International
Stroke Conference 2012
NEW ORLEANS — Thrombolysis with clot-busting drugs may be safe for
patients who wake up experiencing stroke symptoms, according to preliminary
data presented at the American Stroke Association’s International Stroke
Conference.
“The easy answer [as to why patients with
wake-up stroke are excluded from treatment] is that there is
no evidence, so you don’t know the risk–benefit ratio,” Dulka
Manawadu, MD, stroke medical consultant at King’s College Hospital,
London, U.K., said during a press conference. However, results from some
studies show that wake-up stroke patients, who do not receive thrombolysis, have poorer
outcomes than those with other types of stroke.
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Dulka Manawadu
Courtesy
of the American Heart Association
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Using registry data, the researchers compared clot-busting therapy with
alteplase (Activase, Genentech) received by 326 patients within 4.5 hours of
symptom onset and 68 wake-up stroke patients with unknown symptom onset.
Wake-up stroke patients received clot-busting treatments if their clinical
presentation and early stroke changes in CT scan images were comparable to
those treated with a known time of onset. All patients received treatment in
the same London medical center. Researchers did not randomly assign patients to
receive different treatments for comparison, according to the press release.
Both groups had similar BP,
blood glucose levels and NIH Stroke Scale scores. Although
the two groups were comparable for mean age and vascular risks, more women
experienced wake-up strokes (66% vs. 52%).
CT perfusion was performed in 26% of patients within 4.5 hours and 67%
of wake-up stroke patients (P<.0001). Door-to-needle time was 59
minutes and 73 minutes, respectively (P=.11). The researchers observed
no differences in mean NIH Stroke Score at 24 hours (9.2 vs. 8.1), intracranial
hemorrhage (17% vs. 22%), symptomatic intracranial hemorrhage (2.5% vs. 2.9%)
and premorbid Rankin Score of 0 to 2 at 3 months (49% vs. 37%) between patients
treated within 4.5 hours and wake-up stroke patients.
At 3 months, mortality was lower in thrombolysed wake-up stroke patients
(15% vs. 24%; P=.063); this finding became significant after researchers
adjusted for covariates in multiple regression (P=.024).
Doctors may be reluctant to give clot-busting drugs to patients in whom
the time of stroke onset is not known because the risks for bleeding are not
known, Manawadu said. However, a significant proportion of patients who have
stroke symptoms upon waking may have suffered stroke in the early hours of the
morning and may still be within the window of time when clot-busting treatments
are known to be effective.
“According to this study, thrombolizing wake-up stroke patients is
feasible and safe,” Manawadu said. “I think the time is now right to
prospectively randomize these patients with wake-up stroke into trials of
thrombolysis.”
For more information:
Disclosure: Dr. Manawadu received institutional grants from Kings
College Hospital.
Wake-up strokes comprise about 14% of ischemic strokes presenting to EDs and a recent study estimated that 58,000 Americans present to an ED with a wake-up stroke every year. This is a key area of interest for researchers. The data on whether it is safe and effective to treat patients with wake-up strokes has been mixed thus far, and this study is a welcome addition to the literature. Some researchers are using advanced imaging techniques to try to identify those patients most likely to benefit from intervention. Carefully conducted, rigorous trials are crucial for determining whether there are patients with wake-up strokes who would benefit from intervention.
– Jason Mackey, MD
Assistant Professor of Clinical Neurology
Indiana University School of Medicine
Disclosure: Dr. Mackey reports no relevant financial disclosures.