Evaluating Treatment Options for Patients With Infective Endocarditis

When Is It the Right Time for Surgery?

Aneil Malhotra; Bernard D Prendergast

Disclosures

Future Cardiol. 2012;8(6):847-861. 

In This Article

Subgroups That Require Further Consideration

Prosthetic Valve Endocarditis

Prosthetic valve endocarditis (PVE) accounts for 10–20% of most series with an overall incidence of 0.1–2.3% per patient-year.[8,91] Cases may be classified as early or late depending on whether infection arises within 1 year of surgery or later. Early surgery is required in approximately 50% of patients and in-hospital mortality approaches 30%.[8,13,87] Furthermore, long-term follow-up is frequently complicated by recurrent infection, hemodynamic complications, need for repeat surgery and death.

The incidence of early-onset PVE has fallen dramatically as a result of improvements in surgical technique, perioperative antibiotic management and operating room sterility. Early infection peaks 2 months following surgery and is most often due to coagulase-negative staphylococci or S. aureus.[8] Surgical treatment results in improved survival at both immediate and long-term follow-up[92] and is best performed early, especially when infection is caused by S. aureus.[93,94] Operations are frequently technically demanding and these procedures are best undertaken by an experienced surgical team (not necessarily the original surgeon). Rates of recurrent PVE are high at 6–15% and further surgery for this indication or dysfunction of the newly implanted prosthesis is required in up to 25% of patients.[95–97]

The microbial spectrum of late PVE mirrors that of native valve disease. Aggressive tissue destruction is less frequent and early antibiotic therapy is able to effect cure in many patients, especially those in whom infection is caused by a sensitive organism when surgery is often unnecessary.[83]

The Elderly

Valvular heart disease is becoming increasingly frequent in the aging population and this group undergo an increasing variety of invasive medical interventions. Patients aged >65 years have a ninefold increased risk of IE[98] and diagnosis may be particularly difficult owing to delayed presentation, subtle clinical signs and frequent use of pragmatic and empirical antibiotic therapy before hospital admission. Overall outcome is poor[99,100] and although comorbidity may complicate decision-making, age alone is not a preclusion to surgery.[101]

Intravenous Drug Users

Intravenous drug users predominate in series of young people and overall incidence of IE in this group is 1–5%/year.[102] The tricuspid valve is infected in over 70% of cases and the majority have no known pre-existing cardiac disease.[103,104] Staphyloccus aureus species predominate, although unusual infections including Pseudomonas aeruginosa, fungi, Bartonella, Salmonella and Listeria may also be encountered, particularly in those who are HIV-positive.[104]

This group of patients present particular management difficulties due to their drug-seeking behavior and poor compliance with treatment. Medical therapy is usually recommended and short-course therapy and oral regimes may be considered in view of difficulties with compliance. The threshold for intervention and choice of surgical approach may vary in individual patients, where recurrence of infection due to continued drug abuse or compliance with anticoagulant therapy present a dilemma[105] (use of a homograft may be considered in these situations). HIV infection is not a contraindication to cardiac surgery and postoperative complications, including mortality, are not increased in this group.[106]

Right-sided Endocarditis

A conservative approach is recommended for the majority of patients with IE affecting the tricuspid and/or pulmonary valve.[107] Recurrent pulmonary emboli are not an indication for surgery, which is only needed if fever persists despite 3 weeks of appropriate antibiotic treatment in the absence of a pulmonary abscess.[25] Surgical options include debridement of the infected area, vegetectomy with either valve preservation or valve repair, or excision of the tricuspid valve with prosthetic valve replacement.[107,108]

Device-related Endocarditis

The incidence of IE related to permanent pacemakers, implantable defibrillators and other intracardiac devices is rising as a consequence of their widespread use.[109] Management is difficult and entire system removal necessary, although advances in percutaneous techniques mean that a cardiac surgeon is usually not required. Eradication of infection is essential before implantation of a new system.

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