Abstract
BACKGROUND: Transcatheter aortic valve implantation (TAVI) is an established treatment for severe aortic stenosis in elderly and high-risk patients. However, prosthetic valve endocarditis (PVE) remains a rare but devastating complication. Its diagnosis is often delayed due to atypical clinical manifestations and the frequent occurrence of culture-negative endocarditis. CASE PRESENTATION: We report the case of a 68-year-old woman with a prior TAVI who presented with sacroiliitis, initially interpreted as a localized musculoskeletal infection. Subsequent evaluation revealed infective endocarditis involving the prosthetic aortic valve and the native mitral valve. Blood cultures remained negative, most likely due to prior antibiotic therapy, which complicated timely diagnosis. During hospitalization, the patient developed acute ST-segment elevation myocardial infarction (STEMI), caused by coronary septic embolization. DISCUSSION: Distinguishing septic emboli from thrombotic occlusion in the setting of STEMI complicating endocarditis is extremely challenging but essential, as therapeutic approaches diverge. While percutaneous coronary intervention is the standard treatment for thrombotic occlusion, it carries major risks of septic embolization, including stent infection, mycotic aneurysm, and uncontrolled sepsis. CONCLUSIONS: This case highlights the need for high clinical suspicion of PVE in atypical presentations, the diagnostic challenges of culture-negative endocarditis, and the therapeutic dilemmas posed by acute coronary complications without clear guideline-based solutions.