Thrombin and antithrombotic therapy in interventional cardiology.

Despite developments in percutaneous transluminal coronary angioplasty, the success of this treatment method remains clouded by early and late reocclusion. Increased experience, advances in technology, and the introduction of adjunctive devices have contributed to a higher procedural success rate (90% to 95%) and to a lower complication rate (4% to 5%), in spite of the expanded indications for angioplasty. Late renarrowing of the treated coronary artery, in combination with recurrence of angina pectoris, occurs in 15% to 40% of angioplasty patients. Several multicenter randomized trials of pharmaceutical agents have been conducted or are in progress, in an effort to diminish the rate of late reocclusion. No major breakthrough has been reported, although a clear progression has been made in the understanding of the restenosis phenomenon. It is evident that thrombin plays a detrimental role in the vascular wall injury resulting from angioplasty procedures. Current pharmacologic research concentrates on direct inhibition of prothrombin conversion and thrombus formation. Animal experimental work in this field is encouraging, and the results of clinical trials will elucidate important questions about the safety, efficacy, and immuno-allergic potential of modern antithrombotic medication.