Libman- Sacks endocarditis was first described in 1924 by Emanuel Libman and Benjamin Sacks in New York in four patients (Ibrahim 2022).
The term "endocardial fibroelastosis" (EFE) was coined in 1943 by Weinberg et al. Previously, the disease had been referred to as "fetal endocarditis" (Sana 2022).
In 1936, W. Löffler was the first to describe "Löffler endocarditis," named after him (Mubarik 2022).
Abacterial endocarditis is an inflammation of the endocardium caused by autoimmunological processes or by thrombotic deposits due to coagulation disorders in the context of serious general diseases (Buchta 2004).
Abacterial endocarditis may present as:
- E. rheumatica (also known as E. verrucosa):
This form of endocarditis occurs as an allergic reaction to infection with beta-hemolytic A streptococci (Schaps 2007).
This is the cardiac manifestation of systemic lupus erythematosus. Sterile vegetations of the heart valves are typically found, which carries a significant risk for additional infective endocarditis (Ramiandrisoa 2019).
- Endomyocarditis eosinophilica (also referred to as "Löffler's endocarditis" or "Marantic endocarditis"):
This disease represents a restrictive cardiomyopathy triggered by eosinophilia (Mubarik 2022). A distinction is made between an acute and a subacute form of the disease (Herold 2022).
- Mixed form:
In the mixed form, an additional infective endocarditis occurs on the floor of an abacterial endocarditis (Herold 2022).
The incidence of noninfectious thrombotic endocarditis (NITE) was 3.7% in a large autopsy series by Bussani et al. NITE is more common in preexisting valve lesions and is often associated with malignant neoplasms, liver cirrhosis, autoimmune diseases, tuberculosis, or a hypercoagulated state (Sekar 2021).
- E. rheumatica(verrucosa):
It is among the most common form of abacterial endocarditis and occurs approximately 1 - 3 weeks after infection with beta-hemolytic A- streptococci (Herold 2022). Most acquired valvular heart disease is due to rheumatic endocarditis (Buchta 2004).
E. rheumatica is particularly common in developing countries (Sekar 2021).
It is one of the rarely occurring diseases (Sadeghpour 2021) and occurs in 6-11% of patients with systemic lupus erythematosus , according to autoptic studies even in up to 50%. In the setting of malignancies, the prevalence is 1.25% (prevalence of the general population is 0.25%). Together with antiphospholipid syndrome, it shows a prevalence of 33% (Ibrahim 2022).
- Endomyocarditis eosinophilica:
This disease represents a rare manifestation of hypereosinophilic syndrome (HES) . The annual incidence is 0.036 patients per 100,000, and the disease occurs preferentially in temperate and tropical areas of Asia, Africa, and some areas of South America. There is no gender predisposition (Mubarik 2022).
- E. rheumatica (verrucosa):
It represents a disease caused by beta-hemolytic A- streptococci and a partial manifestation of pancarditis, both of which may occur as complications of rheumatic fever (Herold 2022).
It is usually caused by systemic lupus erythematosus (SLE) (Herold 2022). However, it is also found in association with malignancies and antiphospholipid syndrome (Ibrahim 2022).
- Endomyocarditis eosinophilica:
This disease is a restrictive cardiomyopathy, the cause of which is as yet unknown (Mubarik 2022).
It can occur in the context of various diseases such as bronchial asthma, Hodgkin's and non-Hodgkin's lymphomas, eosinophilic leukemia, idiopathic hypereosinophilia, polyarthritis nodosa, lung carcinoma (Herold 2022).
The pathology of abacterial endocarditis is unclear to date. Endothelial injury in the context of a hypercoagulable state seems to play a role in the initial development, as do interleukins. Both may lead to deposition of platelets and inflammatory molecules in the area of the affected heart valves (Ibrahim 2022).
- E. rheumatica (verrucosa):
This occurs preferentially at the closure margins of the mitral and aortic valves (Herold 2022). There may be stenosis of the affected valve(s) due to vascular sprouting and connective tissue scarring. If vertical shrinkage of the valve occurs, insufficiency of the valve leaflets results (Lohr 2002).
