Case report
A 51-year-old healthy male patient with no relevant medical history was admitted to the emergency room with a one-week history of fever having a mild response to paracetamol, headaches, myalgia and neck stiffness. He denied coughing, dyspnea or chest pain. During physical examination, his heart rate was 145 bpm and blood pressure was 90/60 mmHg. Cardiopulmonary auscultation was rhythmic and showed no abnormalities. Laboratory results on admission showed a leukocyte count of 22,860/μL with neutrophilia (84.9%) and thrombocytopenia (49,000/μL). Acute kidney injury was also shown by a creatinine of 1.4 mg/dL and hyponatremia (126 mmol/L). Bilirrubin was 1.4 mg/dL. Arterial blood gases showed hypoxemia and hypocapnia with secondary respiratory alkalosis. Acute-phase reactants were elevated with a C-reactive protein of 23.4 mg/dL (0.0 – 0.5) and a procalcitonin of 5.26 μg/L (0.00 – 0.50). The chest X-Ray showed no significant findings. Blood, urine cultures and a nasal swab were drawn, which were all positive for Methicillin-sensitive Staphylococcus aureus (MSSA).
The patient was directly admitted into the intensive care unit with the diagnosis of septic shock. Broad-spectrum antibiotic therapy was started with Meropenem and Vancomycin. Blood cultures were drawn again the next day, being still positive for MSSA. The patient required vasoactive drugs for 48 hours. After 72 hours, the patient was stable and transferred to the cardiology ward. Antibiotic therapy was then changed to Meropenem and Cloxacillin.
The transthoracic echocardiogram (TTE) showed no abnormalities. Transesophageal echocardiogram (TEE) was not performed due to the patient’s rejection of this procedure. On the 6th day of hospitalization, the patient asked to be discharged against medical advice. The antibiotic therapy was discontinued.
Two days later, the patient returned to the emergency department with persistent fever and signs of right heart failure in physical examination. The patient was then readmitted and antibiotic therapy with Daptomycin and Cloxacillin was started. The chest X-Ray showed bilateral mild pleural effusions and images suggesting bilateral multilobar pneumonic foci similar to pulmonary septic embolisms (Figure_1).
A new TTE was performed on suspicion of right heart IE, but showed no abnormal findings. TEE was then performed showing nodular images on the PV suggestive of large vegetations (Figure_2) causing substantial valve destructuration and severe pulmonary regurgitation (IV/IV) (Figure_3). Tricuspid regurgitation was mild without suggestive signs of IE. The rest of the study was normal.
The case was accepted for urgent surgery. Among the different techniques for the reconstruction of the pulmonary valve have been described, a biologic valve replacement according to Kogon’s technique4 was the chosen procedure. On the surgical field, a severely unstructured PV with large vegetations anchored to the anterior and right leaflets was identified (Figure_4). There was also an infra-annular abscess, not visualized in the TEE, rightly below the left leaflet that spread through the posterior infundibular wall with no signs of perforation.
Once the vegetations were excised, the abscess was also drained, cleaned and finally closed with a bovine pericardial patch (Figure_5). The pulmonary valve was replaced with a bioprosthetic valve. The main pulmonary artery and right ventricular infundibulum were reconstructed with another bovine pericardial patch (Figure_6).
The intraoperative TEE showed no paravalvular leaks with a normal functioning prosthesis. The patient experienced an uncomplicated postoperative period, being extubated immediately after surgery and transferred to the ward 48 hours later.
A postoperative computed tomography scan showed images suggestive of bilateral pulmonary septic embolisms and thromboembolisms with infarcts (Figure_7) The microbiological test of the valve confirmed IE caused byStaphylococcus aureus .
The patient was discharged once the antibiotic therapy was completed and remains asymptomatic.