Infective Endocarditis after Transcatheter Aortic Valve Replacement: Challenges in the Diagnosis and Management

Abstract

Although initially conceived for high-risk patients who are ineligible for surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR) is now recommended in a wider spectrum of indications including young patients. However, as for SAVR, TAVR is also associated with a risk of infectious complications, namely prosthetic valve endocarditis (PVE). As the number of performed TAVR procedure increases, and despite the low incidence of PVE post TAVR, clinicians should be familiar with the associated risk factors and the clinical presentation. Whereas the diagnosis of native valve endocarditis can be straightforward applying the modified Duke criteria, the diagnosis of PVE is more challenging given its atypical symptoms, lower sensitivity of the criteria, and low diagnostic yield of conventional echocardiography. Delay in proper management can be associated with increased morbidity and mortality. Therefore, clinicians should have a high index of suspicion and initiate proper work-up according to the severity of illness, the underlying host, and the local epidemiology of the causative organisms. The most common causative pathogens are Gram-positive bacteria such as S. aureus, coagulase negative staphylococci, Enterococcus spp. and Streptococcus spp. (particularly the viridans group) and, less likely Gram-negative and fungal pathogens. The high prevalence of antimicrobial resistance complicates the choice of therapy. There remain controversies regarding the optimal management strategies including indications for surgical interventions. Surgical assessment is recommended early in the course of illness and surgical intervention should be considered in selected patients. As in other PVE, duration of therapy depends on the isolated pathogen, the host, and the clinical response. Since TAVR is a relatively new procedure, the outcome of TAVR-PVE is yet to be fully understood.