Twelve-Month Follow-Up of t-PA Treated Patients

Abstract & Commentary

Source: Kwiatkowski TG, et al. Effects of tissue plasminogen activator for acute ischemic stroke at one year. N Engl J Med 1999;340:1781-1787.

The ninds recombinant tissue plasminogen activator (t-PA) Stroke Study (The NINDS rt-PA stroke study group. N Engl J Med 1995;333:1581-1587) found that patients treated with t-PA within three hours after the onset of acute stroke symptoms were 30% more likely than placebo controls to have minimal or no disability three months later. Mortality at three months among t-PA patients (17%) was similar to that of controls (21%), despite the higher frequency of symptomatic intracerebral hemorrhage (6%, 50% fatal) in the t-PA group.

The present study confirmed that the magnitude of benefit (30% with an absolute increase in favorable outcome of 11-13%) persisted in the t-PA-treated group at six and 12 months. No significant difference in mortality affected treated (24%) vs. control patients (28%; P = 0.29). There was no detectable association between the type of stroke identified at baseline and 12-month outcome. The rate of recurrent stroke at 12 months was 5% in both groups.

Commentary

This follow-up study validates the valuable effect imposed by thrombolytic therapy with t-PA given within three hours after stroke onset both immediately and permanently. The results contrast with the negative or equivocal findings of European trials of thrombolytic agents given up to six hours after the onset of stroke symptoms (MAST-I Group. Lancet 1995;346:1509-1514; The Multi-Center Acute Stroke Trial—European Study Group. N Engl J Med 1996;335:145-150; Hacke W, et al. Lancet 1998;352:1245-1251).

Kwiatkowski and associates found that t-PA benefitted all subgroups of ischemic strokes. Consequently, they again advise against selection of patients for t-PA treatment based on the presumed mechanism of stroke. In addition, certain variables such as younger age, lower NIH stroke score, and absence of diabetes at baseline were associated with a favorable outcome and survival at 12 months. Since none of these variables interacted with treatment, they should not influence selection of patients for t-PA treatment.

Thrombolytic treatment with t-PA remains the first-line therapy for acute ischemic stroke patients regardless of stroke subtype. —jjc

At baseline, which of the following can be used to select patients for t-PA treatment?

a. Absence of diabetes mellitus

b. Age younger than 55 years

c. Embolic stroke

d. Atherothrombotic stroke

e. None of the above