NEW ORLEANS – Two new risk assessment scores predicted the likelihood of a symptomatic intracranial hemorrhage after ischemic stroke treatment with more than 70% accuracy.
Predictive rules such as these are important because there is still no large-scale prospective study that clearly identifies which patients with ischemic stroke are more likely to develop a brain bleed after treatment with intravenous tissue plasminogen activator (TPA), Dr. Bijoy Menon said at the International Stroke Conference.
Dr. Menon, a clinical stroke fellow at the University of Calgary (Alta.), and his colleagues developed a 101-point score based on data extracted from the Get With The Guidelines stroke cohort. The cohort consisted of 10,242 patients with ischemic stroke who received TPA within 3 hours of the onset of stroke symptoms. A derivation cohort comprised 70% of the group; the rule was then validated in the remaining 30%.
The cohort’s mean age was 69 years. All patients experienced a moderate to severe ischemic stroke, with a mean National Institutes of Health Stroke Scale (NIHSS) score of 11. They received TPA at a mean of 1.35 hours after symptom onset.
About 5% of the group (496 patients) experienced a symptomatic intracranial hemorrhage (ICH), which the investigators defined as neurologic worsening within 36 hours of TPA administration.
In a multivariate regression model, Dr. Menon and his coinvestigators found six patient characteristics that were significantly associated with a brain bleed. They assigned each of these characteristics a point spread based on the range of measurements:
• Age. From age 60 years or younger (8 points) to older than 80 (17 points).
• NIHSS score. From 1-5 (25 points) to 20 and over (42 points).
• Systolic blood pressure. From less than 120 mm Hg (10 points) to 180 mm Hg or higher (21 points).
• Blood glucose level. From less than 100 mg/dL (2 points) to 150 mg/dL or more (8 points).
• Ethnicity. Asian, 9 points; all others, 0 points.
• Gender. Male, 4 points; female, 0 points.
Diabetes and a history of stroke were significantly associated with ICH in the initial analysis, but the P values were nonsignificant in the multivariate analysis, Dr. Menon noted.
"We also did not find any significantly increased risk associated with warfarin use or with the baseline international normalized ratio," he said at the meeting, sponsored by the American Heart Association.
The score accurately predicted ICH in 71% of the validation cohort, "comparable to most of the other scoring methods out there."
While the score is "well validated and evidence based," neither it nor any other single measure should be the sole factor in determining ischemic stroke treatment, Dr. Menon emphasized. "This is very important. It should not be used to infer which patients would benefit most or least from IV TPA. This is a cohort study, and because treatment was at the discretion of the individual physicians, there may be a selection bias present in it."