case_images: PMC11804243_01
case_images: Main findings in the acute phase. (A and B) TTE showing myocardial thickening and pericardial effusion. (C) GLS of -3.3%. (D) EMB (haematoxylin and eosin staining, bar denotes 50 mum) showing scattered necrotic and fibrotic myocardium with diffuse eosinophilic infiltration. (E) CMR images showing widespread subendocardial LGE (arrows). CMR, cardiac magnetic resonance imaging; EMB, endomyocardial biopsy; TTE, transthoracic echocardiogram; GLS, global longitudinal strain; LGE, late gadolinium enhancement.
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case_images: An electrocardiogram showed a new-onset incomplete left bundle branch block that was absent 6 years prior (see Supplementary material online, Figure S1). Transthoracic echocardiogram (TTE) revealed severe left ventricular systolic dysfunction [left ventricular ejection fraction (LVEF): 32.9%, global longitudinal strain (GLS): -3.3%] with myocardial thickening and pericardial effusion (Figure 1A-C, Supplementary material online, Video S1). On the sixth hospital day, the pathological findings of endomyocardial biopsy (EMB) from the right ventricular septum revealed diffuse eosinophil infiltration, myocardial necrosis, and fibrosis (Figure 1D), confirming eosinophilic myocarditis caused by EGPA. Cardiac magnetic resonance (CMR) imaging showed significant left ventricular subendocardial late gadolinium enhancement (LGE) (Figure 1E).
case_images: Immunosuppressive therapy and optimal medical therapy for heart failure. The patient was treated with prednisolone (PSL), intravenous cyclophosphamide (IVCY), intravenous immunoglobulin (IVIG), and azathioprine as immunosuppressive therapy. Additionally, optimal medical therapy for heart failure with reduced ejection fraction was administered and up-titrated with bisoprolol, eplerenone, sacubitril/valsartan, dapagliflozin, azosemide, and ivabradine. I.V., intravenous; P.O., per os.
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case_images: Additional EGPA-directed treatment with oral corticosteroids, azathioprine, and cyclophosphamide led to a good clinical course (Figure 2).
case_images: Imaging evaluations in the late phase. (A) TTE before discharge showing improvement in left ventricular thickness. (B) CMR disappearance of late gadolinium enhancement. (C) GLS is also improved: -16.4%. (D) EMB (haematoxylin and eosin stain, bar denotes 50 mum) showing remission of eosinophilic infiltration. (E) Impaired GLS remained at 2-year follow-up: -13.7%. CMR, cardiac magnetic resonance imaging; EMB, endomyocardial biopsy; TTE, transthoracic echocardiogram; GLS, global longitudinal strain.
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case_images: C, Supplementary material online, Video S2). Cardiac magnetic resonance showed decreased LGE area (Figure 3B) and eosinophilic stabilization. Although the steppage gait did not improve, the pathological absence of ongoing myocarditis (Figure 3D) prompted the patient's discharge on Day 49 with administration of mepolizumab, an anti-interleukin-5 monoclonal antibody, for mononeuritis.