Scoring system use before rtPA predicts 3-month stroke outcomes

27 August 2010

MedWire News: Using a scoring system based on diffusion-weighted imaging (DWI) before intravenous (IV) recombinant tissue-type plasminogen activator (rt-PA) therapy can predict 3-month functional and vital outcomes in stroke patients, Japanese researchers report.

Determining the Alberta Stroke Programme Early CT Score (ASPECTS) using DWI also independently predicted symptomatic intracerebral hemorrhage (ICH) within 36 hours of rt-PA administration.

“Pretreatment magnetic resonance imaging with DWI provides valuable information for predicting clinical outcome after intravenous rt-PA therapy,” say Kazunori Toyoda (National Cerebral and Cardiovascular Center, Osaka) and colleagues.

The team retrospectively studied 477 consecutively recruited stroke patients, with a mean age of 71 years, treated with 0.6 mg/kg alteplase at one of 10 stroke centers in Japan between October 2005 and July 2008.

Participants had a median National Institutes of Health Stroke Scale score of 13 and a median ASPECTS on DWI of eight just before rt-PA therapy. Symptomatic ICH was identified in 3.1% of the group.

At 3 months, 51.4% of patients were independent, identified as a modified Rankin Scale (mRS) score of between zero and two, and 6.1% had died.

Individuals deemed independent had a significantly higher median ASPECTS than others, at nine versus eight, respectively.

An ASPECTS of at least seven optimally predicted independence defined on the mRS, according to receiver operating characteristic curves. In multivariate regression analysis, this related to independence on the mRS, with an odds ratio (OR) of 1.85.

An ASPECTS of four or less was associated with death, with an OR of 3.61, while an ASPECTS of five or less was associated with symptomatic ICH, with an OR of 4.74.

“Although clinical use of rt-PA should not be chosen solely using DWI-ASPECTS because it requires consideration of various underlying conditions, patients with DWI-ASPECTS of four or less do not seem to be good candidates for IV rt-PA since most patients with these scores have fatal or dependent outcomes,” Toyoda et al report in the journal Neurology.

“DWI-ASPECTS of five may be another warning sign for choosing rt-PA since more than 10% of patients with this score developed symptomatic intracerebral hemorrhage.”

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Neurology 2010; 75: 555–561