A pilot study of streptokinase-induced endothelial injury and platelet activation following acute myocardial infarction

Objective. To relate the changes in serum vitamin E, an essential antioxida nt, to changes in fibrinogen, as well as indices of endothelial damage [as indicated by plasma markers, soluble thrombomodulin (sTM) and von Willebran d factor (vWf)], and an index of platelet activation [soluble P selectin (s Psel)], in myocardial infarction treated with thrombolytic therapy. Design and Setting. Prospective longitudinal pilot study in a teaching hosp ital Coronary Care Unit. Subjects and intervenions. Seventeen patients (12 men; mean age 62 years +/ - SD 11 years) admitted with acute myocardial infarction (AMI), who were gi ven thrombolytic therapy, and 59 healthy controls. Results. Baseline levels of fibrinogen (Mann-Whitney test, P = 0.0055) and vWf (P < 0.001) were significantly higher than controls, but sPsel, sTM or vitamin E levels were not significantly different. Following thrombolysis, as expected, median concentrations of plasma fibrinogen fell profoundly (Fr iedman anova P < 0.001) so that after 45 min, levels were undetectable in 1 3 patients. At 24-h median fibrinogen concentration had recovered to approx imately 30% of baseline (P < 0.01) and was still undetectable in three pati ents. Levels of vWf and sPsel increased steadily, reaching significance aft er three hours (both P < 0.05). However, levels of sTM rose immediately aft er thrombolysis, peaking between 1 and 3 h, and remained elevated at 24 h. These increases corresponded to a simultaneous early fall in serum vitamin E concentrations. Conclusion. The present pilot study demonstrates significant endothelial da mage and platelet activation in association with increased oxidative stress following streptokinase therapy for AMI.