Eosinophilic Myocarditis Demonstrated Using Cardiac Magnetic Resonance Imaging in a Patient with Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Disease)

Eosinophilic myocarditis: systematic review

OBJECTIVE

In clinical practice, patients with eosinophilic myocarditis (EM) may forgo the gold standard diagnostic procedure, endomyocardial biopsy (EMB), although it is highly recommended in guidelines. This systematic review aims to summarise current approaches in diagnosing and treating EM with a particular emphasis on the utilisation and value of alternative diagnostic methods.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, we searched MEDLINE and EMBASE for all peer-reviewed articles using the keywords "eosinophilic myocarditis" from their inception to 10 September 2022.

RESULTS

We included 239 articles, including 8 observational studies and 274 cases, in this review. The median patient age was 45 years. Initial presentations were non-specific, including dyspnoea (50.0%) and chest pain (39.4%). The aetiologies of EM were variable with the most common being idiopathic (28.8%) and eosinophilic granulomatosis polyangiitis (19.3%); others included drug-induced (13.1%) and hypereosinophilic syndrome (12.8%). 82.4% received an EM diagnosis by EMB while 17.6% were diagnosed based on clinical reasoning and cardiac MRI (CMR). CMR-diagnosed patients exhibited a better risk profile at diagnosis, particularly higher left ventricular ejection fraction and less need for inotropic or mechanical circulatory supports. Glucocorticoids were the primary treatment with variability in dosages and regimens.

CONCLUSION

EMB is the mainstay for diagnostic testing for EM. CMR is potentially helpful for screening in appropriate clinical scenarios. Regarding treatment, there is no consensus regarding the optimal dosage of corticosteroids. Large clinical trials are warranted to further explore the utility of CMR in the diagnosis of EM and steroid regimen in treating EM.

The Diagnostic Challenge of Eosinophilic Granulomatosis With Polyangiitis Presenting as Acute Eosinophilic Myocarditis: Case Report and Literature Review

Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis involving small-to-medium-sized vessels characterized by asthma, vasculitis, and peripheral eosinophilia. EGPA-associated eosinophilic myocarditis (EM) occurs rarely, yet can be fatal if left untreated. Moreover, the accurate diagnosis of EGPA-associated EM without vasculitis is exceptionally difficult because of the overlapping features with EM of other causes. We report a case of probable EGPA with subclinical neurological involvement that presented with acute EM. The constellation of peripheral eosinophilia, left ventricular dysfunction, and normal epicardial coronary arteries raised suspicion of acute EM, which was confirmed by cardiac magnetic resonance (CMR) investigation and endomyocardial biopsy (EMB). Prompt systemic administration of corticosteroids completely restored and normalized myocardial structure and function. Although the patient's history suggested the presumed hypersensitivity myocarditis, EMB revealed EM without vasculitis, not hypersensitivity, leading to a tentative diagnosis of idiopathic hypereosinophilic syndrome. Interestingly, the characteristic findings of vasculitis on CMR imaging strongly suggested EGPA-associated EM. Although the patient had no clinical neurological manifestations, a nerve conduction study confirmed mononeuritis multiplex, leading to the final diagnosis of probable EGPA. Therefore, this case highlights the diagnostic challenge associated with EGPA and the diagnostic synergy of CMR and EMB for an exploratory diagnosis of EGPA-associated EM.

Cardiac Involvement in Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Disease): The role of cardiovascular magnetic resonance

Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as Churg-Strauss disease, is a rare vasculitis that affects small- to medium-sized vessels and has a propensity to involve the heart. Patients with cardiac involvement have a poor prognosis and usually require immunosuppressive treatment along with corticosteroids. Cardiovascular magnetic resonance (CMR) is a non-invasive diagnostic tool for detecting cardiac involvement and guiding the management plan. We report a 39-year-old male patient with a known history of bronchial asthma who was referred to the chest clinic at a tertiary hospital in 2019 for further assessment of persistent lung parenchymal changes on chest computed tomography. Given the clinical context of the patient and the radiological findings, EGPA was suspected and confirmed with a lung biopsy. CMR was performed for further assessment, which confirmed cardiac involvement. The patient was started on prednisolone and azathioprine and showed significant radiological and clinical improvement.

The Critical Role of Cardiac Magnetic Resonance Imaging in Evaluating Patients With Eosinophilic Granulomatosis With Polyangiitis

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare autoimmune systemic necrotizing vasculitis of blood vessels that often presents with hypereosinophilia. Cardiac involvement in EGPA directly correlates with the mortality of patients with the disease and is a central part of the disease process. The evaluation and treatment of cardiac anomalies are vital in patients with EGPA. The frequency with which cardiac involvement is seen in the disease process makes early diagnosis crucial in all patients with EGPA. Early treatment has been proven to reverse or cause the disease to go into remission. Several studies have shown that cardiac magnetic resonance (CMR) imaging is the most sensitive and best early indicator of cardiovascular involvement in EGPA. CMR routinely outperforms other diagnostic techniques such as ECG (echocardiography) and CTA (computed tomography angiography) in the detection of cardiac anomalies and should be a part of the standardized assessment of all patients with EGPA. CMR is also a non-invasive diagnostic tool that can also outperform biopsy in the detection of EGPA cardiac involvement. CMR is also a valuable technique that can be used to monitor disease progression while treatment is being performed. Although long-term research studies have yet to show these benefits, the studies that are available today provide ample evidence that shows CMR imaging could ultimately help bring down mortality rates currently seen in EGPA patients if it is used as an evaluation tool from initial diagnosis and throughout the entire course of disease management.

Myopericarditis as a presentation of eosinophilic granulomatosus with polyangiitis (EGPA)

A 60-year-old woman was admitted to the hospital with worsening dyspnoea, cough and chest pain. This was on a background of weight loss, decreased appetite, mononeuritis multiplex, chronic eosinophilia and a single episode of a non-blanching rash. Investigations demonstrated a raised troponin and ischaemic changes on ECG, and she was therefore initially treated for a presumed myocardial infarction. However, her symptoms failed to improve with treatment for the acute coronary syndrome. A coronary angiogram revealed no significant flow-limiting disease, and further investigations yielded confirmation of raised eosinophils and a positive perinuclear antineutrophil cytoplasmic antibody test. An echocardiogram demonstrated a pericardial effusion, and subsequent cardiac magnetic resonance features were compatible with myopericarditis. In light of these findings, the patient was diagnosed with eosinophilic granulomatous with polyangiitis and commenced on high-dose intravenous methylprednisolone and cyclophosphamide. She made an excellent recovery and remains in remission on azathioprine and a tapering dose of corticosteroids.