Surgical Intervention is Indicated
A patient with infective endocarditis, vegetations, and abscess who has not improved after 2 weeks of antibiotics requires urgent surgical intervention, as abscess formation represents locally uncontrolled infection that is unlikely to respond to antibiotics alone. 1
Primary Indication: Locally Uncontrolled Infection
The presence of an abscess is a clear sign of locally uncontrolled infection and represents a Class I indication for surgery as soon as possible according to the European Society of Cardiology guidelines. 1 The guidelines explicitly state that signs of locally uncontrolled infection include:
- Abscess formation 1
- Increasing vegetation size 1
- False aneurysms 1
- Fistula creation 1
- Persistent fever (typically present) 1
Surgery is recommended as soon as possible when these features are present. 1
Critical Timing Considerations
The 2-week timepoint is particularly significant because:
- The risk of embolic events is highest during the first 2 weeks of antibiotic therapy and decreases substantially thereafter 1, 2
- Benefits of surgery to prevent embolism are greatest during the first 2 weeks when embolic risk peaks 1
- The embolic rate drops from 4.8/1000 patient-days in the first week to 1.7/1000 patient-days in the second week 1
Rare Exception to Immediate Surgery
The guidelines note that only in rare circumstances when there are no other reasons for surgery AND fever is easily controlled with antibiotics, small abscesses can be treated conservatively under close clinical and echocardiographic follow-up. 1 However, given that this patient has "not improved" after 2 weeks, this exception does not apply.
Additional Evaluation Before Surgery
Before proceeding to surgery, ensure:
- Blood cultures have been checked - if they remain positive after 3 days of appropriate antibiotics, this provides additional indication for surgery 1
- Extracardiac abscesses have been excluded (splenic, vertebral, cerebral, renal) as these may explain persistent fever 1
- Antibiotic regimen is appropriate for the identified organism 1
- Repeat echocardiography (preferably TEE) to assess vegetation size, abscess extent, and valve function 1
Mortality Risk Without Surgery
The mortality rate for medically-treated complicated IE with features like abscess formation is substantially higher than the 2-3% reinfection risk of newly implanted valves during active infection. 1 Delaying surgery in the presence of uncontrolled infection carries risk of permanent ventricular dysfunction and should be discouraged. 1
Common Pitfall to Avoid
Do not delay surgery to "complete" a full antibiotic course when signs of locally uncontrolled infection are present. 1 The traditional approach of waiting 7-10 days for persistent fever has been superseded by evidence showing that abscess formation itself mandates urgent intervention. 1