Case Report: Infective Endocarditis in Child with Native Valve Abnormality Complicated by Septic Embolus

Introduction: Infective endocarditis (IE) is most commonly seen in patients with repaired or unrepaired congenital heart disease. Native valvular abnormalities are currently not an indication for antibiotic prophylaxis by the American Heart Association (AHA). We report a case of a patient with a unicuspid unicommissural aortic valve that was diagnosed with IE and calf pain secondary to septic embolus.

Case Description: This patient is an 8-year-old female with a history of unicuspid unicommissural aortic valve (Figure 1) who was diagnosed with IE two weeks prior to presentation with a positive blood culture for Granulicatella adiacens and an echocardiogram demonstrating a stable vegetation on the aortic valve (Figure 2). Of note, the patient sustained oral trauma with teeth loosening several months before. A PICC line was placed, and she was eventually discharged on a prolonged antibiotic course of vancomycin.

The patient presented to our emergency department with right lower extremity pain and refusal to walk. She was afebrile with normal vital signs and was found to have a murmur on exam, pain to palpation of the right popliteal fossa, and 2+ pulses throughout. Labs were significant for CRP 96 and a D-Dimer 1.06. MRI of the right lower extremity demonstrated deep posterior compartment myositis and fasciitis with questionable thrombus. CT Angiogram of the right lower extremity showed right posterior tibial artery occlusion and concern for right peroneal artery occlusion. Repeat echocardiogram now showed a fibrinous strand in the left ventricular outflow tract and worsened moderate insufficiency of the aortic valve. The patient was discharged on a four-week course of Lovenox for anticoagulation and continued vancomycin for six weeks.

Discussion: This patient with a unicommissural unicuspid valve was diagnosed with IE and later developed a septic embolus to the right leg. The microorganism isolated, Granulicatella adiacens, is a nutritionally variant streptococcal oral anaerobe that is not a very common cause of IE in children. It usually presents in a subacute manner, as was seen in this case. The inciting event that introduced this bacterium was likely dental trauma that occurred several months prior.

This case is interesting in that native valve abnormalities are not considered congenital heart lesions that require antibiotic prophylaxis, which may suggest that there should be exceptions to the current guidelines. History of significant dental or oral trauma should also be recognized in a patient that is at increased risk for IE.

Conclusion: Native valve abnormalities are currently not indications for antibiotic prophylaxis for infective endocarditis, however this case report suggests that these patients may also be at risk. In addition, history of oral trauma should be identified in patients at increased risk for IE.