Prosthetic valve endocarditis after transcatheter aortic valve implantation: the incidence in a single-centre cohort and reflections on clinical, echocardiographic and prognostic features.

Aims: Transcatheter aortic valve implantation (TAVI) has recently developed into an accepted alternative to conventional surgery in high-risk patients. According to current data, post-TAVI prosthetic valve endocarditis (PVE) seems to occur very rarely. Methods and results: We followed the first 180 consecutive patients who underwent TAVI at our institution to assess safety and efficacy of the procedure. During follow-up (median, 319 days), PVE was seen more frequently than expected. By applying modified Duke criteria five cases could be confirmed (four early-onset and one late-onset PVE, four cases with "definite diagnosis" and one with "possible diagnosis") representing an estimated PVE incidence of 3.4% at one year. Two patients died subsequently. Clinical summaries of all cases are reported and compared to previously published case reports. Conclusions: According to our hypothesis, PVE might be particularly difficult to diagnose after TAVI, whereas TAVI-specific elderly patients might be exceptionally vulnerable. There exists little experience of TEE interpretation in post-TAVI endocarditis which should possess unique characteristics regarding, e.g., valve dehiscence or abscess formation. Therefore, echocardiography as a diagnostic tool often remains initially inconclusive. Because of incongruence between prosthetic device and calcified native aortic valve, some degree of paravalvular leak is common after TAVI. These paravalvular leaks as a nidus for infection, advanced age and abundant comorbidities might predispose TAVI patients for infective endocarditis .