How soon should patients with infective endocarditis be referred for valve surgery?

Right-sided infective endocarditis

Right-sided infective endocarditis has a more favorable prognosis than left-sided infective endocarditis and usually responds well to medical therapy.¹¹

Nevertheless, surgery for right-sided infective endocarditis should be expedited in patients with right heart failure secondary to severe tricuspid regurgitation with poor response to medical therapy or in the case of large tricuspid valve vegetations.¹² Likewise, recurrent septic pulmonary emboli can be encountered in the setting of right-sided infective endocarditis and are an indication for early surgery.^4,12

Since many patients with right-sided infective endocarditis acquire the infection by intravenous drug use, there is often a reluctance to recommend surgery, given the risk of prosthetic valve infection if they continue to use intravenous drugs.^4,12 One study showed that the risk of death or reoperation between 3 and 6 months after surgery for infective endocarditis was 10 times higher in intravenous drug users. Yet their survival after surgery beyond this period was similar to that of patients with endocarditis who did not inject drugs.¹³ Therefore, the AATS guidelines recommend applying normal indications for surgery to those patients, with emphasis on the need for strict follow-up aimed at addiction treatment.²

Prevention of embolic events

Neurologic embolic events are a frequent complication of infective endocarditis, with the highest risk during the first few days after antibiotics are started. However, this risk decreases significantly after 2 weeks.¹⁴

The timing of surgery largely depends on whether the patient has had previous neurologic embolic events and on the size and mobility of the vegetation. The current guidelines recommend early surgery for recurrent emboli and persistent or enlarging vegetations despite appropriate antibiotic therapy, or in case of large vegetations (> 10 mm) on a native valve even in the absence of embolic events.⁴

A randomized trial by Kang et al¹⁵ demonstrated that, compared with conventional care, early surgery (within 48 hours of diagnosis) in patients with native valve endocarditis with large vegetations (> 10 mm) and severe valve dysfunction was associated with a significant reduction in the risk of death and embolic events.

Timing of surgery after a neurologic complication

Determining the right time for surgery is challenging in patients with infective endocarditis who have had neurologic complications, given the risk of hemorrhagic conversion of existing stroke with anticoagulation or exacerbation of cerebral ischemia in case of intraoperative hypotension. The decision should take into account the severity of cardiac decompensation, weighed against the severity of neurologic symptoms.

In general, surgery should be postponed for at least 4 weeks after intracerebral hemorrhage. However, it should be expedited in the event of silent cerebral embolism or transient ischemic attack, or in patients with infective endocarditis with stroke who have other indications for early surgery, as long as cerebral hemorrhage has been excluded by appropriate imaging.⁴

Early surgery for prosthetic valve endocarditis

The timing of surgery for prosthetic valve endocarditis follows the same general principles as for native valve endocarditis.^2–4,12

One study showed that early surgery for prosthetic valve endocarditis was not associated with lower in-hospital and 1-year mortality rates compared with medical therapy.¹⁶ On the other hand, a subgroup analysis demonstrated surgery to be significantly beneficial in those with the strongest indications for surgery, including severe valve regurgitation, heart failure, paravalvular abscess, fistula, or prosthetic valve dehiscence.

The decision to proceed with surgery in prosthetic valve endocarditis should be weighed carefully, taking into consideration the patient’s overall clinical condition and estimated surgical risk.¹⁶

COLLABORATION IS HELPFUL

Early surgery is indicated for infective endocarditis patients presenting with:

• Refractory heart failure symptoms
• Persistent infection
• Large vegetations with a high risk of embolism.

Expeditious and successful treatment entails multidisciplinary collaboration among experts in cardiology and infectious diseases with access to cardiac surgery input early in the evaluation.