of SARS-CoV2 infection on immunologic outcomes including rejection and dnDSA in this population merit further study.