Discussion
There are obvious individual differences in the clinical manifestations
of HES, ranging from asymptomatic, multiple organ involvement, and even
death. This pathology may involve many organs and systems, such as the
skin, lungs, nervous system, gastrointestinal tract, kidneys, and heart.
Therefore, diagnosis may be a challenge. The main morbidity and
mortality of HES patients are mostly cardiovascular
complications.[2] Heart involvement may be present in 50% to 60%
of patients, this is called Loffler endocarditis.
Due to infiltration and degranulation of eosinophils, toxic proteins are
released, causing tissue inflammation and late fibrosis resulting in
secondary damage to the myocardium and endocardium. It is usually
characterized by thickening of the endocardium and dilation of the
atrium. Doppler echocardiography can show hyperechoic mass in the heart
cavity, suggesting fibrosis or thrombosis, and is often located in the
apical area of the left and right ventricles. [3],[4]
Echocardiography and imaging studies may be the main tools for assessing
cardiac anatomy and function. However, Loffler endocarditis requires
pathological diagnosis, so endocardial biopsy remains the gold standard.
In some cases, myocardial biopsy may be a dangerous operation.
Therefore, clinicians should personally evaluate each individual before
performing such invasive procedures. In addition, when evaluating the
possibility of Loffler endocarditis, it is important to exclude the main
differential diagnosis of HES, including hyper eosinophils secondary to
hypersensitivity and parasitic infections. In this case, preoperative
laboratory studies showed peripheral hyper eosinophilia and
echocardiography showed typical intraventricular space-occupying
changes. The diagnosis of Loffler endocarditis is basically established,
and postoperative pathological specimens have confirmed the previous
diagnosis. The pathological features of Loffler’s endocarditis include
thickening of endocardial fibers, leading to a decrease in cardiac
volume, thrombosis and restrictive cardiomyopathy. The clinical
manifestations are heart failure, thromboembolic events and atrial
fibrillation.
The main purpose of treatment is to reduce the level of eosinophils in
peripheral blood and tissues, prevent terminal organ damage, and avoid
the occurrence of adverse thrombotic events. Heart failure in Loffler’s
endocarditis is mainly due to limited diastolic function of the heart.
Treatment includes intravenous diuretics to reduce the preload of the
heart. In addition, for symptomatic patients, the first-line drugs of
choice are corticosteroids, followed by cytotoxic drugs such as
hydroxyurea, and immunomodulators such as alpha-interferon.
Glucocorticoid therapy is clinically proven to be effective for HES,
which can improve the condition of myocardial injury and normalize
peripheral hyper eosinophilia.[5],[6]
Secondary treatment should target cardiac complications such as heart
failure and the presence of intracardiac thrombosis. Sometimes,
cardiovascular complications require surgical treatment. Surgical
experience is limited to cases where the heart valve function of
patients due to HES is affected, but in more serious cases, acute
surgical intervention may be necessary. In this case reported by our
center, due to the large amount of thrombus tissue filling the right
ventricle in a short time, the volume of the right ventricle was
significantly reduced, the tricuspid valve was wrapped in the thrombus
tissue, the opening of tricuspid valve was restricted, and there was a
risk of pulmonary embolism caused by thrombosis. Therefore, the heart
thrombus was removed under emergency cardiopulmonary bypass surgery.
Our patient had a good prognosis
during the follow up of half year. She had no symptoms of heart failure
and echocardiography findings were normal. This result might be due to
the proper operation as well as the control of peripheral eosinophilia
before and after the surgical procedure. Loffler endocarditis caused by
hyper eosinophilia syndrome is unusual and fatal in children.
The present case illustrates that
with well controlled peripheral eosinophilia, proper
surgical treatment in selected
patients can improve their prognosis in the near future but long-term
follow up is necessary.
Ethics approval This study has been approved by Medical Ethics
Committee of Beijing Children’s Hospital, Capital Medical University and
the composition and procedure of Medical Ethics Committee is accordance
with GCP principal and national relevant laws and regulations
Number:2020-Z-062