[Heparin activity during percutaneous coronary angioplasty]

In the experimental model of porcine carotid artery angioplasty, whenever a deep lesion--involving the media--is produced, thrombus deposition invariably follows. It has been shown that the thrombus formation can be prevented by heparin administration, albeit at higher doses than usually employed in the clinical setting. In patients with unstable angina and acute myocardial infarction there appears to be a hitherto ill-defined thrombogenic state and, in fact, percutaneous transluminal coronary angioplasty is still plagued by a higher incidence of acute reocclusion in such conditions. It appears reasonable to infer that during percutaneous transluminal coronary angioplasty higher dose of heparin should be infused, under close monitoring, particularly in such patients. However, at the moment this remains an unproven hypothesis that needs careful clinical testing.