Abstract Body (Do not enter title and authors here): Background: Pericardial tamponade complicates fibrinolytic therapy in <1% of cases. However, recurrent hemopericardium post primary PCI that necessitates emergency cardiac surgery and mechanical circulatory support represents an unprecedented clinical scenario with no prior literature documentation.

Case Description: 63-year-old male with established diabetes and peripheral vascular disease presented with acute chest pressure radiating to neck, associated with dyspnea. Initial vitals were stable with electrocardiographic evidence of inferior STEMI. Given the nearest PCI-capable facility exceeding three hours transport time, tenecteplase was administered. This intervention was immediately complicated by clinically significant pericardial effusion requiring emergent pericardiocentesis. During interhospital transfer, the patient experienced ventricular tachycardia with cardiac arrest requiring resuscitation. Following ROSC, emergent catheterization revealed acute right coronary artery occlusion. Primary PCI achieved successful TIMI-3 flow restoration. Concurrent angiography demonstrated severe left main and proximal left anterior descending stenoses. Post-procedural persistent shock prompted immediate echocardiography, revealing recurrent pericardial effusion. Repeat pericardiocentesis with catheter drainage was performed. In the CCU, the patient developed progressive hemodynamic deterioration requiring high-dose vasopressor support. Transesophageal echocardiography confirmed recurrent effusion with tamponade without distinct rupture noted. Given refractory bleeding and extensive coronary disease, emergency surgery was undertaken with two-vessel bypass grafting and axillary Impella insertion for hemodynamic support. Surgical exploration revealed no cardiac rupture; however, diffuse pericardial inflammation with active bleeding was observed. Post-operative recovery proceeded favorably with successful mechanical support weaning and discharge to a rehabilitation facility.

Discussion: This case represents the first reported instance of recurrent post-fibrinolytic hemopericardium requiring emergency cardiac surgery. While ASSENT-2 documented 0.6% tamponade incidence with tenecteplase, persistent bleeding necessitating surgical intervention remains unreported. Pathophysiology likely involves synergistic effects of fibrinolytic-induced coagulopathy, mandatory dual antiplatelet therapy, and inflammatory pericardial response creating a self-perpetuating bleeding cycle.