1357736 - Heart transplant Evaluation with Propensity score-matched case-control Analysis Through non-Invasive Tissue Imaging with Stress Cardiac Magnetic Resonance (The HEPATITIS CMR study)

Hepatitis C Virus positive (HCV+) donors offer a viable strategy for expansion of the heart donor pool without an associated increase in 1-year recipient mortality. Cardiac magnetic resonance imaging (CMR) is an effective tool for graft surveillance in heart transplant recipients. However, there are no data comparing CMR for evaluation of graft performance in heart transplant (HT) recipients based on donor HCV status. The objective of this study was to establish baseline CMR characteristics for the HCV+ HT cohort and explore findings that might reflect detrimental effects of donor-derived HCV infection. 



Methods:

We conducted a single center propensity score matched case-control study comparing cardiac allograft structure, function, performance, and tissue characterization among HCV+ HT recipients (cases) versus HCV- HT recipients (controls) undergoing non-invasive graft surveillance with a comprehensive stress CMR protocol at our institution from September 2019 through June 2021. All cases included in the HCV+ HT group developed HCV viremia post-HT and were subsequently treated with direct-acting antiviral therapies.  For each HCV + HT patient, propensity score matching using nearest neighbor was utilized to identify a matching control with replacement based on donor age, coronary artery vasculopathy (CAV) grade, time from transplant to CMR, and number of treated rejection episodes. Matched cohorts’ CMR phenotype was compared by volumetrics, functional analysis, strain and LGE using Wilcoxon signed-rank tests. Parametric mapping (native T1, T2, and extracellular volume (ECV)) were compared using unmatched cohorts due to missingness of data.



Results:

23 HCV+ HT patients and 34 HCV- HT controls met inclusion/exclusion criteria, with mean interval from transplant to CMR of 717 days. Baseline characteristics between unmatched cohorts are demonstrated in Table 1. Comparison of CMR phenotypes is presented in Table 2. Volumetric analysis demonstrated similar biventricular function, with cases having increased LV mass (LV mass index: 58.4 vs. 57.0 g/m², p=0.021) and increased RV end-diastolic volumes (RVEDVi 63.2 vs. 51.6, p=0.0052) compared to controls.  Cases and matched controls had similar global longitudinal strain (GLS: -17.9 vs. -18.8, p=0.52) and global circumferential strain (GCS: -24.2 vs. -22.6, p=0.23). The extent of LGE both quantitatively and qualitatively did not significantly differ between groups. Myocardial tissue characterization performed on unmatched cohorts with parametric mapping (T1, T2, and ECV) was similar between cases and controls as well, shown in Figure 1.



Conclusion:

Among propensity-matched recipients of HCV+ donor hearts as compared to HCV- hearts, there was no significant difference in biventricular function, strain, or LGE. Among unmatched recipients and controls, there was no significant difference in myocardial tissue characteristics by parametric mapping. This study demonstrates that the CMR phenotype is similar between HCV+ and HCV- recipients.