Silent Cardiac Rupture Unmasked by Routine Echocardiography During Persistent Staphylococcus aureus Bacteremia

BACKGROUND: Postinfarction mechanical complications are rare in the primary percutaneous coronary intervention era. We report a silent, contained left ventricular free wall rupture driven by persistent staphylococcal bacteremia in an immunomodulated patient. CASE SUMMARY: A 64-year-old man with active ulcerative colitis on corticosteroids and vedolizumab presented with an anterior ST-segment elevation myocardial infarction, complicated by early stent thrombosis. He developed persistent Staphylococcus aureus bacteremia; transesophageal echocardiography excluded endocarditis. Although clinically stable, routine echocardiography on postinfarction day 24 detected a silent contained free wall rupture. Surgery revealed hemato-purulent pericardial effusion with culture-confirmed Saureus. After initial recovery, a ventricular septal defect developed, requiring percutaneous closure. The patient died 2 months postinfarction. DISCUSSION: To our knowledge, this is the first antemortem diagnosis of sequential postinfarction mechanical complications driven by confirmed staphylococcal infection of necrotic myocardium without endocarditis. TAKE-HOME MESSAGES: Persistent Saureus bacteremia after infarction warrants comprehensive evaluation beyond endocarditis. Structured echocardiographic surveillance can detect silently evolving mechanical complications.