Acute myocardial infarction complicating recanalization of aortocoronary bypass grafts with urokinase therapy

Abstract

The progressive occlusion of aortocoronary bypass grafts over time an important clinical problem. Studies have demonstrated closure rates of approximately 3% at 1 month 1 and 11 to 14% at 1 year. 2,3 Closure rates as high as 40 to 50% at 10 years are reported. 4,5 Thrombosis seems to be the major cause of occlusion in the early postoperative period. 6–8 Late graft occlusions are thought to be due to atherosclerotic esions with or without associated thrombus. The use of percutaneous angioplasty in stenotic aortocoronary bypass grafts may be successful but is of limited use in grafts with complete occlusions. Success rates are lower and the risk of distal embolization is present. Therefore, mechanical recanalization using balloon angioplasty has been avoided in these patients. 9 We have previously reported the successful recanalization of chronically occluded aortocoronary bypass grafts using a prolonged, direct infusion of urokinase. 10,11 Our clinical experience was favorable and not associated with clinically important distal embolization. We now report 3 cases of thrombolytic recanalization of occluded aortocoronary bypass grafts complicated by acute myocardial infarction, and strongly suggest that the need for continued urokinase infusion is critical in the treatment of this potential complication.