Infective endocarditis following percutaneous pulmonary valve replacement: Diagnostic challenges and application of intra-cardiac echocardiography

BackgroundInfective endocarditis (IE) following percutaneous pulmonary valve replacement (PPVR) with the Melody valve is rarely reported. Furthermore, there are challenges in this diagnosis; especially echocardiographic evidence of vegetation within the prosthesis may be difficult.Method and resultThis study is a retrospective review of all patients with Melody valve implantation in a tertiary centre. Between November 2006 and November 2012, 43 procedures were performed in 42 patients (mean age 25 years, 6-67 years). At a median follow-up of 27 months (2-66 months), six patients were suspected for IE. However, repeated transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) showed no evidence of IE and the patients were diagnosed as possible cases according to the modified Duke's criteria. Two patients did not respond to antibiotic treatment and underwent intra-cardiac echocardiography (ICE), which clearly demonstrated vegetations. These two cases required surgical explantation, while the other four patients were treated medically without complications.ConclusionIE after Melody valve implantation is uncommon, but difficult to verify since TTE and TEE often cannot demonstrate vegetations inside the stent. ICE should be considered in suspected cases of IE following PPVR with negative TTE and TEE examinations in order to early tailor the best treatment for the individual patient suspected for IE.