Prosthetic valve endocarditis after transcatheter CoreValve Evolut R bioprosthesis implantation

Prosthetic valve endocarditis (PVE) affects 1–6% of prosthetic valve recipients and in patients treated with transcatheter aortic valve implantation (TAVI) has an incidence of 0.3–2.3% per patient-year [1–3]. A 79-year-old man who underwent TAVI with a Med-tronic Evolut R 29 mm bioprosthesis 7 months earlier was admitted due to recurring episodes of fever up to 39°C and mild worsening of exercise tolerance lasting for 4 months. Other relevant medical history consisted of chronic obstructive pulmonary disease (COPD) and penicillin allergy. During the past months the patient was hospitalized twice (once due to fever, the second time due to syncope), but the symptoms were attributed to COPD exacerbation. At admission, physical examination was remarkable for systolic murmur over the mitral valve. No fever, chest pain, cough, or meningeal signs were appreciated. Elec-trocardiogram (ECG) demonstrated sinus rhythm with left bundle branch block observed in previous ECGs. Chest X-ray revealed an enlarged cardiac silhouette. Transtho-racic echocardiography (TTE) demonstrated mild mitral regurgitation (Figure 1 A) and 15 mm hyperechogenic structures on the mitral valve described as possible vege-tations (Figure 1 B). Laboratory findings revealed a white blood cell count of 19 × 10 3 /μl, N-terminal prohormone of brain natriuretic peptide of 1000 pg/ml and C-reactive protein of 123 mg/l. Due to high clinical suspicion of PVE, the patient was started on vancomycin, gentamicin and rifampin. Beforehand , three sets of blood cultures were collected, which were found to be positive for methicillin-sensitive Staphylococcus capitis. Transesophageal echocardiography (TEE) confirmed PVE demonstrating vegetations on the leaflet located in the vicinity of the native right coronary cusp (Figures 1 C and D). Further treatment with rifamp-in and gradually increased doses of vancomycin (genta-micin was discontinued after 2 weeks due to transitory worsening of the renal function) led to clinical improvement , whilst laboratory examinations showed C-reactive protein and white blood cell (WBC) normalization. Even though repeated TEEs demonstrated persistence of veg-etations, clinically the PVE was deemed healed. After 6 weeks antibiotics were discontinued, blood cultures were negative and the patient was discharged. A recent study [2] on 7944 patients found two independent factors associated with infective endocardi-tis (IE) prevalence – orotracheal intubation and use of self-expandable CoreValves. Among factors possibly responsible for PVE prevalence in the cohort treated with CoreValves, the following were suggested: larger stent frame, larger contact surface area between tissues and the frame, and paravalvular leak (PVL). In another study [4] risk factors …