Risk-benefit of thrombolysis.

In larger trials the relative reduction in mortality rates brought about by thrombolytic therapy is similar among various subgroups. Accordingly, the absolute mortality reduction by thrombolytic therapy is largest in patients with the greatest expected mortality in the placebo groups. Similarly, the additional benefit by accelerated tissue plasminogen activator (TPA) is proportional to the expected mortality without thrombolytic therapy. Using logistic regression analysis a table has been developed predicting the survival benefit from thrombolytic therapy in groups of patients with different baseline characteristics. A table also has been developed to predict the risk of intracranial hemorrhage from thrombolytic therapy. Using these two tables, an individual risk/benefit assessment can be made. In most patients the benefits of thrombolytic therapy far exceed the risk of intracranial hemorrhage. Similarly, the advantage of more intensive therapy (accelerated TPA) exceeds the slightly increased bleeding risk. The model presented can help to allocate different modes of reperfusion therapy to individual patients, accounting for limited resources.