# Surgical Management of Infective Endocarditis — AHA 2015

## Indications for Early Surgery — Native Valve Endocarditis

### Class I (Recommended) Indications

Early surgery during initial hospitalization is recommended for NVE in the following scenarios:

1. **Heart failure:** Valve dysfunction (regurgitation or obstruction) resulting in symptoms or signs of heart failure (Class I, Level of Evidence B)
2. **Left-sided IE caused by S. aureus, fungal, or other highly resistant organisms** (e.g., VRE, multidrug-resistant gram-negative bacilli) (Class I, Level of Evidence B)
3. **Complications of IE:**
   - Heart block (Class I, Level of Evidence B)
   - Annular or aortic abscess (Class I, Level of Evidence B)
   - Destructive penetrating lesions (e.g., sinus of Valsalva to right-sided chamber fistula) (Class I, Level of Evidence B)
4. **Persistent infection:** Evidence of persistent infection manifested as persistent bacteremia or fevers lasting **> 5-7 days** after onset of appropriate antimicrobial therapy and after other sources of infection/fever have been excluded (Class I, Level of Evidence B)

### Class IIa (Reasonable) Indications

1. **Recurrent emboli and persistent or enlarging vegetations** despite appropriate antimicrobial therapy (Class IIa, Level of Evidence B)
2. **Mobile vegetations > 10 mm in length** with or without clinical evidence of embolic phenomena (Class IIa, Level of Evidence B)

### Class IIb (May Be Considered) Indications

1. **Mobile vegetations > 10 mm in length** on the anterior (aortic) mitral leaflet, particularly with other relative indications for surgery (Class IIb, Level of Evidence C)

## Indications for Early Surgery — Prosthetic Valve Endocarditis

### Class I (Recommended) Indications

Early surgery is recommended for PVE in:

1. **Heart failure:** Valve dysfunction resulting in symptoms or signs of heart failure (Class I, Level of Evidence B)
2. **Persistent bacteremia or fevers lasting > 5-7 days** after onset of appropriate antimicrobial therapy, and after exclusion of other causes (Class I, Level of Evidence B)
3. **IE complicated by:**
   - Heart block (Class I, Level of Evidence B)
   - Annular or aortic abscess (Class I, Level of Evidence B)
   - Destructive penetrating lesions (Class I, Level of Evidence B)
4. **IE caused by fungi or highly resistant organisms** (Class I, Level of Evidence B)

### Class IIa (Reasonable) Indications for PVE

1. **Recurrent emboli despite appropriate antimicrobial therapy** (Class IIa, Level of Evidence B)
2. **Relapsing PVE** (defined as recurrence of IE after completion of an appropriate course of antimicrobial therapy) (Class IIa, Level of Evidence C)

## Surgical Decision-Making Algorithm

```
Patient with IE requiring potential surgical intervention

Step 1: Is there an emergent (Class I) indication?
  - Heart failure from valve dysfunction? -> Urgent surgery
  - Annular abscess / heart block / destructive lesion? -> Urgent surgery
  - Fungal or highly resistant organism? -> Urgent surgery
  - Persistent bacteremia/fevers > 5-7 days on appropriate therapy? -> Urgent surgery

Step 2: If no emergent indication, is there a Class IIa indication?
  - Recurrent emboli + persistent vegetations? -> Consider surgery
  - Mobile vegetation > 10 mm? -> Consider surgery (weigh embolic risk)

Step 3: Can the patient tolerate surgery?
  - Assess operative mortality risk (age, comorbidities, hemodynamic status)
  - For high surgical risk: medical management with close monitoring
  - Multidisciplinary team (cardiothoracic surgery, cardiology, infectious disease) should make the final decision
```

## Timing of Surgery

### Emergent Surgery (Same Day)

- Acute aortic regurgitation or mitral regurgitation with refractory pulmonary edema or cardiogenic shock

