Registry of Multicenter Clinical Trials: Twelfth and Thirteenth Report – 1990–1991

Streptokinase in acute ischemic stroke: an individual patient data meta-analysis : The Thrombolysis in Acute Stroke Pooling Project

BACKGROUND AND PURPOSE

Three major randomized controlled trials of streptokinase in acute ischemic stroke were curtailed because of safety concerns. The prospective Thrombolysis in Acute Stroke Pooling Project (TAS-PP) was established to examine the aggregate data to identify factors influencing the effect of streptokinase.

METHODS

Individual patient data from the Australian Streptokinase Trial (ASK), Multicentre Acute Stroke Trial-Europe (MAST-E), Multicentre Acute Stroke Trial-Italy (MAST-I), and Glasgow Trial (Glasgow) were pooled. Multivariate modeling determined the interaction between treatment effect and delay from symptom onset to treatment, predicted baseline risk, age, concomitant aspirin or heparin use, and the presence of early CT signs on the outcomes of 10-day death, death and disability, or death alone at 3 or 6 months.

RESULTS

Patients' records were pooled (total 1292 patients; streptokinase, n=653, no streptokinase n=639). The subgroup analysis of treatment effect according to delay from symptoms to inclusion shows only a trend toward a better treatment effect with shorter delay, which is not statistically significant for any outcome. Heavier patients in MAST-E may have had a lower (non significant) risk from the fixed dose of 1.5 million units of streptokinase. Concomitant aspirin increased the excess mortality rates in streptokinase-treated patients (17% without aspirin versus 91% with aspirin, P=0.005). The presence of early CT scan signs did not increase the detrimental effect of streptokinase.

CONCLUSIONS

Few factors influenced the response to streptokinase. However, earlier administration, lower doses of streptokinase, and avoidance of concomitant aspirin should be considered if further streptokinase trials in acute stroke are planned.

Thrombolytic therapy with streptokinase in acute ischemic stroke

BACKGROUND

In patients with acute ischemic stroke, early treatment with thrombolytic agents is thought to permit reperfusion of ischemic neurons and to promote recovery of function. The Multicenter Acute Stroke Trial-Europe (MAST-E) was designed to assess the efficacy and safety of streptokinase in patients with acute ischemic stroke.

METHODS

Patients with moderate-to-severe ischemia in the territory of the middle cerebral artery were randomly assigned to receive streptokinase (1.5 million units over a period of one hour) or placebo within six hours after the onset of stroke. The primary efficacy outcome was a binary criterion combining mortality and severe disability at six months, with severe disability defined as a score of 3 or higher on the Rankin scale. The primary safety outcomes were mortality at 10 days and cerebral hemorrhage.

RESULTS

All randomized patients (156 in the streptokinase group and 154 in the placebo group) were evaluated at six months. The incidence of the primary efficacy outcome was similar in the two groups (124 patients in the streptokinase group and 126 in the placebo group died or had a Rankin score > or = 3). However, the mortality rate at 10 days was significantly higher in the streptokinase group than in the placebo group (34.0 percent vs. 18.2 percent, P = 0.002). The higher rate in the streptokinase group was mainly due to the hemorrhagic transformation of ischemic cerebral infarcts. At six months, more deaths had occurred in the streptokinase group than in the placebo group (73 vs. 59, P = 0.06).

CONCLUSIONS

In patients with acute ischemic stroke, treatment with streptokinase resulted in an increase in mortality. The routine use of streptokinase cannot be recommended in acute ischemic stroke.