Infective endocarditis: what has changed in the last decade?

Abstract

Revista HUPE, Rio de Janeiro, 2013;12(Supl 1):100-109

doi:10.12957/rhupe.2013.7088

Infective endocarditis (IE) remains a disease with high morbidity and mortality despite advances in clinical diagnosis, in the development of new antibiotics and in improvement in surgical techniques. Standardizing clinical and laboratory diagnostic criteria and establishing treatment protocols are strategies that improve disease impact. An important finding in the pathogenesis of IE is endothelial lesion caused by turbulent blood flow, may it be that generated by a defective valve  (rheumatic valve, bicuspid aortic valve, malfunctioning valve prosthesis),  by a congenital defect (interventricular septum,  hypertrophic cardiomyopathy,  aortic coarctation).  The presence of intracardiac devices, such as pacemakers or implanted defibrillators, may serve as surfaces that promote  adherence of thrombi and development of vegetations. Valves most often affected in IE are the mitral valve (40%) and the aortic valve (34%), followed by concomitant affection of both.  Tricuspid  and/or  pulmonary valve IE occurs more often in intravenous drug users and as a complication of  deep venous catheter blood stream infection. The pulmonary valve is seldom affected. Vegetations are avascular structures, making treatment difficult due to the low  concentrations  that reach microorganisms. This demands prolonged administration and  a high serum concentration of antibiotics, administered parenterally.Transthoracic echocardiograms (TTE) and transesophageal echocardiograms (TEE) are extremely important  for diagnosis, prognosis,  assessment of complications  and for patient follow up. In the presence of degenerative valve disease, calcification or prosthetic valves, and intravascular devices, TEE is the method of choice for best evaluation of vegetations. Treatment protocols are proposed for the different clinical presentations of endocarditis, based on the most likely etiological agent or the isolated microorganism, when possible.  These are based on international treatment guidelines, adapted to the Brazilian scenario. Emphasis is placed on the importance of intravascular access for prolonged antibiotic treatment.

Keywords: Endocarditis; Heart valves; Echocardiography; Anti-bacterial agents.