Insights into a Rare Clinical Phenomenon: Isolated Native Valve Endocarditis After Prosthetic Valve Implantation

IntroductionProsthetic valve endocarditis (PVE) is a known complication of prosthetic valve implantation (PVI). The incidence of selective native valve endocarditis without concurrent PVE, or isolated native valve endocarditis (INVE), is much lower and largely unheard of in literature. MethodsWe examine here the specific circumstances in which INVE manifests as well as management and complications of this rare form of endocarditis. A systematic review of four major databases was carried out to identify INVE and PVE cases after various PVIs. INVE was compared to PVE across categories such as patient demographics, method and type of PVI prior to endocarditis, pathogen type, management, and outcomes. ResultsINVE comprised 18.2 % of valvular endocarditis cases after transcatheter aortic valve implantation (TAVI) and 6.5 % of valvular endocarditis cases after surgical aortic valve implantation (SAVI). In the TAVI group, mean age of the INVE cohort was 79.5 +- 5 years and it was observed more frequently among males. Prior to most INVE cases, TAVI had been performed by transfemoral route. INVE was more closely linked to diabetes (DM) and chronic obstructive pulmonary disease (COPD) than TAVIE (transcatheter aortic valve implant endocarditis). INVE was less closely linked to chronic kidney disease (CKD) than TAVIE. Gram positive infection rates were similar between the groups. Surgery was done less frequently after INVE than TAVIE. Compared to TAVIE, INVE mortalities were more likely to occur at follow up and were linked to heart failure, renal failure, and septic shock. Total long term mortalities were similar between the two groups. ConclusionINVE makes up a measurable proportion of endocarditis cases after TAVI and shares characteristics, predictors, pathogens, and outcomes linked to TAVIE. Compared to TAVIE, INVE is more closely linked to DM and COPD and less to CKD. It manifests more on mitral valves than right heart valves and presents higher rates of delayed mortality. Given INVEs long term mortality and ability to manifest on different valves, thorough cardiac evaluation and close long term follow up should be considered if endocarditis is suspected after TAVI. Non-mitral INVE and surgical implant based INVE are less frequently reported on and warrant further investigation. Key PointsO_ST_ABSQuestionC_ST_ABSWhat are the incidence, associations, predictors, implicated causes, and outcomes of selectiveand isolated native valve endocarditis following prosthetic valve implantation? FindingsThis systematic review found that isolated native valve endocarditis was reported most frequently after transcatheter aortic valve implants and particularly in mitral valves. Infrequently, isolated native endocarditis has also been reported in right heart valves and after surgical aortic valve implants. Diabetes and pulmonary disease are associated with isolated native endocarditis after transcatheter implants. MeaningThe development of isolated native mitral valve endocarditis should be closely screened for in diabetic and pulmonary patients with transcatheter aortic valve implants. This phenomenon needs further study in non-aortic, non-transcatheter, and non-mitral endocarditis populations. Moreover, patients with this rare endocarditis require close long term follow up as mortalities after hospitalization are significantly higher than in hospital.