In this case, larger fibrin droplets, so-called verrucous valve abnormalities (Kasper 2015) are most commonly found on the mitral, aortic, and pulmonary valves (Herold 2022).
These lesions may embolize or become infected but rarely cause hemodynamically significant valve regurgitation (Kasper 2015).
Accompanying E. Libman- sacks is often pleurisy and pericarditis (Herold 2022).
- Endomyocarditis eosinophilica:
It predominantly affects the endocardium of the right ventricle. The wall of the endocardium becomes thickened by cellular infiltration of eosinophilic granulocytes (Herold 2022).
- E. rheumatica (verrucosa):
In addition to the symptoms of rheumatic fever (see d.), fever and wandering pain of the large joints reappear. Auscultatory findings include a new-onset heart murmur (Braun 2022). There may also be symptoms of valve damage (see also mitral stenosis / mitral regurgitation / aortic stenosis / aortic reg urgitation [Buchta 2004]), chorea minor (rarely occurs), subcutaneous rheumatoid nodules, erythema nodosum, erythema anulare marginatum (Braun 2022; Buchta 2004).
The disease is usually asymptomatic. The most common initial presentation is systemic thromboembolism (Sadeghpour 2021).
- Endomyocarditis eosinophilica:
In approximately 60% of cases, patients complain of dyspnea followed by thoracic pain, cough, fatigue, and weight loss (Mubarik 2022). There may also be signs of acute heart failure and arrhythmias, which can be life-threatening. Similarly, intracardiac thrombus may occur (Mubarik 2022).
The diagnosis of NITE is usually considered in patients with repeated blood culture negative endocarditis. In > 75% of cases, NITE is associated with systemic lupus erythematosus or malignancy. From there, history and investigations with special focus on extracardiac manifestations (especially computed tomography and echocardiography) are directional (LeBot 2018).
E. rheumatica (verrucosa):
Detailed history (beta-hemolytic streptococcal A- infection present 8 - 14 days previously), laboratory findings (Braun 2022).
In cases of Libman Sacks endocarditis, in addition to the usual laboratory tests, hypercoagulation should also be investigated, as well as lupus anticoagulant and determination of antiphospholipid antibodies.
At least 3 sets of blood cultures should also be taken.
Definite detection can only be achieved by platelet thrombus detection (Ibrahim 2022).
Endomyocarditis eosinophilica:
The gold standard of diagnosis is endomyocardial biopsy. Because this is associated with significant risks, clinicians prefer cardiac magnetic resonance imaging (see "Imaging") (Mubarik 2022).
Transthoracic echocardiography
In cases of suspected abacterial endocarditis, a two-dimensional transthoracic echocardiography (TTE) should be performed first. This reveals vegetations of the valves, especially on the left side (Ibrahim 2022).
Transesophageal echocardiography:
Because both sensitivity and specificity are significantly higher with this examination than with transthoracic echocardiography, transesophageal examination should always be performed in cases of suspected abacterial endocarditis (Ibrahim 2022). Here, detectable may be:
- irregular borders
- heterogeneous echo density
- absence of independent motion (suggestive of verrucous vegetations)
- Regurgitations of the affected valve(s) (Ibrahim 2022).
Cardiac Magnetic Resonance Tomography (CMR)
This plays a particularly important role in the diagnosis of endomyocarditis eosinophilica because it is more specific than transthoracic and transesophageal echocardiography with regard to the diagnosis of ventricular mural thrombus (Mubarik 2022).
CMR with gadolinium should be performed to differentiate between inflammation and fibrosis, as in this case the intensity of delayed enhancement is more evident in fibrosis than in inflammation (Mubarik 2022).
- E. rheumatica (verrucosa):
- ESR elevation
- CRP increase
- Antistreptolysin titer (detectable in 80 %, but not suitable as a progression parameter) (Braun 2022)
In this case, clinical and laboratory signs of inflammation are typically absent. Blood cultures are negative (Sadeghpour 2021).
