ABSTRACT
The authors describe 2 cases of extensive intracoronary thrombus formation leading to acute closure of the left main where bivalirudin (Angiomax) was used as the anticoagulant during percutaneous coronary intervention leading to mortality. Both cases had similarity in the cascade of complications of coronary dissection leading to slow flow and prolonged procedure time with compromise of antegrade flow in the coronary artery and a final catastrophic development of extensive intracoronary thrombosis extending into the left main and nonintervened vessel (left anterior descending or circumflex) followed by ventricular fibrillation and death. Bivalirudin has reversible anticoagulant pharmacodynamics because the bivalirudin molecule is cleaved by the thrombin molecule. In situations when the antegrade flow is compromised, delivery of fresh circulating bivalirudin to replenish the catalysis of bivalirudin by thrombin is diminished, allowing thrombin activity to regenerate, thereby creating a prothrombotic milieu in these coronary segments. This can lead to extensive intracoronary thrombus formation in situations of slow flow precipitated by coronary dissection and prolonged dwell time with intracoronary hardware (wires, balloons, and stents). Interventionalists should be aware of the potential risk of this fatal complication and should be proactive in recognizing the scenarios where this is likely to occur. In such anticipated circumstances, the interventionalist may judiciously switch the anticoagulant to heparin and/or use additional glycoprotein IIb/IIIa inhibitor because freshly formed intracoronary thrombus is susceptible to lysis by glycoprotein IIb/IIIa inhibitors.
