Insights into a rare clinical phenomenon: Isolated native valve endocarditis subsequent to transcatheter prosthetic valve implantation

Introduction: Prosthetic valve endocarditis (PVE) is a known complication of prosthetic valve implantation (PVI). Native valve endocarditis (INVE) without concurrent PVE, or isolated native valve endocarditis (INVE), after PVI is largely unheard of in literature. This review aims to identify the factors that predispose to INVE along with management and complications of INVE. Methods: A review of four major databases was carried out to identify the incidence of INVE after various PVIs. INVE was compared to PVE in terms of patient demographics, PVI characteristics, pathogen types, management approaches, and outcomes. Results: INVE was found in 119/645 (18.4%) cases after transcatheter aortic valve implantation (TAVI) and 9/138 (6.5%) cases after surgical aortic valve implantation (SAVI). INVE case distributions in the TAVI cohort were 87/119 (73.1%) on mitral valves and 32/119 (26.9%) on right heart valves. Corevalve implants were more closely linked to INVE than to transcatheter aortic valve implant endocarditis (TAVIE) at 67/119 (56.3%) vs 240/526 (45.6%) (OR = 1.55, CI 1.02–2.29, p = 0.036). Surgery was performed less frequently in INVE than TAVIE at 9/119 (7.6%) vs 130/526 (24.7%) (RR = 0.31, CI 0.16–0.58, p = 0.001). In hospital mortalities were less frequent in INVE than TAVIE at 22/119 (18.5%) vs 170/526 (32.3%) (RR 0.65, CI 0.45–0.94, p = 0.015). Conclusion: INVE makes up a measurable proportion of endocarditis cases after TAVI and frequently manifests on mitral valves. Compared to TAVIE, INVE is more likely to occur after Corevalve PVI, is amenable to medical therapy, and has lower rate of in hospital mortality. Surgical and non-aortic PVI based INVE is less frequently reported on and warrants investigation.