ПрдолжениеIn this issue of Stroke, Kent et al7 developed a Stroke-Thrombolytic Predictive Instrument (TPI) to aid physicians considering thrombolysis for a patient with acute ischemic stroke. The authors used data from 5 major randomized clinical trials testing rt-PA in acute ischemic stroke. They developed logistic regression equations using clinical variables as potential predictors of a good outcome (defined as modified Rankin Scale score 1) and potential predictors of a catastrophic outcome (defined as modified Rankin Scale score 5) with and without use of rt-PA. To predict good outcome, the rt-PA treatment, age, diabetes, stroke severity, gender, prior stroke, systolic blood pressure, and time from symptom onset significantly affected prognosis. To predict catastrophic outcome, only age, stroke severity, and serum glucose significantly affected prognosis; rt-PA did not. The Stroke-TPI that was created is capable of predicting good and bad functional outcomes for acute ischemic stroke patients with and without thrombolysis.
Consider the following 2 acute ischemic stroke scenarios: In the first scenario, a 77-year-old woman with a history of diabetes mellitus presented to the emergency department relatively late in the course of her stroke symptoms. Her systolic blood pressure was 140 mm Hg, her serum glucose was 15.2 mmol/L, and her National Institute of Health Stroke Scale (NIHSS) score was low, only 5. By the time she had her intravenous lines placed, blood tests drawn and processed, and computed tomography of brain conducted and interpreted, the 3-hour window was nearly closed, at 179 minutes. The treating physician, patient, and accompanying family members had a critical decision to make and essentially no time in which to make it. The physician drew on traditionally available resources and clinical experience. In the National Institute of Neurological Disorders and Stroke (NINDS) rt-PA Stroke Study, on average, an acute ischemic stroke patient treated with rt-PA might expect an absolute risk reduction ranging from 11% to 15%, depending on the functional outcome scale.8 The physician attempted to balance that estimated treatment effect with the potential risk of harm from a symptomatic intracranial hemorrhage, quoted as 6.4%. The physician acknowledged that the later the treatment is administered, the lower the likelihood of a favorable outcome.9 A summary of postmarketing reports of rt-PA use in ischemic stroke has demonstrated that failure to adhere to indications and contraindications outlined in the guidelines, including time window, is associated with an increased risk of hemorrhagic complications.10 Finally, the treating physician’s common experience has been that there is invariably a good spontaneous recovery associated with a mild stroke, NIHSS score of 5, regardless of treatment.10 Ultimately, a decision was made to withhold rt-PA as the perceived risk outweighed the perceived benefit.
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