We present a unique case of recurrent ischemic stroke in a patient with blood culture-negative bacterial endocarditis.

The incidence of infective endocarditis (IE) has steadily increased in the past decade. About 2-7% of IE cases have negative blood cultures, making it difficult to diagnose with worse resulting prognoses. The risk of neurological complications in culture-negative IE, such as stroke, are high and linked to poor clinical outcomes. However, there are limited data on the incidence of stroke as an isolated presenting symptom or on the rate of stroke recurrence in this population.

A 57-year-old woman with a history of diabetes mellitus, hypertension, and coronary artery disease presented with recurrent multi-territorial ischemic strokes. Her initial work-up showed unclear etiology. A transesophageal echocardiogram was obtained and demonstrated a 0.5x1 cm mobile echodensity on the mitral valve, concerning for either thrombus or vegetation. Thrombophilic laboratory results displayed an indeterminate lupus anticoagulant cascade. As the patient lacked infectious symptoms with an extensive negative infectious workup, she was started on anticoagulation due to possible thrombotic source in the setting of thrombophilia. However, the patient suffered another ischemic stroke while fully anticoagulated. With this being her third stroke in a seven-month period, the patient underwent surgical resection of the lesion. At the time of surgery, the mass was noted to appear as an infectious vegetation, and she was treated with broad-spectrum antibiotics for presumed culture-negative endocarditis. The valve culture later grew Staphylococcus epidermidis. Daptomycin was continued and she has had no additional strokes to date.

It is well-established that stroke is a common complication of IE. However, little has been documented about stroke as the presenting symptom in blood culture-negative IE. Therefore, it is important to maintain a high degree of suspicion for indolent infection to pursue additional work-up and prevent any delays in treatment.