These American Heart Association recommendations (free online availability) update the 2005 version and continue to incorporate an evidence-based scoring system for all recommendations.
Recommendations on diagnosis and on use of echocardiography remain essentially unchanged. Additional information is provided on the therapeutic principles of antimicrobial treatment, including treatment duration and recommendations for specific pathogens.
Note that in Australia, Therapeutic Guidelines: Antibiotic remains the central guideline for IE management. The AHA 2015 guidelines mostly align with TG:A (see below for comparison) but also provide much more extensive consideration of finer points of investigation and management.
- Gentamicin for treatment of staphylococcal native valve IE has been removed
- Daptomycin added as alternative agent for methicillin-susceptible or resistant staphylococcal IE
- Staphylococcal IE with concurrent brain abscess considered
- Enterococcal IE : alternative double betalactam therapy with ampicillin and high-dose ceftriaxone regimen included
- Detailed discussion of surgical management, considering timing of interventions, valve surgery for right-sided IE, and surgery in patients with recent stroke or subclinical cerebral emboli
- Follow-up after treatment and dental management of IE patients specified
Our Infectious Diseases registrar , Dr Carly Hughes carefully analysed the new guidelines against the Australian TG: Antibiotic. Discrepancies included (not exhaustive):
- For ‘Relatively Penicillin-Resistant VGS and S . gallolyticus (bovis) (MIC >0.12–<0.5 μg/mL)’ – single dose rather than tds dosed gentamicin (Class IIa; Level of Evidence B)
- For ‘Relatively Penicillin-Resistant VGS and S gallolyticus (bovis) (MIC >0.12–<0.5 μg/mL)’ If the isolate is ceftriaxone susceptible, then ceftriaxone alone may be considered (Class IIb; Level of Evidence C)
- For Left sided IE caused by S. aureus – IE caused by staphylococci that are penicillin susceptible should be treated with anti-staphylococcal β-lactam antibiotics rather than aqueous crystalline penicillin G because clinical laboratories are not able to detect penicillin susceptibility (Class I; Level of Evidence B) [However the ability to reliably detect penicillin susceptibility using the CLSI standard is poor whereas labs that use the EUCAST standard do not have this problem]
- Six weeks of nafcillin (or equivalent antistaphylococcal penicillin) is recommended for uncomplicated left-sided NVE caused by MSSA (as opposed to 4 weeks in TG); at least 6 weeks of nafcillin (or equivalent antistaphylococcal penicillin) is recommended for complicated left sided NVE caused by this organism (Class I; Level of Evidence C)
- Daptomycin may be a reasonable alternative to vancomycin for treatment of left-sided IE resulting from MRSA (Class IIb; Level of Evidence B)
- High level gentamicin-susceptible enterococci – therapy that includes either ampicillin or aqueous crystalline penicillin G plus gentamicin or ampicillin plus ceftriaxone is reasonable (Class IIa; Level of Evidence B)
- Penicillin susceptible, high-level gent resistant enterococci – ceftriaxone+ampicillin combination therapy is reasonable (Class IIa; Level of Evidence B). For high level gentamicin-resistant and streptomycin-susceptible Enterococcus species, ampicillin-ceftriaxone combination therapy is reasonable (Class IIa; Level of Evidence B) – as opposed to TG which says ampicillin or benzylpenicillin monotherapy