Lack of impact of early catheterization and fibrin specificity on bleeding complications after thrombolytic therapy

Abstract

Objectives. The aim of this study was to assess the hemorrhagic risk associated with fibrin-specific thrombolytic therapy and invasive procedures with acute myocardial infarction.Background. Successful coronary artery reperfusion has important prognostic implications. Because immediate coronary angiography is the only method proved to differentiate early fibrinolytic success from failure, its use may be important for selected patients.Methods. Five hundred seventy-five patients were evaluated with six combined thrombolytic and catheterization strategies. Patients were randomized to intravenous urokinase alone, recombinant tissue-type plasminogen activator (rt-PA) alone, or both; simultaneously they were randomized to an immediate versus a deferred catheterization strategy. Hemorrhagic events were assessed. The correlation of hemorrhage with clinical and hemostatic variables was evaluated. Prespecified transfusion criteria were employed.Results. No difference in baseline characteristics or in hemorrhagic complications was noted among the three thrombolytic regimens. Although mild (<250 ml) bleeding was more common in the group with immediate catheterization, no clinically significant difference among catheterization groups was seen in moderate to life-threatening hemorrhagic events. Most bleeding occurred at vascular access sites, yet severe and life-threatening hemorrhage occurred in < 1 % of patients. Baseline and nadir fibrinogen levels, change in baseline fibrinogen levels and peak fibrin and fibrinogen degradation products did not correlate with bleeding risk. A clinical predisposition for bleeding was observed in women as well as older (>-65 years) and lighter (<-70 kg) patients. With prespecitied transfusion criteria, only a minimal increase in blood product usage was noted with immediate catheterization.Conclusions. Immediate cardiac catheterization can be accomplished without a clinically significant difference in bleeding risk. Fibrin specificity offers no clear advantage in reducing hemorrhagic risk. Bleeding risk correlates bese with baseline patient characteristics. Finally, the amount of blood transfused can be reduced with lower transfusion criteria.