Infective Endocarditis - July 2024 - PDF

Professor Muhammad Saeed Hussein Gomaa Head Of The Internal Medicine Department. O6U Member Of The American College Of Gastroenterology Professor Muhammad Saeed 1 Introduction Professor Muhammad Saeed 2  Infective endocarditis is defined as an infection, usu...

Professor Muhammad Saeed Hussein Gomaa Head Of The Internal Medicine Department. O6U Member Of The American College Of Gastroenterology Professor Muhammad Saeed 1 Introduction Professor Muhammad Saeed 2  Infective endocarditis is defined as an infection, usually bacterial, of the endocardial surface of the heart. Infective endocarditis affects primarily the cardiac valves, although in some cases, the septa between the chambers, the mural endocardium, or cardiovascular implantable electronic devices (e.g., pacemakers) may be involved. Professor Muhammad Saeed 3  Traditionally, infective endocarditis was categorized as “acute” or “subacute,” based on the duration of symptoms before presentation. Typically, acute infective endocarditis was caused by Staphylococcus aureus, and subacute infective endocarditis was caused by viridans group streptococci. A classification that considers the causative organism and the involved valve is much more clinically relevant. Professor Muhammad Saeed 4 Professor Muhammad Saeed 5 Epidemiology Professor Muhammad Saeed 6  Although some patients have no clearly definable risk factor for endocarditis, cardiac conditions that cause turbulent flow at the endocardial surface or across a valve predispose patients to infective endocarditis The most commonly affected valves in descending order of prevalence are the mitral valve only, the aortic valve, the mitral and aortic valves together, the tricuspid valve, mixed right- and left-sided infection, and the pulmonic valve. Professor Muhammad Saeed 7  Mitral valve prolapse is currently the most common underlying cardiac condition in patients with infective endocarditis, a statistic that reflects its prevalence in the general population (4%). In addition, patients with hypertrophic cardiomyopathy are at increased risk of infective endocarditis, particularly in the presence of outflow obstruction. Finally, previous endocarditis is among the highest risk factors for subsequent infective endocarditis cases. Professor Muhammad Saeed 8  Prosthetic cardiac valves represent an important risk factor for infective endocarditis. The incidence of infective endocarditis in injection drug users may be 30 times higher than in the general population and four times higher than in adults with rheumatic heart disease. Professor Muhammad Saeed 9  Health care–associated infective endocarditis arises primarily as a consequence of invasive therapies, including intravenous (IV) catheters, hyperalimentation lines, pacemakers, other cardiovascular implantable electronic devices, and hemodialysis devices. Cardiovascular electronic devices can become infected at the time they are implanted, particularly if patients develop complications, such as a hematoma, at the incision site or need the device to be revised or replaced. Professor Muhammad Saeed 10 Risk Factors For Infective Endocarditis Professor Muhammad Saeed 11  Pathology Professor Muhammad Saeed 12  Experimental models of infective endocarditis have demonstrated that the disease follows a predictable sequence: 1) endocardial damage, 2) aggregation of platelets and fibrin to create a sterile vegetation, 3) transient bacteremia resulting in seeding of the vegetation, 4) microbial proliferation on and invasion of the endocardial surface, and 5) metastatic infection to visceral organs (e.g., kidneys, spleen) and brain. Professor Muhammad Saeed 13 Professor Muhammad Saeed 14 Professor Muhammad Saeed 15 Microbiology Professor Muhammad Saeed 16  About 90% of community-acquired, native valve infective endocarditis is caused by staphylococci, streptococci, or enterococci, which are normal inhabitants of the skin, oropharynx, urogenital, and gastrointestinal tracts, respectively, and which have frequent access to the blood stream. Professor Muhammad Saeed 17  Streptococcal species are the most common cause of community-acquired infective endocarditis in patients with no history of injection drug use or health care contact. In patients with either of these latter epidemiologic risk factors, S. aureus is the predominant cause of infective endocarditis. Professor Muhammad Saeed 18  Because of the emergence of health care contact as the predominant risk factor for blood stream infections, S. aureus is now the most common cause of infective endocarditis in most industrialized regions of the world. Professor Muhammad Saeed 19  Viridans group streptococci are the most common streptococci implicated in native valve endocarditis. This group of organisms, which normally inhabit the oropharynx. Group B streptococci, β-hemolytic organisms that are also normal oropharyngeal and urogenital flora, most frequently cause infective endocarditis in patients with cirrhosis or diabetes mellitus, as well as in injection drug users. Professor Muhammad Saeed 20  S. aureus is the pathogen of primary concern among injection drug users and patients with health care contact. The clinical course of S. aureus endocarditis is typically acute, with a rapid progression over the course of days. Fungal endocarditis is often difficult to diagnose and treat; it is most commonly found in patients with a history of 1) injection drug use, recent 2) cardiac valve surgery, or 3) prolonged use of indwelling vascular catheters, especially those used for total parenteral nutrition. Professor Muhammad Saeed 21 Professor Muhammad Saeed 22 Clinical Features Professor Muhammad Saeed 23 Professor Muhammad Saeed 24 Professor Muhammad Saeed 25 Professor Muhammad Saeed 26 Poor Prognosis Professor Muhammad Saeed 27 Professor Muhammad Saeed 28  Diagnosis Professor Muhammad Saeed 29  Blood culture (golden standard) Laboratory tests Others: CBC-ESR- Diagnosis of infective CRP endocarditis TTE Echocardiography TEE ( more accurate) Professor Muhammad Saeed 30  Prior antibiotic administration may decrease the yield of blood cultures by up to 35%. Accordingly, most “culture-negative” cases of endocarditis occur in patients who have recently received antimicrobial agents Professor Muhammad Saeed 31  When a history of recent antimicrobial treatment is lacking, consideration should be given to fastidious organisms, fungi, and noncultivatable organisms. It is important to notify the microbiology laboratory that endocarditis is suspected because special culture techniques can increase the yield for the HACEK species, nutritionally variant streptococci (Abiotrophia and Granulicatella spp.), Brucella spp., Legionella spp., and some fungi Professor Muhammad Saeed 32  Treatment Professor Muhammad Saeed 33 Professor Muhammad Saeed 34 Professor Muhammad Saeed 35 Prophylaxis Professor Muhammad Saeed 36 Professor Muhammad Saeed 37 Professor Muhammad Saeed 38 Best Wishes Professor Muhammad Saeed 39