t-Plasminogen activator and von Willebrand factor in patients with unstable angina.

We investigated whether the clinical evolution of symptoms in patients admitted with unstable angina is associated with changes in t-plasminogen activator antigen (t-PA) and von Willebrand (vW) factor levels. Concentrations of vW factor antigen and t-PA antigen were measured by an enzyme-linked immunoassay method in 10 patients who became clinically stable within 24 h of admission and remained so for 5 days. A significant rise in morning t-PA plasma level occurred 24 h after the admission (15.15 +/- 2.1 ng/ml, P < 0.05), whereas the vW factor remained unchanged. No significant changes were found in the night concentration in t-PA and vW factor during the 5 day period. Thus t-PA level is significantly raised 24 h after admission in patients with unstable angina who stabilize in response to medical treatment.