Tirofiban Associated With Higher Likelihood of Excellent Poststroke Outcome Than Aspirin
Although treatment with tirofiban improved the odds of excellent outcome, results for the secondary end points did not consistently support the primary end point analysis.
Among patients with acute ischemic stroke without large or medium-sized vessel occlusion who were not eligible for reperfusion therapy or whose symptoms progressed after thrombolysis, treatment with intravenous tirofiban resulted in a greater likelihood of an excellent outcome at 90 days than oral aspirin. Published in the New England Journal of Medicine, the incidence of symptomatic intracranial hemorrhage (ICH) was low in both groups but slightly higher with tirofiban.
Otherwise known as RESCUE BT2 trial (ChiCTR2000029502), the analysis included 606 patients assigned to tirofiban and 571 to aspirin alone, with the primary efficacy end point of excellent outcome, defined as score of 0 or 1 on the modified Rankin Scale (mRS). Eligible patients had any of the 4 clinical presentations: ineligible for thrombolysis or thrombectomy and within 24 hours after last known to be well; progression of stroke symptoms 24 to 96 hours after onset; early neurologic deterioration after thrombolysis; or thrombolysis with no improvement at 4 to 24 hours.
Tirofiban is a fasting-acting, highly selective, low-molecular-weight nonpeptide glycoprotein 2b/3a receptor inhibitor with a short half-life that allows bleeding time to revert to normal within approximately 3 hours after its administration is stopped. Led by senior investigator Yang Qingwu, MD, PhD, director of the Department of Neurology at Xinqiao Hospital, patients received intravenous tirofiban at a dose of 0.4 ug per kilogram of body weight per minute for 30 minutes, followed by a continuous infusion of 0.1 ug per kilogram per minute for up to 48 hours.
Patients in the tirofiban group also received oral placebo daily for 2 days. Those assigned to aspirin also received intravenous placebo and oral aspirin (100 mg per day) for 2 days. Beginning approximately at the 44th hour after administration of intravenous tirofiban or placebo, all the patients received oral aspirin at a dose of 100 mg per day until day 90.
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Conducted from October 2020 to June 2022, excellent outcomes of 0 or 1 on mRS occurred in 29.1% of patients on tirofiban and 22.2% of those on aspirin (adjusted risk ratio, 1.26; 95% CI< 1.04-1.53; P = .02). For the first secondary end point of favorable outcome, indicated by scores of 0 to 2 on mRS, the adjusted common OR when comparing the groups was 1.38 (95% CI, 1.07-1.78; P = .01) favoring tirofiban.
In the tirofiban and aspirin groups, investigators observed median mRS scores of 2 (IQR, 1-3) and 2 (IQR, 2-3), respectively. Because this tests in the secondary-end point gatekeeping sequence did not meet the prespecified threshold for statistical significance, results for this end point and all subsequent secondary end points were considered not significant different between groups.
In terms of safety, death occurred in 3.8% (n = 23) of patients in the tirofiban group and in 2.6% of patients on aspirin (adjusted RR, 1.62; 95% CI, 0.88-2.95; P = .12). Notably, symptomatic ICH occurred in 6 patients (1%) in the tirofiban group and none in the aspirin group. Follow up imaging with either computed tomography or diffusion-weighted imaging was done in 38.8% and 46.2% of patients in the tirofiban group vs 32.7% and 47.5% of those on aspirin.
