Noninfectious endocarditis: causes, symptoms, diagnosis, treatment

Noninfectious endocarditis (non-bacterial thromboendocarditis) is a disease accompanied by the formation of a sterile platelet and fibrin clot on the heart valves and adjacent contiguous endocardium in response to trauma, circulating immune complexes, vasculitis or increased coagulation. Symptoms of noninfectious endocarditis include manifestations of systemic arterial embolism. The diagnosis is established based on echocardiography and negative bacteriological blood test. Treatment consists of the appointment of anticoagulants.

[1], [2], [3]

What causes non-infective endocarditis?

Vegetations are caused by physical trauma, not infection. They may be asymptomatic or become a predisposing factor for the occurrence of infective endocarditis, embolism, or the cause of impairment of valve functions.

When inserting catheters through the right heart, damage to the tricuspid valve or pulmonary artery valve is possible, leading to adherence of platelets and fibrin at the site of the injury. In diseases such as SLE, circulating immune complexes can cause the emergence of loose vegetation from platelets and fibrin along the closing areas of the valve flaps (endocarditis Liebman-Saks).

Procedures that require antimicrobial prophylaxis of endocarditis
 

Dental procedures for manipulation in the oral cavity

Medical surgical procedures

Removal of a tooth. Installation of fillings or crowns, treatment of already sealed teeth. Local injection of anesthetic. Periodontal procedures, including surgical treatment, separation, root treatment of the teeth and diagnostic channeling. Prophylactic cleaning of teeth or implants if there is a risk of bleeding. Instrumental treatment of the canal of the root of the tooth or surgical treatment outside the apex of the tooth. Subgingival placement of orthodontic devices, but not braces

Surgical operations on the biliary tract. Rigid bronchoscopy. Cystoscopy. RCPG in biliary obstruction. Dilation of strictures of the esophagus. Surgical intervention on the intestinal mucosa. Operations on the prostate gland. Operations on the mucosa of the respiratory tract. Sclerosing therapy for varicose veins of the esophageal. Tonsillectomy or adenoidectomy. Dilation of the urethra

Recommended prophylaxis of endocarditis during oral manipulations on the teeth and respiratory tract or endoscopic procedures

Route of drug administration	The drug for adults and children	A drug for people with penicillin allergy
Inside (1 hour before the procedure)	Amoxicillin 2 g (50 mg / kg)	Clindamycin 600 mg (20 mg / kg). Cephalexin or cefadroxil 2 g (50 mg / kg). Azithromycin or clarithromycin 500 mg (15 mg / kg)
Parenteral (30 minutes before the procedure)	Ampicillin 2 g (50 mg / kg) IM or IV	Clindamycin 600 mg (20 mg / kg) IV. Cefazolin 1 g (25 mg / kg) IM or IV

Patients with moderate to high risk.

Recommended endocarditis prophylaxis during invasive procedures in the gastrointestinal tract or urinary tract

Degree of risk *	Dosage and Administration	A drug for people with penicillin allergy
Tall	Ampicillin 2 g IM or IV (50 mg / kg) and gentamicin 1.5 mg / kg (1.5 mg / kg) - do not exceed the dose of 120 mg - IV or IM 30 minutes before procedures; ampicillin 1 g (25 mg / kg) IM or IV or amoxicillin 1 g (25 mg / kg) orally 6 hours after the procedure	Vancomycin 1 g (20 mg / kg) IV for at least 1-2 hours and gentamicin 1.5 mg / kg (1.5 mg / kg) - do not exceed the dose of 120 mg - IV or IM 30 min before the procedure
Moderate	Amoxicillin 2 g (50 mg / kg) orally 1 hour before the procedure or ampicillin 2 g (50 mg / kg) IM or IV 1-2 hours before the procedure	Vancomycin 1 g (20 mg / kg) for 1-2 hours, finish 30 minutes before the procedure

* The risk assessment is based on the attendant conditions:

High risk - artificial heart valve (bioprosthetic or allograft), endocarditis in history, blue congenital heart defects, surgically reconstructed systemic pulmonary shunts or anastomoses;

Moderate risk - congenital heart defects, acquired valve insufficiency, hypertrophic cardiomyopathy, mitral valve prolapse with noise or thickened valve flaps.

These lesions usually do not cause significant valve obstruction or regurgitation. Antiphospholipid syndrome (lupus anticoagulant, repeated venous thrombosis, stroke, spontaneous abortion, livedo reticularis aestivalis) can also lead to sterile endocardial vegetations and systemic embolism. Sometimes Wegener's granulomatosis leads to non-infective endocarditis.

Marantic endocarditis. Patients with chronic debilitating diseases, disseminated intravascular coagulation, synthesizing mucin metastatic cancer (lung, stomach or pancreas), chronic infections (such as tuberculosis, pneumonia, osteomyelitis) on the valves can form large thrombotic vegetations and cause extensive embolism in the brain, kidneys , spleen, mesentery, limbs and coronary arteries. These vegetations tend to form on congenitally altered heart valves or valves damaged by rheumatism.

Symptoms of non-infective endocarditis

Vegetation itself does not cause clinical manifestations. Symptoms are a consequence of embolism and depend on the affected organ (brain, kidney, spleen). Sometimes they find a fever and a noise in the heart.

It is necessary to suspect non-infective endocarditis, when a chronic patient develops symptoms suggesting arterial embolism. A series of bacteriological blood tests and echocardiography are conducted. Negative bacteriological tests and detection of valvular vegetation (but not atrial myxoma) confirm the diagnosis. The study of embolic fragments after embolectomy also helps in the diagnosis. Differential diagnosis with infective endocarditis accompanied by a negative blood culture is often difficult, but it is important, since anticoagulants prescribed for non-infective endocarditis are contraindicated in endocarditis infectious etiology.

Prognosis and treatment of noninfectious endocarditis

The prognosis is generally worse because of the severity of the underlying pathology, than due to heart failure. Treatment includes anticoagulant therapy with heparin sodium or warfarin, although there have been no studies evaluating the outcome of such treatment. Treatment of the underlying disease is indicated, if possible.