APCU25MPB5 When everything should have gone wrong – a rare survivor of ruptured mycotic aneurysm in an immunocompetent patient with infective endocarditis due to MSSA

Introduction Mycotic aneurysm is a rare but severe complication of infective endocarditis (IE), occurring in approximately 2% of cases. Staphylococcus aureus is the most common causative organism due to its high virulence, often resulting in embolic events and vascular complications. Rupture of these aneurysms can lead to catastrophic intracranial hemorrhage, with mortality rates exceeding 30–60%. Timely neurosurgical and medical management, combined with planning of definitive cardiac surgery, is critical. We present a rare case of survival following a ruptured mycotic aneurysm due to methicillin-sensitive S. aureus (MSSA) IE.Case Presentation A 56-year-old gentleman with no known comorbidities presented with a spontaneous right frontal intracerebral haemorrhage. Emergency CT brain revealed haemorrhage secondary to a ruptured mycotic aneurysm. He underwent urgent craniotomy with clot evacuation and nidus excision. Postoperative imaging showed minimal residual clot and reversal of mass effect. His recovery was complicated by a wound hematoma requiring revision craniotomy and tracheostomy for prolonged ventilation. He developed focal seizures managed with antiepileptic medications. Blood cultures grew MSSA. Transthoracic echocardiography revealed severe mitral regurgitation with vegetations and preserved ejection fraction (62%). He completed a 6-week course of intravenous cloxacillin. Definitive mitral valve surgery was delayed. During elective admission for coronary angiography (CAG), he experienced seizures and was managed with diazepam, phenytoin, and levetiracetam. CAG later revealed mild ectatic coronary disease and severe mitral regurgitation. He was discharged ambulatory with seizure control and mild dysarthria. He is planned for surgical mitral valve replacement later.Discussion MSSA IE poses high risk for embolic complications, including ruptured cerebral mycotic aneurysms. Neurological sequelae, such as seizures are common post-haemorrhage. Immediate neurosurgical intervention is lifesaving in this case. Timing of cardiac surgery post-intracranial haemorrhage remains controversial. Guidelines suggest delaying valve surgery at least 4 weeks unless urgent indications arise. This patient‘s case supports a delayed, individualized surgical approach. Literature reports similar cases of successful delayed valve surgery with favourable outcomes.Conclusion This case highlights the virulence of MSSA in IE, the complexity of managing ruptured mycotic aneurysms and the potential for recovery with a multidisciplinary, staged approach. Delayed cardiac surgery may be appropriate in stable patients after hemorrhagic complications.