The decision to use tissue plasminogen activator in stroke patients who meet the criteria is seldom clear-cut, and two studies published in the November issue of Stroke analyze outcomes in patients who did and did not receive tPA for stroke.
One study, led by Eric E. Smith, MD, FRCPC, of the department of neurology at Massachusetts General Hospital, found that some patients who did not receive tPA because their stroke symptoms were mild or improving still had unfavorable outcomes. In the other study, led by Götz Thomalla, MD, of Universitätsklinikum Hamburg-Eppendorf in Hamburg, Germany, found there was no clinical evidence to exclude very old ischemic stroke patients from tPA solely because of age.
Dr. Smith and colleagues analyzed 431 consecutive stroke discharges collected at their institution as part of the Paul Coverdell National Acute Stroke Registry Pilot Prototype and the Get with the Guidelines Stroke Pilot. They defined early rapid improvement as a four-point or greater improvement in National Institutes of Health Stroke Scale (NIHSS) score between the time of initial evaluation and the time of tPA decision and neurological worsening as a two-point or greater worsening in NIHSS score during the same time period.
In the study, 41 (58%) of 71 ischemic stroke patients with a symptom duration of less than three hours were not treated with tPA because they were “too good to treat,” that is, their symptoms were mild or improving. The Stroke Scale score was the only independent predictor of the decision to withhold tPA, the authors found.
There were 11 patients deemed too good to treat who could not be discharged home, and two of these patients died. After the decision to withhold treatment, seven too-good-to-treat patients had neurological worsening, four of whom had had early rapid improvement. Early rapid improvement seems to carry a risk of subsequent neurological worsening, as has been shown in clinical trials, the researchers found.
Dr. Thomalla's study was conducted in 228 acute ischemic stroke patients in three German stroke centers who were treated with intravenous tPA and compared outcome data from patients younger than 80 with that from patients 80 or older. Of the patients, 16 percent fit into the latter category.
While just 26.3 percent of patients in the older group had a favorable outcome, 46.8 percent in the younger group did. Mortality also was higher in older patients, at 21.1 percent, compared with 5.3 percent for younger patients. There was no difference in the rates of parenchymal hemorrhage or symptomatic intracerebral hemorrhage between the two groups.