1357300 - Diffuse sub-epicardial LGE as a marker of cardiac rejection in patients post heart transplantation- the ring of power

 We report an identical unusual pattern of late gadolinium enhancement (LGE) involving both ventricles, in 3 heart transplant recipients (2 adults and 1 child) who displayed either rapid clinical deterioration or/and rejection (cellular or A-mediated) on subsequent myocardial biopsy.

Patient #1 was a 66-year-old male, 12 years post orthotopic heart transplantation (HT) for DCM with documented vasculopathy and new onset heart failure (HF) and arrhythmias.

Patient #2 was a 65-yearold female, 4 years post HT due to advanced ischaemic heart failure, who again presented with new-onset heart failure and large recurrent pleural effusions. Patient #3 was an asymptomatic 12-year-old boy, 7 years post HT for DCM, who presented for his surveillance post HT evaluation.

Diagnostic Techniques and Their Most Important Findings:

All cases underwent echocardiography and Cardiovascular Magnetic Resonance (CMR). The adult patients manifested severely diminished function (LVEF< 35%), while the pediatric patient had new-onset mild mitral regurgitation, low normal LV systolic function with abnormal diastolic function and significantly echo-bright myocardium. CMR studies revealed diffuse rise of both T1 and T2 values on the respective mapping sequences. Furthermore, CMR illustrated an identical, unique pattern of diffuse subepicardial and pericardial, ring-like Late Gadolinium Enhancement (LGE) engaging both ventricles. Interestingly, patients #2 and #3 had myocardial biopsy proven acute cell and/or Ab-mediated rejection, whereas patient #1 had no evidence of rejection. Despite the negative biopsy result, patient #1 had diffuse luminal irregularities consistent with severe CAV3 on coronary angiography. He eventually experienced severe morbidity with multiple admissions for HF decompensation and arrhythmias that led to ICD implantation.  Patients #2 and #3 were treated for cellular and Ab-mediated rejection with normalization of LVEF and stabilization of clinical status, respectively.

Learning Points from this Case: Such diversity in clinical presentation and diagnostic findings highlights the challenges in managing patients post orthotopic HT. Assessment of myocardial edema via mapping techniques and identification of such ring-like sub-epicardial/pericardial LGE distribution could potentially serve as red flags and assist in prompt recognition of patients who may warrant meticulous work-up to exclude acute myocardial rejection and/or vasculopathy. Further investigation is needed to elucidate the pathogenesis and clinical significance of this specific LGE pattern affecting the entire heart in this less understood population