Related Experiment Videos
Actinobacillus actinomycetemcomitans prosthetic valve endocarditis
C J Grace1, R E Levitz, H Katz-Pollak
1Division of Infectious Disease, Hartford Hospital, Connecticut.
Abstract:
Actinobacillus actinomycetemcomitans, a fastidious gram-negative bacillus, has been reported as the cause of prosthetic valve endocarditis in 11 patients. Two additional patients are reported and the literature is reviewed. All cases occurred greater than 1 year after implantation of the prosthesis. Six of the 13 patients had had recent dental work or had poor dentition. Three patients had received endocarditis prophylaxis. Ten of 13 were cured with antibiotics alone. Only one patient suffered from congestive heart failure, and only one had documented evidence of major systemic emboli during antimicrobial therapy. Valve replacement was necessary in only two during antimicrobial therapy. A actinomycetemcomitans should be considered as a possible etiologic agent in late prosthetic valve endocarditis, particularly when blood cultures are initially negative. A regimen of a beta-lactam antibiotic in combination with an aminoglycoside is recommended for 4-6 weeks. The excellent in vitro activity of the third-generation cephalosporins and rifampin promise new therapeutic options.
Insights
Actinobacillus actinomycetemcomitans can cause late prosthetic valve endocarditis, especially with negative initial blood cultures. Most patients recover with antibiotics, often following dental procedures.
Area of Science:
- Infectious Diseases
- Cardiology
- Microbiology
Background:
- Prosthetic valve endocarditis (PVE) is a serious complication following cardiac valve replacement surgery.
- Actinobacillus actinomycetemcomitans (Aa) is a gram-negative bacillus rarely implicated in PVE.
Observation:
- This study reports two new cases of Aa PVE and reviews 11 previously documented cases.
- All identified cases occurred more than one year after prosthetic valve implantation.
- Poor dentition or recent dental work was noted in six patients, and three had received endocarditis prophylaxis.
Findings:
- Actinobacillus actinomycetemcomitans is a potential cause of late PVE, particularly when initial blood cultures are negative.
- Ten out of 13 patients achieved cure with antibiotic therapy alone.
- Congestive heart failure and systemic emboli were infrequent complications during antimicrobial treatment.
Implications:
- Aa should be considered in the differential diagnosis of late PVE, especially in patients with dental issues.
- A 4-6 week treatment regimen combining a beta-lactam antibiotic with an aminoglycoside is recommended.
- Emerging therapeutic options include third-generation cephalosporins and rifampin due to their favorable in vitro activity.