Pathological Features of Acute Myocarditis Associated With Takayasu Arteritis

A 24-year-old Japanese woman was admitted with cardiogenic shock and fever. Her laboratory data showed a white blood cell (WBC) count of 14,400/mm³; C-reactive protein level of 9.59 mg/dL; high-sensitivity troponin T level of 0.229 ng/mL, and a N terminal-pro brain natriuretic peptide level of >35,000 pg/mL without septicemia. Electrocardiography showed an inverted T wave in II, III, and aVF leads. Echocardiography revealed diffuse hypokinesis of the left ventricle (LV) with an ejection fraction of 36%. Contrast-enhanced computed tomography showed stenosis of the left subclavian artery (Figure A) and thickened wall of the thoracic (Figure B, arrows) and abdominal aorta (Figure C, arrow). Cardiac magnetic resonance imaging showed a high signal of T2-weighted Black Blood in the LV wall (Figure D). Emergent coronary angiography showed normal coronary arteries. A right ventricular endomyocardial biopsy was performed and it showed cell infiltration and replacement fibrosis (Figure E,F). Infiltrating cells were predominantly composed of neutrophils (Figure G,H) and macrophages (Figure I), followed by CD4-positive T cells (Figure J), CD8-positive T cells (Figure K), and B cells (Figure L). Depositions of immunoglobulin (Ig)G (Figure M), IgA (Figure N), and C1q (Figure O) were detected in intramural vessels and/or interstitium. Those pathological features suggested acute myocarditis associated with Takayasu arteritis. Her conditions were improved after steroid pulse therapy followed by prednisolone (30 mg/day) that was tapered to 15 mg/day for 1 year, and an echocardiography showed LV an ejection fraction of 45%.

Figure.

Enhanced computed tomography (A–C). Cardiac magnetic resonance image (D). An endomyocardial biopsy shows cell infiltration and fibrosis (E, azan ×40; F, hematoxylin and eosin (HE), ×100). Infiltrating cells were more neutrophils (G, HE, ×400). Immunostaining (×200) shows myeloperoxidase-positive cells (H), CD68-positive cells (I), CD4-positive T cells (J), CD8-positive T cells (K), and CD20-positive cells (L) (×200). Immunofluorescence shows depositions of immunoglobulin (Ig)G (M), IgA (N), and C1q (O) detected in intramural arteries (arrows) and/or interstitium (arrow heads) (×200).

Disclosures

K.M. is a member of Circulation Journal’s Editorial Team. All other authors have no conflicts of interest to declare.