Treatment of streptococcal infective endocarditis

Area of Science:

• Infectious Diseases
• Cardiology
• Pharmacology

Background:

• Infective endocarditis (IE) poses significant mortality and morbidity risks.
• Treatment strategies for streptococcal and enterococcal IE vary based on causative agents and patient factors.
• Optimizing antibiotic regimens balances efficacy with toxicity and cost-effectiveness.

Purpose of the Study:

• To evaluate the efficacy and safety of different antibiotic regimens for infective endocarditis.
• To compare treatment outcomes for penicillin-sensitive streptococcal IE versus enterococcal IE.
• To identify risk factors influencing relapse and mortality in IE patients.

Main Methods:

• Retrospective analysis of 142 patients with penicillin-sensitive streptococcal IE treated with penicillin G alone or in combination with streptomycin.
• Analysis of patients with enterococcal IE treated with penicillin G plus streptomycin or gentamicin.
• Assessment of cure rates, relapse rates, mortality, and adverse events (vestibular toxicity, nephrotoxicity).

Main Results:

• Penicillin-sensitive streptococcal IE achieved >98% cure rates with four-week penicillin G or two-week penicillin G/streptomycin regimens.
• Two-week regimens for streptococcal IE were cost-effective with low relapse (0.7%) and vestibular toxicity (3%).
• Enterococcal IE patients with symptoms >3 months or mitral valve involvement had higher relapse (44%) and mortality (25%) rates; duration of symptoms and valve affected were significant predictors.

Conclusions:

• Short-term (2-week) penicillin and streptomycin therapy is effective and cost-efficient for select streptococcal endocarditis cases.
• Enterococcal endocarditis patients with prolonged symptoms or mitral valve involvement require extended therapy (≥6 weeks) with penicillin and an aminoglycoside.
• Gentamicin nephrotoxicity is dose-dependent, necessitating careful dosing to minimize adverse effects.