NEW ORLEANS—Thrombolysis may be safe and effective in patients with wake-up stroke whose clinical and imaging characteristics are similar to those of patients who present with stroke within 4.5 hours of onset, according to a study presented at the 2012 International Stroke Conference.
Dulka Manawadu, MD, Stroke and General Medicine Consultant at King’s College Hospital in London, and colleagues selected 394 participants from a registry of thrombolyzed patients for a retrospective analysis. The population included 326 patients thrombolyzed within 4.5 hours of stroke onset and 68 patients with wake-up stroke. Eligible patients had an NIH Stroke Scale (NIHSS) score of at least 5, and their age, sex, modified Rankin Scale (mRS) score, vascular risk factors, and stroke etiology were recorded.
The outcome measures of the analysis were NIHSS score after 24 hours, and mRS score, intracerebral hemorrhage, and death after three months. The team tried to minimize its bias by having outcomes evaluated by trained investigators who were unaware of the allocation of the patients.
Baseline characteristics were similar for patients in both groups. Patients’ mean age was about 73, and about 45% were male. About 58% of all patients had hypertension, and the mean systolic blood pressure was approximately 150. Patients’ mean NIHSS score was about 13, and the majority of strokes were cardioembolic for both groups of patients.
Thrombolysis Reduces Disability in Patients With Wake-Up Stroke
The investigators found that the two groups of patients experienced similar outcomes. After three months, 37% of patients with wake-up stroke had an mRS score between 0 and 2, compared with 38% of the patients who received thrombolysis within 4.5 hours of stroke onset. The mortality rate after three months was 15% for patients with wake-up stroke, compared with 26% for the other patients, but the difference could result from selection bias, said Dr. Manawadu. Approximately 22% of patients with wake-up stroke experienced intracerebral hemorrhage, compared with 20% of the other patients.
To obtain results that closely represented conventional thrombolysis practice, the investigators reanalyzed the data, excluding patients younger than 18 and older than 80. Again, outcomes were similar for both groups, but with a few differences. At 24 hours, the mean NIHSS score for wake-up stroke patients was 5.3, compared with 8.9 for those who received thrombolysis within 4.5 hours of stroke onset. Mortality after three months was 3% for patients with wake-up stroke, compared with 18% for the other patients. In addition, 58% of patients with wake-up stroke had mRS scores between 0 and 2 after three months, compared with 51% of other patients.
Further Research Could Yield New Standards for Stroke Treatment
Although the results are based on a single-center retrospective study, Dr. Manawadu noted that the trial included all consecutive patients who presented with stroke, and the investigators were able to collect 98% of all follow-up data at three months.
“Our study shows treating wake-up stroke patients is safe,” said Dr. Manawadu. “I think the time is now right to prospectively randomize these patients with wake-up strokes into thrombolysis trials,” she concluded.
—Erik Greb
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