Validation assessment of risk scores to predict postthrombolysis intracerebral haemorrhage

Background Two clinical risk scores, the Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores, have been proposed to predict the risk of intracerebral haemorrhage following thrombolysis in acute ischaemic stroke. Aims To validate Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores as predictors of post-tissue plasminogen activator symptomatic intracerebral haemorrhage and asymptomatic intracerebral haemorrhage in an independent cohort. Methods Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores were calculated for the cohort of tissue plasminogen activator-treated patients enrolled in the placebo arms of the SAINT-I and SAINT-II trials. The absolute risk of symptomatic intracerebral haemorrhage and asymptomatic intracerebral haemorrhage associated with each scoring system was determined. The overall predictive value was assessed using c-statistics. Results Symptomatic intracerebral haemorrhage occurred in 5·6% of 965 patients treated with tissue plasminogen activator in the SAINT cohorts. The risk of symptomatic intracerebral haemorrhage was modestly greater, with higher Haemorrhage After Thrombolysis scores (0: 4·1%, 1: 4·1%, 2: 8·8%, 3: 12·5%, 4: 0%, 5: no subjects). Similar results were seen with the Multicentre Stroke Survey score (0: 0%, 1: 4·8%, 2: 2·3%, 3: 7·3%, 4: 6·3%). In logistic regression, the Haemorrhage After Thrombolysis score was associated with the risk of symptomatic intracerebral haemorrhage (odds ratio=1·41 per point, 95% confidence interval: 1·05-1·89, P=0·021) and asymptomatic intracerebral haemorrhage (odds ratio=1·59 per point, 95% confidence interval: 1·33-1·92, P<0·001). The Multicentre Stroke Survey score was modestly associated with the risk of symptomatic intracerebral haemorrhage (odds ratio=1·43 per point, 95% confidence interval: 0·95-2·15, P=0·084) and asymptomatic intracerebral haemorrhage (odds ratio=1·63 per point, 95% confidence interval: 1·27-2·08, P<0·001). The c-statistic was 0·59 for predicting symptomatic intracerebral haemorrhage and 0·61 for asymptomatic intracerebral haemorrhage for both the Haemorrhage After Thrombolysis and the Multicentre Stroke Survey scores. Conclusions While both the Haemorrhage After Thrombolysis and Multicentre Stroke Survey scores were associated with a risk of symptomatic intracerebral haemorrhage, discriminatory ability was limited.