Variation in von Willebrand's Factor according to the treatment of acute myocardial infarction: physiopathological and clinical implications

To investigate whether von Willebrand's Factor (vWF) changesas a result of the reperfusion strategy during acute myocardialinfarction (AMI), vWF was measured on days 0, 1, 2, 3, 4, 5and 15 in 34 patients with AMI. Thrombolysis was initiated in22 patients and followed by a coronary angiogram 90 min later.In 13 patients the infarct-related artery was then patent (THRgroup). In nine patients the infarct-related artery was occludedand rescue percutaneous transluminal coronary angioplasty wasperformed (group THR+rPTCA). In 12 patients, primary PTCA wascarried out (pPTCA group). Admission values of vWF were similarlyhigh in the three groups, while changes in vWF over the followingdays were statistically different among the groups. No significantchange was observed in THR, whereas a significant and prolongedincrease was found after failed thrombolysis with PTCA (peakincrease at day 5:1·54±;0·04 U. ml^–1).In the pPTCA group, a significant increase could only be foundon day 3 (0·96 ±; 0·04 U. ml^–1).Absence of a statistical rise in vWF might be a late indicatorof successful thrombolysis. The prolonged increase in vWF afterfailed thrombolysis needing rescue PTCA probably reflects ahigher resistance to thrombolysis, While the slight but significantincrease in vWF following primary PTCA could be due to vascularinjury.