- Endomyocarditis eosinophilica:
This is characterized by hypereosinophilia (Salih 2021). E. eosinophilica is always associated with an increase in eosinophil granulocytes (Herold 2022). This usually persists for up to 6 months after the onset of the disease (Mubarik 2022).
The vegetations consist primarily of:
- mononuclear cells
- fibrin
- platelet thrombi (Ibrahim 2022).
E. rheumatica (verrucosa):
- Detection of fibrin and platelet aggregation (Sekar 2021).
- Active verrucae consist of:
- Fibrin clots with focal necrosis.
- healed lesions consisting of:
- vascularized dense fibrous and scar tissue (Ibrahim 2022).
Endomyocarditis eosinophilica:
- Thickening of both ventricles due to fibrosis
- degranulated eosinophilia and eosinophil cationic protein in the endocardium
- activated eosinophilia in the myocardial interstitium
- large mural thrombi may be present in both right and left ventricles
- inflammation of the small intramural coronary vessels (Mubarik 2022)
- E. rheumatica (verrucosa):
- Bacterial endocarditis (Burg 2008).
- bacterial endocarditis
- tumors (Sadeghpour 2021)
- rheumatic valve disease
- atrial myxoma
- degenerative valvular disease
- fibroelastoma
- cholesterol embolism syndrome (Ibrahim 2022)
- endomyocarditis eosinophilica:
- Churg- Strauss syndrome
- drug-induced hypersensitivity reaction
- tropical endomyocardial fibrosis (Mubarik 2022).
- E. rheumatica (verrucosa):
- valve destruction
- Heart failure (Jung 2021)
- E. Libman- Sacks: The fibrinous lesions of the affected valve may lead to:
- embolism
- infection
- Very rarely regurgitation of the valve (Kasper 2015).
- pleurisy
- pericarditis (Herold 2022)
- Endomyocarditis eosinophilica:
- Involvement of the myocardium (Herold 2022).
- thromboembolism
- Heart failure (Salih 2021)
- myocardial ischemia
- mitral valve regurgitation
- Aortic valve stenosis (Mubarik 2022).
In all manifestations of abacterial endocarditis, the treatment of the underlying disease is paramount.
These include glucocorticosteroids in SLE or hypereosinophilia and tyrosine kinase inhibitors such as imatinib (trade name Gleevec) in myocardial involvement or hypereosinophilia (Herold 2022).
Curative anticoagulation is often required (LeBot 2018).
- E. rheumatica (verrucosa):
- Penicillin, dosage recommendation: 1 mega penicillin / d for at least 10 days, then p. o. e. g. with Baycillin 3 x 400,000 I. E. / d (Buchborn 2013).
- non-steroidal anti-inflammatory drugs
- Corticosteroids (Buchta 2004), dosage recommendation: 50 mg / d prednisone, weekly reduction of the dose by 10 mg, longer maintenance dose of 20 mg / d. Duration of treatment: at least 6 weeks (Buchborn 2013).
In a 2021 study, Roldan et al. showed that combined anti-inflammatory and antithrombotic therapy can sometimes avoid the need for high-risk valve surgery (Sadeghpour 2021).
- Endomyocarditis eosinophilica:
- Treatment of the underlying disease.
- Anticoagulants (Buchta 2004).
The indication for cardiac surgery has not been well defined to date. However, available data suggest that optimal treatment of the underlying disease is of paramount importance prior to surgery (LeBot 2018).
- E. rheumatica (verrucosa):
The prognosis depends on the valve damage resulting from the disease (Reinhardt 2004).
- E. Libman- Sacks:
Based on clinical observations, the overall prognosis is considered poor because recurrent thromboembolic events, cognitive impairment, and death often occur. However, further studies are needed in this regard for prognostic assessment (Ibrahim 2022).
- Endomyocarditis eosinophilica:
Due to the rarity of the disease, a definite mortality has not yet been defined. Steroid responders have a good prognosis, non-steroid responders a poor prognosis (Mubarik 2022).