Very Early-Onset Prosthetic Valve Endocarditis Following Transcatheter Aortic Valve Implantation Complicated by an Aorto-Left Atrial Fistula and Aortic Root Pseudoaneurysm

Transcatheter aortic valve implantation (TAVI) is an established treatment for severe aortic stenosis.Infective endocarditis (IE) is an uncommon but potentially devastating complication, typically presenting weeks to months after valve implantation.Very early-onset prosthetic valve endocarditis (PVE), occurring within 48 hours of implantation, poses a particular diagnostic challenge, as infectious complications must be distinguished from procedure-related structural injury and sterile postprocedural inflammatory changes.We report the case of an 81-year-old man who underwent transfemoral TAVI with a self-expanding Evolut FX valve for severe symptomatic aortic stenosis.The procedure was uneventful, with satisfactory immediate angiographic and echocardiographic findings.Within 48 hours, the patient developed fever and elevated inflammatory markers.Two independent blood culture sets were positive for methicillin-susceptible Staphylococcus aureus (MSSA).Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) demonstrated increased metabolic uptake at the aortic root.Given the early postprocedural timing, this finding was interpreted cautiously, as sterile inflammatory changes could not be excluded.Subsequent transesophageal echocardiography (TEE) revealed a prosthetic valve vegetation, an aortic-root pseudoaneurysm, and an aorto-left atrial fistula with continuous shunt flow.The combination of microbiological and echocardiographic findings fulfilled the diagnostic criteria for definite prosthetic valve IE.Surgical intervention was considered prohibitive by the multidisciplinary Heart Team, and antimicrobial treatment was administered.Despite treatment, the patient's clinical condition rapidly deteriorated, resulting in death within one week of diagnosis.This case highlights the importance of integrating clinical and microbiological findings with multimodality imaging in diagnosing very early-onset PVE, while carefully considering potential procedure-related structural injury.