Repetitive coronary thrombotic events after the cessation of intravenous heparin post percutaneous coronary intervention - Is it a case of heparin rebound phenomenon?

We report on a 72-year-old male with single vessel disease who underwent a percutaneous transluminal coronary angioplasty (PTCA) and stenting procedure smoothly without any procedure-related complications. Unfortunately, acute closure developed 2 hours after the procedure. The closure was re-opened using balloon dilatation and intra-coronary urokinase infusion. Heparin was administered for 3 days, however, myocardial infarction attacked 40 hours after cessation of heparin infusion. We immediately gave recombinant tissue-type plasminogen activator (rt-PA) treatment, then heparin was infused for another course of 3 days. Unfortunately, a second myocardial infarction event happened around 90 minutes after cessation of the second course of heparin infusion. There were no dissection, slow distal run-off or thrombus formation after this percutaneous coronary intervention. Heparin rebound phenomenon was considered when we encountered repetitive thrombosis events after the intervention procedure in this case. After the third thrombotic event, we treated the problem successfully using oral anticoagulant and tapering the heparin dose.