Acute ST-elevation myocardial infarction due to in-stent thrombosis after administering tranexamic acid in a high cardiac risk patient.

Tranexamic acid (TXA) is an antifibrinolytic which minimises bleeding and transfusions, with thrombotic risk. Our patient had known coronary artery disease with post-TXA acute ST-elevation myocardial infarction (STEMI) due to in-stent thrombosis. He had five drug-eluting stents (DES): two overlapping DES in mid-LAD (3 years ago), and two overlapping DES in distal right coronary artery and one DES in obtuse-marginal (1.5 years ago). After TXA, both overlapping stent locations thrombosed. Of nine reports of post-TXA acute MI, only one had complex stent anatomy (bifurcation stent to left circumflex/first obtuse-marginal) with other single stents, and only the complex stent thrombosed. Post-TXA MI was more often STEMI caused by arterial thrombosis, rather than non-STEMI caused by blood loss, hypotension or demand ischaemia. Overlapping and bifurcation stents thrombosed; single stents remained patent. In conclusion, overlapping stents, bifurcation stents, excessive stent length and previous in-stent restenosis/thrombosis may increase thrombotic risk. TXA should be administered cautiously with complex stent anatomy.