Introduction Catheter-related right atrial thrombus (CRAT) is a rare yet potentially serious complication associated with central venous catheters. However, in the presence of MSSA bacteraemia, catheter-related septic thrombosis is suspected in this group of individuals.

Case Presentation We describe a 40-year-old woman with end-stage renal disease on regular haemodialysis via a central venous haemodialysis catheter who presented with intradialytic hypotension and fever for 2 days. Her past medical history was remarkable for diabetes mellitus, hypertension, and hyperlipidaemia. On examination, she was febrile with a temperature of 38.6°C and tachycardic. Other systemic examinations were unremarkable. Blood investigations showed white blood cells of 33.29 × 10³/uL with neutrophil predominance and a high CRP of 42.2 mg/L. In view of a history suggestive of catheter-related bloodstream infection, she was empirically treated with intravenous cefazolin and ceftazidime. Her blood culture and sensitivity from both lumens and periphery revealed MSSA. A transthoracic echocardiography (TTE) showed an echogenic intracardiac mass in the right atrial chamber measuring 7.1 cm × 6 cm × 5 cm, and this was subsequently confirmed with a trans-oesophageal echocardiogram. The catheter was removed, and we ultimately decided on a medical care plan that included 6 weeks of antibiotic therapy in addition to systemic anticoagulation with enoxaparin. At 6 weeks, full thrombus dissolution was seen on the surveillance TTE.

Discussion Septic thrombosis is defined as an infection of a thrombus. However, it is difficult to distinguish between catheter-related thrombosis and bacteraemia, which causes septic thrombosis. Long-term central venous catheters are known to independently increase the risk of venous thrombosis because the insertion can induce damage to the vascular wall and activate the intrinsic coagulation pathway. Anticoagulation should be considered for managing MSSA bacteraemia catheter-related venous thrombosis.

Conclusion This case highlights the necessity of maintaining a high index of suspicion for thromboembolic complications in patients with catheter placement. The presence of MSSA bacteraemia in the setting of catheter-related thrombosis may warrant prolonged intravascular antimicrobial therapy and the administration of anticoagulation therapy.