Very Early-Onset Prosthetic Valve Endocarditis Following TAVI with Aorto-Left Atrial Fistula and Aortic Root Pseudoaneurysm

Very early-onset prosthetic valve endocarditis occurring within 48 hours of transcatheter aortic valve implantation represents an extreme diagnostic challenge. An 81-year-old patient recently developed methicillin-susceptible Staphylococcus aureus bacteremia and perivalvular structural complications, highlighting the diagnostic value of transesophageal echocardiography in identifying these fatal infections.

Transcatheter aortic valve implantation is an established therapeutic option for addressing severe symptomatic aortic stenosis in patients facing high surgical risks or inoperable conditions. Yet, the intervention carries rare infectious risks. While typical prosthetic valve endocarditis normally emerges weeks or months following the procedure, exceptional instances develop within the first 48 hours following transcatheter aortic valve implantation. This compressed timeline creates clinical confusion, as treating clinicians must immediately differentiate acute infection from sterile postprocedural inflammation or mechanical injury sustained during device deployment. In a large U.S. cohort, the reported incidence of infective endocarditis after transcatheter aortic valve implantation was approximately 0.87% per year, and most cases occurred within the first year after implantation.

Treating an 81-Year-Old Patient Receiving a Valve

The clinical scenario involved an 81-year-old man presenting with severe symptomatic aortic stenosis who underwent transfemoral TAVI with a self-expanding Evolut FX valve. Completion angiograms demonstrated proper seating of the bioprosthesis introduced via the right femoral artery, supplemented by a contralateral 6-Fr left femoral arterial sheath for pigtail catheter positioning and potential management of vascular complications. A temporary transvenous pacing lead was introduced via the right internal jugular vein, and transfemoral transcatheter aortic valve implantation was selected after Heart Team assessment.

Very Early-Onset Prosthetic Valve Endocarditis Following TAVI with Aorto-Left Atrial Fistula and Aortic Root Pseudoaneurysm — Photo: sciencedirect.com

The patient deteriorated within the initial 48-hour window, developing a fever and methicillin-susceptible Staphylococcus aureus bacteremia. Two independent blood-culture sets obtained on consecutive days tested positive for methicillin-susceptible Staphylococcus aureus. Subsequent diagnostic imaging revealed severe perivalvular destruction.

Diagnosing Infections With Positron Emission Tomography and Transesophageal Echocardiography

Detecting very early-onset infections requires imaging coordination, though initial assessments face ambiguity. When medical personnel performed fluorodeoxyglucose positron emission tomography/computed tomography, the scan revealed early uptake that warranted caution because sterile postoperative inflammation could not be dismissed. Positron emission tomography does not provide definitive anatomical characterization of structural damage, while cardiac computed tomography can characterize perivalvular extension. Fluorodeoxyglucose positron emission tomography/computed tomography may provide complementary metabolic information in suspected prosthetic valve endocarditis, according to the 2023 European Society of Cardiology guidelines. The guidelines emphasize the role of the Endocarditis Team and the integration of echocardiography, cardiac computed tomography and nuclear imaging when clinically indicated.

Definitive answers arrived through transesophageal echocardiography, which revealed a prosthetic valve vegetation involving the recently implanted prosthetic valve, an aortic root pseudoaneurysm, and an aorto-left atrial fistula with continuous shunt flow. These anatomical abnormalities were identified on transesophageal echocardiography rather than inferred from fluorodeoxyglucose positron emission tomography/computed tomography. The newly implanted prosthetic valve constituted a predisposing minor criterion alongside documented fever.

Managing Antimicrobial Regimens and Rapid Clinical Deterioration

Management strategies for this patient category remain complex. Global use of transcatheter aortic valve implantation grows due to an aging population and proven cost-effectiveness, associated endocarditis features distinct epidemiological features because of patients’ advanced age and comorbidities, with enterococcal infections being more frequent currently, although this might change as indications expand to include younger and low surgical risk patients. Diagnosing transcatheter aortic valve implantation-associated endocarditis is challenging and requires a degree of clinical suspicion. Although expert consensus suggests enterococcal coverage in prophylactic antibiotics during transcatheter aortic valve implantation, there is no solid evidence to support this recommendation, and preventive measures beyond antibiotic prophylaxis should be implemented. For patients deemed ineligible for surgical intervention, tailored antimicrobial regimens are essential, encompassing specific drug choices and therapy duration, which may entail extended suppression.

Despite receiving aggressive antimicrobial therapy and supportive measures, the patient rapidly deteriorated into septic shock and multi-organ failure, succumbing within days of the initial diagnosis and prior to completing the planned therapeutic regimen; this case highlights the potential for a swiftly lethal trajectory when extensive perivalvular destruction occurs alongside surgical inoperability, reinforcing the need for prompt multidisciplinary evaluation. In a large U.S. cohort, the reported incidence of infective endocarditis after transcatheter aortic valve implantation was approximately 0.87% per year.