Intraosseous Tenecteplase During Refractory Cardiac Arrest Associated with Anteroseptal STEMI: A Case of Angiographic TIMI 3 Flow following ROSC

Background Rapid reperfusion is critical in ST-elevation myocardial infarction (STEMI), but cardiac arrest often causes vascular collapse that makes peripheral intravenous (IV) access difficult. Intraosseous (IO) access is a well-established route in cardiac arrest, but IO systemic fibrinolysis for STEMI has been reported only once previously. Intra-arrest thrombolysis in unselected patients is not routinely indicated, but its role during active cardiopulmonary resuscitation (CPR) when STEMI is the known cause of arrest is not well studied. We report a case with angiographic documentation of coronary patency after IO tenecteplase (TNK) during active CPR. Case Report A 74-year-old man presented with acute anteroseptal STEMI complicated by ventricular fibrillation arrest. Attempts at peripheral IV and femoral central venous access were unsuccessful, so an IO catheter was placed. Given the known STEMI etiology and inability to deliver percutaneous coronary intervention during ongoing arrest, an IO weight-based TNK bolus was given. Return of spontaneous circulation (ROSC) occurred within twenty minutes. Post-ROSC coronary angiography performed before any mechanical intervention demonstrated Thrombolysis in Myocardial Infarction grade 3 (TIMI 3) flow in the presumed culprit vessel, the proximal left anterior descending artery. The post-arrest course was complicated by severe gastrointestinal hemorrhage. Conclusion This case demonstrates that IO TNK can be delivered during active CPR. Although causality cannot be established from this single case, ROSC and TIMI 3 flow in the presumed culprit vessel followed IO TNK administration, adding to the sole prior report of IO TNK in STEMI. The fatal hemorrhage underscores substantial bleeding risk of systemic fibrinolysis.