An impetuous "HIT"-sudden blockage of all grafts post CABG.

We report a case of hyperacute multiple graft thrombosis following an uneventful coronary artery bypass graft (CABG) surgery in a 69-year-old female with chronic immune thrombocytopenia (ITP). Detailed evaluation revealed the presence of anti-PF4/heparin antibodies, confirming the diagnosis of heparin-induced thrombocytopenia (HIT). The co-existence of chronic ITP masked the thrombocytopenia typically associated with HIT, complicating the recognition of the thrombotic and hematologic abnormalities. This case emphasizes the importance of promptly discontinuing heparin when HIT is suspected or confirmed. Additionally, maintaining a low threshold for suspecting HIT in patients with ITP undergoing cardiac surgery is crucial, as this complex interplay may increase the risk of severe postoperative complications.