From the Guidelines
Infective endocarditis requires prompt administration of appropriate antibiotics and early surgical intervention in approximately half of the patients to prevent complications such as heart failure and embolic events. The choice of antibiotics depends on the causative organism, with penicillin G and gentamicin commonly used for streptococcal endocarditis, and nafcillin or oxacillin preferred for staphylococcal infections, with vancomycin used for methicillin-resistant strains or penicillin-allergic patients 1. Blood cultures should be obtained before starting antibiotics to identify the causative organism.
Key Considerations
- Surgical intervention is necessary for complications like heart failure, valve dysfunction, large vegetations, or persistent infection despite antibiotics 1.
- Early consultation with a cardiac surgeon is recommended to determine the best therapeutic approach, and identification of patients requiring early surgery is frequently difficult and is an important objective of the ‘Heart Team’ 1.
- The timing of surgical intervention remains a point of considerable discussion and debate, particularly in patients with preexisting neurological complications, but recent data suggest that the risk of neurological exacerbation may be lower than previously believed 2.
- Individualized clinical assessment is of major importance for decision making, and a functioning endocarditis team, including cardiac surgeons, cardiologists, infectious diseases specialists, neurologists, neurosurgeons, and interventional neuroradiologists, is essential for optimal patient care 2.
Prevention and Management
- Prophylactic antibiotics before dental procedures are recommended for high-risk patients with prosthetic heart valves, previous endocarditis, certain congenital heart defects, or heart transplants with valve problems.
- Regular dental care and prompt treatment of infections elsewhere in the body are important preventive measures.
- The infection develops when bacteria enter the bloodstream and attach to damaged heart valves or abnormal cardiac tissue, forming vegetations that can lead to valve destruction, heart failure, or embolic events.
Treatment Approach
- Treatment requires a multidisciplinary approach, including medical and surgical therapy, and management of associated complications.
- The recommendations outlined in the guidelines should assist physicians in all aspects of patient care, but clinical variability and complexity in infective endocarditis dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management 3.
From the Research
Definition and Treatment of Infective Endocarditis
- Infective endocarditis is a microbial infection of the endocardial surface of the heart, with antibiotics being the cornerstone of treatment 4, 5, 6, 7, 8.
- The use of antibiotics is not standardized due to differences in presentation, populations affected, and the variety of micro-organisms responsible 4, 5.
Antibiotic Regimens
- Different antibiotic regimens have been compared in various studies, including quinolone plus standard treatment, daptomycin versus low-dose gentamicin plus an anti-staphylococcal penicillin, and ceftriaxone plus gentamicin versus ceftriaxone alone 4, 5.
- The results of these studies have shown uncertain effects on all-cause mortality, cure rates, and adverse events, with low to very low-quality evidence 4, 5.
- Recent data have reinforced the role of anti-staphylococcal penicillins for methicillin-susceptible isolates and vancomycin for methicillin-resistant isolates in the treatment of staphylococcal endocarditis 6.
Treatment Duration and Oral Switch
- The optimal duration of antibacterial treatment is 4 weeks for most native valve endocarditis and 6 weeks for prosthetic-valve endocarditis 6.
- The oral switch is safe in patients stabilized after the initial intravenous course 6.
Diagnosis and Management
- The diagnosis of infective endocarditis may be difficult to establish and requires a combination of clinical, microbiological, and echocardiography results, as codified in the modified Duke criteria 7.
- Once diagnosed, infective endocarditis is best managed by a multidisciplinary team with expertise in infectious diseases, cardiology, and cardiac surgery 7.