Extensive endomyocardial fibrosis in a patient with cardiogenic shock (QF_SA_122)

Saturday, February 1, 2025

8:10 AM – 8:20 AM East Coast USA Time

Location: Blue Room PreFunction

Presenting Author(s)

MT

Maciej Tysarowski, MD

Fellow
Yale University School of Medicine

Primary Author(s)

MT

Maciej Tysarowski, MD

Fellow
Yale University School of Medicine

Co-Author(s)

XM

Xingchen Mai, MD

Physician
Hartford Hospital
AS

Ayesha Shaik, MD

Fellow
Massachusetts General Hospital
LM

Lara Melo, MD

Resident Physician
University of Connecticut
MO

MIchael O'Loughlin, MD

Physician
Hartford Hospital
SM

Srinivas Mandavilli, MD

Physician
Hartford Hospital
KD

Kevin Duran, RT

MRI Technologist
Hartford Hospital
VN

Vidya Nadig, MD

Cardiologist
Hartford Hospital

Description of Clinical Presentation: A 57-year-old Caucasian male with a history of chronic systolic heart failure and persistent atrial fibrillation presented with worsening dyspnea. Upon admission, his vital signs were stable. Physical examination revealed a thin man with jugular venous distention, no pulmonary rales, and absence of lower extremity edema. Laboratory tests, including a complete blood count and metabolic panel, were unremarkable, except for an elevated NT-proBNP. ECG demonstrated atrial fibrillation with low-voltage QRS complexes and an incomplete right bundle branch block.

Diagnostic Techniques and Their Most Important Findings:
Transthoracic echocardiography revealed a left ventricular ejection fraction (LVEF) of 35-39%, a left ventricular end-diastolic diameter of 5.3 cm, septal and posterior wall thickness of 1.0 cm and 0.9 cm, respectively, moderate right ventricular dysfunction, and severe functional mitral and tricuspid regurgitation.
Invasive hemodynamics via left and right heart catheterization revealed non-obstructive coronary artery disease, an elevated pulmonary capillary wedge pressure, and a modified Fick cardiac index of 1.5 L/min/m². Serum studies demonstrated kappa and lambda light chains of 19.0 mg/L and 6.6 mg/L, respectively, with a kappa/lambda ratio of 2.88. Serum immunofixation confirmed a monoclonal IgG kappa band.
A Tc-99m HDP scan for amyloidosis was equivocal, with a semi-quantitative visual score of grade 1. Cardiac MRI with contrast demonstrated a left ventricular ejection fraction (LVEF) of 42%, right ventricular ejection fraction (RVEF) of 39%, and extensive endomyocardial late gadolinium enhancement involving the basal, mid, and distal segments of the left ventricle as well as the right ventricle. Global extracellular volume (ECV) was significantly elevated at 43%.
Endomyocardial biopsy revealed areas of myocardial and subendocardial fibrosis. Congo red staining was negative for amyloid, and no granulomas or evidence of myocarditis were present. The patient subsequently underwent heart transplantation. Pathological analysis of the explanted heart showed extensive endomyocardial fibrosis throughout the entire heart, with thrombi and foci of calcification along the left ventricular wall. No evidence of myocarditis or amyloid deposition was found.

Learning Points from this Case:
The leading differential diagnosis for the pattern of scarring seen on cardiac MRI is endomyocardial fibrosis. Cardiac amyloidosis was also considered, given the extensive subendocardial late gadolinium enhancement and elevated extracellular volume (ECV); however, the absence of increased wall thickness made this diagnosis less likely. Arrhythmogenic right ventricular cardiomyopathy (ARVC) was another differential, given the dilated right ventricle with an indexed end-diastolic volume of 115 mL/m². However, the lack of right ventricular free wall dyskinesis or microaneurysms made ARVC less probable.
The exact etiology of the patient's endomyocardial fibrosis remains unclear, as is often the case with this condition. Endomyocardial fibrosis is more prevalent in tropical regions of Africa, Asia, and South America and is rare in the United States. It has been associated with systemic parasitic infections, sarcomas, carcinomas, lymphomas, autoimmune processes, and genetic factors.