AHA 2026 Scientific Statement: Infective Endocarditis

 AHA 2026 Scientific Statement: Infective Endocarditis

Diagnosis, Antibiotic Therapy, and Management

Take-home messages for bedside and exam use

1. Incidence of IE has risen since the 2015 AHA statement. 

Drivers: injection-drug-use IE, older patients with more comorbidity, and more prosthetic valves and cardiac devices.

2. One-year mortality remains about 40 percent. 

Care is no longer prolonged IV antibiotics plus delayed surgery alone.

3. Use a multidisciplinary Endocarditis Team

(cardiology, infectious diseases, cardiac surgery, imaging, microbiology, pharmacy). 

Team care is linked to better outcomes.

4. Diagnose with the 2023 Duke / ISCVID criteria. 

They add molecular microbiology and multimodality imaging and improve sensitivity versus the 2000 modified Duke criteria.

5. Echo is still first-line imaging (TTE then TEE). 

Repeat within about 1 week if the first study is normal or inconclusive and suspicion remains high.

6. In TAVR-associated IE, TTE and TEE both miss disease. 

Add multimodality imaging, especially 18F-FDG PET/CT.

7. Cardiac CT helps map paravalvular and periprosthetic complications.

8. Molecular tests on blood or resected valve tissue help when cultures are negative or inconclusive.

9. Need for echo in bloodstream infection without known valve disease depends on the organism and the patient's IE risk, not a blanket rule.

10. After the acute IV phase, selected stable patients may finish with oral antibiotics (POET-style) or long-acting lipoglycopeptides (dalbavancin or oritavancin), after bacteremia has cleared and the team agrees.

11. Do not add gentamicin for staphylococcal prosthetic-valve IE. Harm exceeds benefit.

12. Positive culture or molecular tests on the explanted valve do not automatically prolong postoperative antibiotics.

13. Percutaneous mechanical aspiration may be considered for selected high-surgical-risk patients with right-sided IE who fail medical therapy. Trials are still needed.

14. When surgery is indicated, operate early unless there is a major stroke or hemorrhage. Stroke timing needs the full team.

15. End-of-therapy echo establishes a new baseline. Chronic antimicrobial suppression is for selected patients only.

Antibiotic regimen shifts vs 2015 

Duration (2026):

Staphylococci: native valve 4 weeks; prosthetic valve 6 weeks 

(2015 used 6 weeks for all, plus 2 weeks of gentamicin synergy).

Viridans group streptococci / S. gallolyticus: native 4 weeks; prosthetic 6 weeks.

E. faecalis / E. faecium: native 6 weeks; prosthetic 6 weeks 

(was 4 weeks if symptoms less than 3 months).

Staphylococci:

MSSA native: 

nafcillin or oxacillin 12 g/24 h in 6 doses, or 

cefazolin 6 g/24 h in 3 doses. 

Continuation options after more than 10 days IV and cleared bacteremia: 

dalbavancin or oritavancin, or 

oral dicloxacillin / linezolid plus rifampin or fusidic acid (POET-style; fusidic acid is not available in the US).

MSSA prosthetic: 

same beta-lactam PLUS rifampin 900 mg/24 h. 

Delay rifampin until bacteremia has cleared and 5 to 7 days of antibiotics have been given. 

No 2015-style 2-week gentamicin.

MRSA native: 

vancomycin 30 mg/kg/24 h in 2 doses, or 

daptomycin 8-12 mg/kg daily, or 

ceftaroline 600 mg every 8 h, or 

linezolid 600 mg every 12 h.

MRSA prosthetic: 

vancomycin or daptomycin or ceftaroline or linezolid PLUS rifampin. 

Again, no routine gentamicin.

Viridans streptococci / S. gallolyticus :

Penicillin-susceptible (MIC less than 0.12 mg/L): 

penicillin G 24 million units/24 h or 

ceftriaxone 2 g daily. 

Gentamicin is no longer routine for fully susceptible strains.

Unable to take beta-lactams: 

vancomycin or linezolid.

Intermediate or resistant strains:

ceftriaxone plus short gentamicin or vancomycin, as in the table. 

Oral step-down after at least 10 days IV if stable: amoxicillin plus rifampin, or linezolid plus rifampin or moxifloxacin.

Enterococci:

E. faecalis preferred 2026 start: 

Ampicillin 2 g IV every 4 h PLUS ceftriaxone 2 g IV twice daily (ampicillin monotherapy is discussed in the statement for selected cases). This replaces the old ampicillin plus gentamicin default.

If beta-lactam cannot be used: 

vancomycin or linezolid or daptomycin 10-12 mg/kg daily.

Vancomycin-resistant E. faecium: linezolid 600 mg twice daily or daptomycin 10-12 mg/kg daily, often with a beta-lactam. Long-acting lipoglycopeptides are not advised here.

Oral or long-acting continuation :

Only after bacteremia has cleared. 

Oral step-down usually after more than 10 days of IV therapy, in patients who meet POET-style stability criteria, decided by the Endocarditis Team. 

Long-acting lipoglycopeptide: one dose counts as about 2 weeks of therapy; two doses about 6 weeks.

Five lines to remember in viva / rounds

- Team first. Then 2023 Duke / ISCVID, not 2000 modified Duke alone.

- Echo first. PET/CT when the valve is prosthetic or TAVR and echo is inconclusive.

- No gentamicin for staph prosthetic-valve IE.

- E. faecalis: ampicillin plus ceftriaxone, not automatic gentamicin.

- Do not treat a scan of HALT-style findings here: finish selected stable patients with oral or long-acting drugs; operate early unless major stroke or bleed.

NOTE:

This is a teaching summary of the public AHA top-things list.

 It is not a substitute for the full Circulation statement. 

Doses must be checked against the official tables and local susceptibility before prescribing.