Endocarditis is a life-threatening infection of the heart’s endocardial lining, most often involving the heart valves. While medical management with prolonged antibiotics is the first-line therapy, some patients require urgent or early surgical intervention to prevent complications or death. Recognizing when to operate is critical, as delays can lead to irreversible cardiac damage, systemic embolization, or uncontrolled sepsis.
Cardiologists and cardiothoracic surgeons often rely on well-established guidelines such as those from the European Society of Cardiology (ESC) and the American Heart Association (AHA) to determine surgical timing. One simple, high-yield way to recall the core surgical indications is the mnemonic PHASE.
Mnemonic: PHASE
The mnemonic PHASE represents the five main categories of surgical indications in endocarditis:
| Letter | Indication | Key Clinical Context |
|---|---|---|
| P | Prosthetic | Prosthetic valve endocarditis with complications or early infection |
| H | Heart failure | Acute severe valvular dysfunction causing refractory heart failure |
| A | Abscesses | Perivalvular abscess, fistula, or pseudoaneurysm |
| S | Sepsis / Size | Uncontrolled infection or large vegetations |
| E | Embolization | Recurrent emboli or high embolic risk |
P – Prosthetic Valve Endocarditis
Definition & Risk
Prosthetic valve endocarditis (PVE) is an infection involving mechanical or bioprosthetic heart valves. It has higher morbidity and mortality compared to native valve endocarditis because:
- Biofilm formation on prosthetic material is resistant to antibiotics.
- Prosthetic valve dysfunction can rapidly destabilize hemodynamics.
Surgical Indications in PVE
Surgery is indicated in:
- Early PVE (< 60 days post-surgery) – often due to Staphylococcus aureus, Candida, or multidrug-resistant bacteria.
- Prosthetic dehiscence (valve becomes loose).
- Severe prosthetic regurgitation or obstruction.
- Evidence of paravalvular complications – abscesses, fistulae.
Evidence
ESC guidelines recommend urgent surgery for early PVE with heart failure, uncontrolled infection, or large vegetations (>10 mm) associated with embolism.
H – Heart Failure
Pathophysiology
Infective endocarditis can cause acute severe valve regurgitation due to:
- Leaflet perforation
- Chordae tendineae rupture
- Papillary muscle dysfunction
- Prosthetic valve dysfunction
This results in acute pulmonary edema or cardiogenic shock.
Surgical Timing
- Emergency (<24 h): Acute severe regurgitation with refractory pulmonary edema or shock.
- Urgent (<7 days): Severe regurgitation causing NYHA Class III–IV symptoms despite optimal therapy.
Key Point: Heart failure is the strongest predictor of mortality in infective endocarditis and the most common reason for surgical intervention.
A – Abscesses
What They Are
A cardiac abscess is a localized collection of pus within the heart tissue, often in the perivalvular area. They are most common in aortic valve endocarditis.
Why Surgery is Needed
- Antibiotics penetrate poorly into abscess cavities.
- They can cause conduction abnormalities (e.g., AV block).
- Risk of fistula formation between cardiac chambers or vessels.
Surgical Goals
- Drain abscess cavity.
- Repair or replace affected valve.
- Debride infected tissue to prevent recurrence.
S – Sepsis (Uncontrolled) / Size of Vegetation
Uncontrolled Sepsis
If fever and positive blood cultures persist >7–10 days despite appropriate antibiotics, surgery is considered to:
- Remove infected tissue.
- Eliminate the source of bacteremia.
- Prevent septic shock.
Size of Vegetation
Large vegetations (>10 mm) are associated with:
- Higher risk of systemic embolization.
- Poor response to antibiotics.
- Higher mortality rates.
ESC Surgical Recommendation:
- Vegetation >10 mm + prior embolic event → early surgery.
- Vegetation >15 mm even without embolism → consider surgery.
E – Embolization
Mechanism
Vegetations (infected masses on valves) can break off, traveling to:
- Brain → stroke
- Lungs → pulmonary embolism (in right-sided IE)
- Spleen → splenic infarcts
- Kidneys → renal infarcts
Surgical Indication
- Recurrent emboli despite adequate antibiotics.
- Single embolic event in presence of large, mobile vegetation.
Timing of Surgery in Endocarditis
The timing depends on urgency:
| Timing | Example Indications |
|---|---|
| Emergency (<24 h) | Acute severe regurgitation with refractory HF, prosthetic valve dehiscence |
| Urgent (within a few days) | Large vegetation with embolic event, uncontrolled infection |
| Elective | Stable patient with complications but no hemodynamic compromise |
Risks of Surgery in Endocarditis
- Perioperative mortality (5–15%)
- Stroke during cardiopulmonary bypass
- Reinfection of prosthetic material
- Heart block requiring pacemaker
However, in properly selected patients, surgery improves survival and quality of life.
Quick Reference Table – PHASE Mnemonic in Surgical Indications
| Mnemonic Letter | Indication | Examples |
|---|---|---|
| P | Prosthetic | Early PVE, valve dehiscence, paravalvular leak |
| H | Heart failure | Acute severe AR/MR with pulmonary edema |
| A | Abscesses | Perivalvular abscess, fistula |
| S | Sepsis / Size | Persistent bacteremia, vegetation >10–15 mm |
| E | Embolization | Recurrent emboli, large mobile vegetation |
Frequently Asked Questions (FAQ)
1. Can all cases of endocarditis be managed with surgery?
No. Many patients respond well to antibiotics alone. Surgery is reserved for those with PHASE criteria, high complication risk, or poor antibiotic response.
2. Why is prosthetic valve endocarditis more dangerous?
Because bacteria adhere strongly to prosthetic material, form biofilms, and resist antibiotics, making eradication difficult without surgery.
3. What is the most urgent indication for surgery in endocarditis?
Acute severe valve regurgitation causing refractory heart failure.
4. Is there a role for surgery in right-sided endocarditis?
Yes, in cases of large vegetations, recurrent pulmonary emboli, or persistent sepsis despite antibiotics.
5. How soon should surgery be performed after a stroke from embolization?
If the stroke is ischemic and non-hemorrhagic, surgery can be considered within a few days if urgent. For hemorrhagic stroke, surgery is usually delayed unless life-threatening cardiac indications exist.
