Are there prosthetic valves that predispose to infective endocarditis?

From the Guidelines

Yes, prosthetic valves do predispose to infective endocarditis.

Key Points

• Prosthetic valve endocarditis (PVE) accounts for 10-30% of all cases of infective endocarditis (IE) and is associated with high morbidity and mortality 1, 2, 3.
• The risk of PVE is 10-fold higher compared to native heart valves, with an estimated incidence of 0.3-1.2% per patient per year 2.
• Both mechanical and bioprosthetic valves are equally affected by PVE 3.
• The risk of PVE is highest in the first 3-6 months after prosthetic valve implantation, but remains relatively constant thereafter, requiring lifelong antibiotic prophylaxis for certain procedures 4.
• Common causal agents of PVE include coagulase-negative staphylococci, Staphylococcus aureus, Enterococcus sp., and Gram-negative bacilli 2.
• Diagnosis of PVE can be challenging due to the high variance in blood culture negative endocarditis (BCNE), highlighting the need for molecular biological detection methods 2.
• Patients with prosthetic valves are considered at high risk of IE and should be considered for antibiotic prophylaxis when undergoing high-risk procedures 5.

From the Research

Prosthetic Valves and Infective Endocarditis

• Prosthetic valves can predispose patients to infective endocarditis, with bioprosthetic valves potentially having a higher risk compared to mechanical valves 6, 7.
• The risk of endocarditis is independent of the type, location, or age of the prosthetic valve, with approximately half of all patients with prosthetic valves who develop Staphylococcus aureus bacteremia having definite endocarditis 8.
• Biological valve prostheses are associated with a higher rate of re-intervention for prosthetic valve endocarditis compared to mechanical prostheses 7.
• Mechanical valve prostheses may be associated with a decreased risk of attaining a composite outcome of all-cause mortality, ischemic stroke, hemorrhagic stroke, and re-endocarditis in patients with infective endocarditis presenting with stroke 9.

Types of Prosthetic Valves and Endocarditis Risk

• Bioprosthetic valves: higher risk of infective endocarditis compared to mechanical valves 6, 7.
• Mechanical valves: potentially lower risk of infective endocarditis and re-intervention for prosthetic valve endocarditis compared to bioprosthetic valves 7, 9.

Predictors of Mortality and Re-Intervention

• Early prosthetic valve endocarditis, comorbidity, severe heart failure, and new prosthetic dehiscence are predictors of mortality 10.
• Younger age, male sex, higher creatinine, and biological valve prosthesis are associated with re-intervention for prosthetic valve endocarditis 7.