SHM Converge Scientific Abstract ePoster Gallery-Mechanical Valve Endocarditis and Dehiscence From Hacek Bacteremia

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This case describes a 36-year-old man with a history of congenital aortic valve stenosis and two prior mechanical aortic valve replacements who presented with two weeks of fever, chills, fatigue, weakness, and malaise. He was initially treated empirically with vancomycin and piperacillin-tazobactam for suspected endocarditis. His ECG showed new conduction abnormalities, including first-degree atrioventricular block and left bundle branch block, raising concern for perivalvular extension. A temporary pacemaker was placed.<br /><br />Transesophageal echocardiography revealed three vegetations on the mechanical aortic valve, the largest measuring 10 x 19 mm, along with extension into the posterior aortic root consistent with abscess and valve dehiscence. Blood cultures grew Aggregatibacter actinomycetemcomitans, a HACEK organism, and antibiotics were narrowed to ceftriaxone. Because of the abscess, prosthetic valve involvement, and dehiscence, he underwent urgent redo surgery with debridement of the abscess, replacement with a 21 mm On-X mechanical valve, and pericardial patch reconstruction of the aortic root. He completed six weeks of IV ceftriaxone and recovered well.<br /><br />The report highlights that HACEK organisms are gram-negative bacteria from normal oropharyngeal flora and are rare causes of infective endocarditis, accounting for about 1–3% of cases. They most often affect patients with structural heart disease or prosthetic valves and may be difficult to diagnose because of their subacute presentation and prior culture challenges. Ceftriaxone for 4–6 weeks is the mainstay of therapy. Surgery is indicated when there is heart failure, large vegetations, perivalvular abscess, or prosthetic valve involvement.

Asset Subtitle

Jerry Fan

Meta Tag

Author List Billy Jones, Corry Sanford, Jerry Fan

Category Clinical Vignettes

Concept HACEK Organisms

Concept Infective Endocarditis

Concept Prosthetic valve endocarditis

Concept Prosthetic Valve

Concept Antimicrobial Therapy

Distinguished Non-Finalist

Presenter Organization Baylor Scott and White - Temple

Presenting Author Jerry Fan

Track Adult

Keywords

infective endocarditis

HACEK organism

Aggregatibacter actinomycetemcomitans

prosthetic aortic valve

aortic root abscess

valve dehiscence

transesophageal echocardiography

ceftriaxone therapy

redo aortic valve replacement

conduction abnormalities

HACEK Organisms

Infective Endocarditis

Prosthetic valve endocarditis

Prosthetic Valve

Antimicrobial Therapy