According to sub-analysis of the Stroke-Acute Ischemic NXY Treatment [SAINT] I and II Trials cohort studies, baseline antiplatelet therapy is associated with an increased risk of intracerebral haemorrhage after thrombolytic therapy for ischaemic stroke.
The investigators examined patients (n=965; mean age, 68 years, 57% male; 92% Caucasian) with acute ischaemic stroke who were treated with intravenous tissue plasminogen activator within 3 hours of symptom onset and were enrolled in the placebo arms of the SAINT studies.
Early CT changes were graded using the Alberta Stroke Program Early CT Score (ASPECTS). Post-tissue plasminogen activator symptomatic intracerebral haemorrhage was defined as a worsening in National Institutes of Health Stroke Scale of > or =4 points within 36 hours with evidence of haemorrhage on follow-up neuroimaging. Good clinical outcome was defined as a modified Rankin scale of 0 to 2 at 90 days.
The following results were reported:
• Symptomatic intracerebral haemorrhage occurred in 5.6% of patients treated with tissue plasminogen activator and asymptomatic intracerebral haemorrhage occurred in 17.3% of patients.
• In multivariable analysis, symptomatic intracerebral haemorrhage was increased with baseline antiplatelet use (single antiplatelet: OR, 2.04, 95% CI, 1.07 to 3.87, P=0.03; double antiplatelet: OR, 9.29, 3.28 to 26.32, P<0.001), higher National Institutes of Health Stroke Scale score (OR, 1.09 per point, 1.03 to 1.15, P=0.002), and CT changes defined by ASPECTS (ASPECTS 8 to 9: OR, 2.26, 0.63 to 8.10, P=0.21; ASPECTS < or =7: OR, 5.63, 1.66 to 19.10, P=0.006).
• Higher National Institutes of Health Stroke Scale was associated with decreased odds of good clinical outcome (OR, 0.82 per point, 0.79 to 0.85, P<0.001).
• There was no relationship between baseline antiplatelet use or CT changes and clinical outcome.
The authors comment that given the lack of an association between prior use of antiplatelet therapy and clinical outcome, their data do not support the withholding of thrombolytic treatment.