Timing of Repeat Echocardiography After Starting Antibiotics for Infective Endocarditis
Repeat echocardiography should be performed within 5-7 days if initial imaging is negative but clinical suspicion remains high, or immediately if new complications develop during treatment. 1
Immediate Repeat Imaging (Emergent)
Obtain repeat TTE/TEE immediately if any of the following complications develop during antibiotic therapy: 1
- New or changing cardiac murmur
- Unexplained progression of heart failure symptoms
- New atrioventricular block or arrhythmia
- Embolic events
- Persistent fever despite appropriate antibiotics
- New abscess formation suspected
These findings indicate potential treatment failure, progression of infection, or development of perivalvular complications that may require urgent surgical intervention. 1
Scheduled Repeat Imaging (5-7 Days)
Repeat TEE within 5-7 days after an initially negative study when: 1
- Clinical suspicion of IE remains high despite negative initial imaging
- Patient has prosthetic valve or intracardiac device (higher false-negative rate)
- Staphylococcus aureus bacteremia (may require even earlier repeat imaging due to rapid progression) 1
The rationale is that vegetations may be too small to detect initially, or perivalvular abscesses may appear only as nonspecific thickening that becomes recognizable as it expands and cavitates over several days. 1
Routine Surveillance During Uncomplicated Treatment
Repeat TTE/TEE should be considered during follow-up of uncomplicated IE to detect silent complications and monitor vegetation size, though the exact timing depends on: 1
- Initial echocardiographic findings (large vegetations, severe regurgitation, abscess)
- Type of microorganism (S. aureus requires closer monitoring)
- Initial response to therapy
- Presence of high-risk features (prosthetic valve, perivalvular extension)
For patients with initially positive TTE who are at high risk for complications (including perivalvular extension), TEE should be obtained as soon as possible even if TTE was diagnostic. 1
At Completion of Therapy
TTE is recommended at completion of antibiotic therapy to establish a new baseline for valve morphology, ventricular function, and valve function for future comparison. 1 TEE may be needed for complex anatomy or prosthetic valves. 1
Important Clinical Caveats
TEE is superior to TTE for detecting vegetations (96% vs 70% sensitivity for native valves; 92% vs 50% for prosthetic valves) and is essential for identifying perivalvular complications. 1, 2
Early TEE may miss incipient abscesses that appear only as nonspecific perivalvular thickening, which is why repeat imaging at 5-7 days is critical when suspicion persists. 1
An increase in vegetation size despite appropriate antibiotics has serious implications and is associated with increased risk of complications and need for surgery. 1
Contemporary TEE technology (3D imaging, higher frame rates) has improved diagnostic performance, particularly for prosthetic valve endocarditis, with sensitivity increasing from 71% to 94% in recent years. 3
Male gender and presence of prosthetic valve are associated with higher likelihood of requiring repeat TEE during treatment. 4
In a contemporary cohort, 44.7% of IE patients underwent repeat TEE, with 17.4% of repeat studies being critical for diagnosis and 23.9% supporting surgical intervention decisions. 4