Occult Bartonella Quintana Infective Endocarditis Incidentally Diagnosed During Pre-Transcatheter Aortic Valve Implantation (TAVI) Workup in a Patient Without Classical Risk Factors

Bartonella infective endocarditis (IE) is a rare cause of initially blood culture-negative IE, classically associated with cat flea exposure in Bartonella henselae infection or body lice infestation among individuals experiencing homelessness or alcoholism in Bartonella quintana infection.We report the case of an 84-yearold man with severe calcific aortic stenosis who was undergoing evaluation for pre-transcatheter aortic valve implantation (TAVI).Cardiac computed tomography (CT) unexpectedly revealed a peri-annular cavity consistent with a drained or healed peri-annular abscess, despite the absence of fever or other clinical features of IE.Initial blood cultures were negative, and TAVI was planned following multidisciplinary discussion, pending serological results.However, a subsequently reported high-titer Bartonella serology prompted readmission, and TAVI was ultimately deferred after the diagnosis was confirmed.Prolonged incubation of blood cultures subsequently identified B. quintana, while brain magnetic resonance imaging (MRI) revealed a lesion suspicious for an intracranial infectious aneurysm.Definite IE was established according to the 2023 Duke-International Society for Cardiovascular Infectious Diseases (Duke-ISCVID) criteria based on two major criteria: high-titer Bartonella serology and imaging evidence of a peri-annular abscess.No classical epidemiological risk factors for Bartonella infection were identified.Despite targeted antimicrobial therapy, the patient experienced progressive clinical deterioration, and multiple comorbidities precluded surgical intervention.He ultimately died of multiorgan failure.This case highlights the diagnostic challenge of occult B. quintana IE incidentally identified during pre-TAVI evaluation, including in patients without classical epidemiological risk factors or overt manifestations of infection.It also emphasizes that unexpected peri-annular abnormalities detected during pre-TAVI evaluation should prompt a thorough investigation for IE, even in clinically unsuspected cases, with direct implications for procedural planning.