Oh, so many learning points from today's case! Here are a few...
1. Anticoagulation recommendations after a surgical bioprosthetic mitral or aortic valve (class IIa evidence): Vitamin K antagonist (INR 2-3) for 3-6 months in patients at low risk of bleeding(Reference: 2017 update of the AHA/ACC Guideline for the Management of Patients with Valvular Heart Disease)
2. Microbiology of prosthetic valve endocarditis depends on the time of onset from surgery. Within the first 2 months of surgery, staph aureus was studied to be the most common culprit. From 2-12 months, coag negative staph was the most common pathogen.
3. Culture-negative prosthetic valve endocarditis increases with time since surgery.
4. Rigors and a recent valve repair is endocarditis until proven otherwise. In bacteremia, shaking chills has a positive likelihood ratio of 4.65, and a negative likelihood ratio of 0.24. (Am J Med 2005)
5. In treating infective endocarditis, does one include the synergistic gentamycin for empiric therapy? A Cochrane Review was performed in 2016 to investigate this. It had limited to very low quality evidence and no conclusive differences between antibiotic regimens in terms of cure rates.