### Urgent Surgery (Within Days)

- Heart failure that can be medically managed short-term
- Paravalvular abscess or fistula
- Persistent sepsis despite appropriate therapy for > 5-7 days
- Large mobile vegetations with embolic events

### Elective Surgery (1-2 Weeks)

- Large vegetations without embolic events (after initial antibiotic stabilization)
- Progressive paravalvular prosthetic regurgitation without heart failure

## Surgery in the Setting of Neurological Complications

### Ischemic Stroke

- Cardiac surgery is **not contraindicated** after an ischemic embolic stroke if the stroke is small or moderate and there is no hemorrhagic transformation (Class IIa, Level of Evidence B)
- For patients with a **major ischemic stroke**, it is reasonable to delay cardiac surgery for **at least 4 weeks** unless urgent indications exist (e.g., refractory heart failure, uncontrolled infection)
- Preoperative neurological imaging (CT or MRI) should be performed in **all patients with IE** being considered for surgery (Class I, Level of Evidence B)

### Hemorrhagic Stroke

- In patients with a hemorrhagic stroke or hemorrhagic transformation, it is recommended to delay surgery for **at least 4 weeks** when feasible (Class IIa, Level of Evidence B)
- Vascular imaging should be performed to rule out **ruptured mycotic aneurysm** as the cause of hemorrhage

### Mycotic Aneurysm

- Mycotic aneurysms are found in approximately 2-4% of IE patients
- If a mycotic aneurysm is identified, it should be treated (endovascular coiling or surgical clipping) **before cardiac surgery** when possible

## Operative Considerations

### Valve Repair vs. Replacement

- **Valve repair** is preferred over replacement when feasible, particularly for mitral valve IE (Class IIa, Level of Evidence B)
- Valve repair preserves native tissue, avoids long-term anticoagulation, and has lower operative mortality in experienced centers
- **Valve replacement** is necessary when tissue destruction is extensive, when repair is technically not feasible, or for prosthetic valve IE
- Choice of prosthesis (mechanical vs. bioprosthetic) depends on patient factors (age, anticoagulation tolerance, expected durability)

### Intraoperative Cultures

- Valve tissue excised at surgery should be sent for **culture and histopathology** (Class I, Level of Evidence B)
- Positive valve cultures guide postoperative antibiotic duration

### Postoperative Antibiotic Duration

- If intraoperative valve cultures are **negative**: complete the initially planned preoperative course (count from first negative blood culture)
- If intraoperative valve cultures are **positive**: a full postoperative course of antibiotics is recommended (typically 6 weeks from the date of surgery for most organisms)

## Special Populations

### Injection Drug Users (IDU) with Right-Sided IE

- Right-sided (tricuspid valve) IE in IDU caused by MSSA has a favorable prognosis with medical therapy alone (cure rates > 90%)
- Surgery is indicated for right-sided IE when:
  - Failure to respond to appropriate antimicrobial therapy
  - Right-sided heart failure secondary to severe tricuspid regurgitation with poor response to diuretics
  - Tricuspid vegetations > 20 mm with recurrent pulmonary emboli
- Valve repair is preferred; tricuspid valvectomy without replacement may be considered in refractory cases

### Cardiac Device-Related IE

- Complete device and lead removal is recommended for patients with definite cardiac device-related IE (pacemaker, ICD) (Class I, Level of Evidence B)
- Percutaneous lead extraction is preferred when leads have been implanted < 2 years and there is no large vegetation
- Surgical extraction is indicated for large vegetations (> 2 cm) or when percutaneous extraction fails

## Limitations

- Surgical decision-making relies on observational studies and expert consensus; no large randomized controlled trials compare early surgery with medical therapy for most indications
- The optimal timing of surgery after neurological complications remains an area of clinical judgment rather than firm evidence-based thresholds
- Risk stratification for operative mortality in IE patients is complex and multifactorial; no single scoring system is validated for this purpose
