Case Report: Extracorporeal membrane oxygenation in acute coronary syndrome: a rare case of massive left ventricular thrombus

Background: Left ventricular (LV) thrombus is a catastrophic complication during veno arterial-extracorporeal membrane oxygenation (VA-ECMO) support for cardiogenic shock, arising from a confluence of hemodynamic stasis, a prothrombotic state, and potential limitations of conventional anticoagulation monitoring. Case presentation: A 42-year-old man with acute inferior-wall ST-elevation myocardial infarction developed refractory cardiogenic shock during percutaneous coronary intervention, necessitating VA-ECMO initiation. Dual antiplatelet therapy and systemic heparinization (targeting an activated partial thromboplastin time of 50-80 s) were maintained. Results: Despite therapeutic anticoagulation, serial echocardiography documented the formation of a massive LV thrombus occupying >90% of the cavity within a 14 h interval on the fourth day of ECMO support. The patient subsequently deteriorated into refractory multi-organ failure, leading to withdrawal of care. Conclusion: This case underscores the rapidity and severity of LV thrombus formation in VA-ECMO patients with severe ventricular dysfunction. It highlights the critical need for proactive management, including multimodal anticoagulation monitoring and aggressive, individualized LV unloading strategies that may require escalation beyond intra-aortic balloon pump support to more direct decompression methods.