A case report of giant coronary artery pseudoaneurysm and infective endocarditis: at what level can two pathologies be interconnected on a suitable background?

Coronary artery pseudoaneurysm (PSA) is a rare but potentially life-threatening condition, typically occurring after percutaneous coronary intervention (PCI). Giant coronary PSA in patients without prior coronary procedures is exceedingly uncommon. Mycotic involvement, particularly with Staphylococcus aureus, may accelerate pseudoaneurysm progression and significantly worsen prognosis.

We report the case of a 38-year-old man on long-term haemodialysis who presented with unstable angina and new electrocardiographic changes. Coronary angiography revealed severe proximal left anterior descending artery stenosis with a giant PSA. Surgical repair was deemed prohibitive due to marked vascular fragility; thus, emergent PCI with covered stent implantation was performed, achieving satisfactory angiographic exclusion. The patient was discharged in stable condition. One week later, he returned with fever, haemoptysis, and sepsis. Imaging demonstrated a new pulmonary valve vegetation, establishing the diagnosis of infective endocarditis due to S. aureus. Despite targeted antibiotic therapy, the vegetation showed progressive enlargement and evidence of embolization. The patient subsequently developed fulminant septic shock and died 12 days after readmission.

This case illustrates the diagnostic and therapeutic challenges of a giant coronary pseudoaneurysm occurring in a haemodialysis patient without prior coronary intervention. Although infection was clinically recognized only after pseudoaneurysm treatment, the later development of S. aureus endocarditis raises the possibility that asymptomatic bacteraemia was already present at the initial presentation. The case underscores the importance of maintaining a high index of suspicion for infection in vulnerable patients and of initiating early, individualized management to prevent rapid disease progression and adverse outcomes.