Loeffler's Endocarditis and Hypereosinophilic Syndrome

In-Depth Review of Loeffler Endocarditis: What Have We Learned?

Loeffler endocarditis, eosinophilic endocarditis or eosinophilic endomyocardial disease are conditions associated with hypereosinophilia and they affect the heart function. Loeffler endocarditis is a rare endomyocardial disorder thought to be caused by eosinophilic damage. The disorder is characterized by inflammatory infiltration, formation of thrombus within cardiovascular system, and ultimately fibrosis of the afflicted area. It can lead to multiple severe complications, including thromboembolic disease, thickening of fibrous tissue in the endocardium of ventricles, valve involvement, apical obliteration, and various heart disorders. Although early clinical intervention can lead to remission, the underlying mechanisms of the disorder remain unresolved. In the present article, we summarise the existing literature concerning Loeffler endocarditis based on PubMed, Web of Science, and other medical databases to conduct an in-depth review of the epidemiology, etiology, pathophysiological mechanisms, staging, diagnosis, treatment and prognosis of Loeffler endocarditis. Meanwhile, we provide novel patients data and clinical figures of Loeffler endocarditis to supplement the understanding of this cardiac disorder. The findings presented in this article provide a basis for further studies and can be used to improve management of the disorder.

Eosinophilic myocarditis from a forensic histopathological perspective

Eosinophilic myocarditis (EM) is a rare and potentially fatal form of myocarditis characterized by infiltration of the myocardium with eosinophil leukocytes, often accompanied by eosinophilia. Although the exact underlying cause remains unknown, it has been shown to be associated with hypersensitivity reactions, immune-mediated disorders, infections, or cancer. Due to the differences in symptomatology, it is often diagnosed by postmortem histopathological examination. We aimed to retrospectively examine the histopathological findings of rare cases of EM and to detect accompanying cardiac and other organ pathologies. The histopathological findings of the cases that underwent autopsies between 2012 and 2020 and were diagnosed with EM were assessed. Demographic features, symptoms, causes of death, macroscopical findings at autopsy, toxicologic and microbiological analysis results, accompanying cardiac pathologies, and histopathological findings in other organs were evaluated. Myocarditis was detected on histopathologic examination in 558 (1.1%) of 49,612 forensic autopsies. There were 12 (2.3%) EM cases. There were nine males and four females. The mean age was 42.3 (3-83) years. Heart weights ranged from 82 to 564 g. The most common finding on macroscopic examination was the mottled discoloration and scarring in the myocardium. Microscopic examination revealed perivascular and interstitial infiltration of eosinophils in all of the cases accompanied by myocyte necrosis in four of them. EM was reported as the cause of death in four cases. EM remains a challenging heart disease with its obscure etiopathogenesis and varying clinical presentation and a rare entity diagnosed by postmortem histopathological examination in sudden and unexpected deaths.

Case report: Different clinical manifestations of the rare Loeffler endocarditis

BACKGROUND

Loeffler endocarditis is a rare and fatal disease, which is prone to be misdiagnosed, owing to its various clinical manifestations. Consequently, an early identification of Loeffler endocarditis and its effective treatment are crucial steps to be undertaken for good prognosis.

CASE PRESENTATION

This report describes two cases of Loeffler endocarditis with different etiologies and clinical manifestations. Case 1 was caused by idiopathic eosinophilia and presented with a thrombus involving the tricuspid valve and right ventricular inflow tract (RVIT). The patient suffered from recurrent syncope following activity. After the patient underwent tricuspid valve replacement and thrombectomy, he took oral prednisone and warfarin for 2 years, consequent to which he discontinued both drugs. However, the disease recurred 6 months later, this time manifesting as edema of both legs. Echocardiography showed that a thrombus had reappeared in the RVIT. Thus, oral prednisone and warfarin therapy was readministered. Three months later, the thrombus had dissolved. Low-dose prednisone maintenance therapy was provided long term. Case 2 involved a patient who presented with recurrent fever, tightness in the chest, and asthma, and whose condition could not be confirmed, despite multiple local hospitalizations. In our hospital, echocardiography revealed biventricular apical thrombi. After comprehensive examinations, the final diagnosis was eosinophilic granulomatosis polyangiitis (EGPA) involving multiple organs, including the heart (Loeffler endocarditis), lungs, and kidneys. After administration of corticosteroid, anticoagulant, and immunosuppressive agents along with drugs to improve cardiac function, the patient's symptoms improved significantly.

CONCLUSION

In Loeffler endocarditis due to idiopathic eosinophilia, long-term corticosteroid use may be required. Diverse and non-specific symptoms cause Loeffler endocarditis to be easily misdiagnosed. So, when a patient shows a persistent elevation of the eosinophil count with non-specific myocardial damage, the possibility of this disease, should always be considered. Furthermore, even when an invasive clinical procedure such as endomyocardial biopsy (EMB) is not available or acceptable, corticosteroids should be administered promptly to bring the eosinophil count back to the normal range, thereby halting the progression of disease and reducing patient mortality.

Left Ventricular Assist Device Evaluation for Congestive Heart Failure With Hypereosinophilic Syndrome in a 76-Year-Old Male

Hypereosinophilic syndrome, a rare condition, is characterized by eosinophilia with associated organ infiltration and organ failure. The most commonly involved sites include the cardiovascular, gastrointestinal, and central nervous systems. Infiltration of eosinophils into the myocytes may result in congestive heart failure warranting the use of a left ventricular assist device (LVAD). The authors describe a case of a 76-year-old male with dyspnea and a consistently elevated eosinophil count. Initially diagnosed with adult-onset asthma, he failed to improve despite his adherence to recommended pharmacological treatment. The exacerbation of dyspnea combined with the signs of congestive heart failure led to the evaluation of LVAD therapy in this patient.

Case report: Application of non-VKA oral anticoagulants in patient of idiopathic hypereosinophilic syndrome with intracardiac thrombus

Idiopathic hypereosinophilic syndrome (IHES) is a rare but life-threatening disease related to a group of myeloproliferative disorders characterized by prolonged eosinophilia of unknown cause and inflammatory damage to multiple organs. Here, we present a 44-year-old female patient complaining of shortness of breath and palpitations for 1 month. Her history and presentation were unremarkable, except for a 3-years history of rheumatoid arthritis treated with ibuprofen (0.3 g per day). Initial examination showed heart rate (HR) 120 bpm, respiratory rate (RR) 20 bpm, temperature (T) 36°C, blood pressure (BP) 130/70 mmHg, ventricular gallop rhythm, rales at the lung bases, soft abdomen, nonpalpable liver and spleen, and slight edema in both lower extremities. Bone marrow aspirate and biopsy confirmed the diagnosis of IHES, while cardiac MRI showed intracardiac thrombus. The symptoms of shortness of breath and palpitation disappeared, the eosinophil counts in routine blood tests were normal, and the thrombus in the cardiac cavity gradually disappeared after combined therapy of anti-hypereosinophilic, anti-coagulant and anti-heart failure treatments.