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.”
Dr. Daniel Strbian of the University of Helsinki presented a second score, dubbed SEDAN. Dr. Strbian and his colleagues developed their score based on a cohort of 972 ischemic stroke patients who developed an imaging-proven brain bleed after IV TPA treatment.
In a multivariate analysis, he and his associates found five factors that were independently associated with a significantly increased risk of symptomatic ICH: blood glucose level on admission, computed tomography (CT) imaging positive for ischemic stroke, cerebral artery hyperdensity, age, and NIHSS score.
Points were assigned based on the relative risk (RR) associated with each factor – the higher the total score, the greater the risk of symptomatic ICH. Each of the five risk-point categories generated a significant risk ratio:1 point, RR 0.19; 2 points, RR 0.40; 3 points, RR 1.85; 4 points, RR 3.7; 5 points, RR 5.6.
The score was validated in two additional groups totaling about 2,000 patients, resulting in an overall accuracy of about 77%.
“If we have a patient with a very high score, there is a very bad prognosis with a high chance of death or institutionalization at 3 months,” Dr. Strbian said. “In this case, we know that the patient may die if we do nothing, but perhaps the SEDAN [score] can help us determine if an endovascular approach might be better than thrombolysis.”
The SEDAN score is simple, easy, and quick to calculate, he said. But it’s only part of the treatment decision process.
“We can’t treat based on this score alone. If the patient fulfills the indications for TPA, it’s up to the physician and the patient to decide whether they are willing to accept the risk of an intracranial hemorrhage.”
Dr. Menon and Dr. Strbian reported having no financial conflicts.