Tenecteplase Before EVT: Is There a Benefit in Late BAO?

Adding intravenous (IV) tenecteplase before endovascular thrombectomy (EVT) did not improve functional outcomes in patients with basilar artery occlusion (BAO) who presented for treatment 4.5-24 hours after the onset of stroke, new research showed.The multicenter, open-label, randomized controlled trial also revealed that rates of 90-day mortality and symptomatic intracranial hemorrhage weren’t significantly different between those who received thrombolysis and those that didn’t.“Our findings suggest that for patients with BAO who can undergo EVT in the late time window, giving tenecteplase first does not appear to provide an additional functional benefit,” study author Wei Hu, MD, PhD, Department of Neurology, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, USTC, Hefei, China, told Medscape Medical News.“These results may help clinicians make treatment decisions in this specific setting,” Hu added.The findings were published online on September 23 in JAMA.Unanswered QuestionEVT is standard care for patients with BAO, an uncommon but devastating form of posterior-circulation ischemic stroke. But while IV thrombolysis is recommended within 4.5 hours of the stroke, whether adding it before EVT in the extended window improves outcomes among patients with BAO remains an open question.Some trials have shown benefits to this approach; others haven’t. But Hu noted that previous evidence on tenecteplase before EVT has come mainly from earlier treatment windows or from patients with anterior-circulation strokes.The ATTENTION LATE trial included 330 adults (mean age, 66 years; 74% male) with moderate-to-severe BAO admitted to one of 40 EVT-capable centers in China within 4.5-24 hours of stroke onset.Participants either received IV tenecteplase followed by EVT (intervention; n = 166) or EVT alone (control group; n = 164). Baseline characteristics were similar between groups, including median posterior circulation Acute Stroke Prognosis Early CT Score, National Institutes of Health Stroke Scale (NIHSS) score, interval from estimated BAO to randomization, and time from stroke onset to reperfusion. The mean age in the control group was older than the intervention group (67 vs 65 years).The most common cause of stroke in both groups was large artery atherosclerosis (about 70%), followed by cardioembolism (about 22%). The most common BAO sites were proximal basilar artery, mid-basilar artery, and distal basilar artery.Investigators performed follow-up scans within 72 hours of randomization to evaluate recanalization and infarct size and assess for intracranial hemorrhage. Blinded personnel conducted 3-month follow-up telephone interviews.The primary outcome was functional independence, defined as a 90-day modified Rankin Scale (mRS) score of 0-2 (scores range from 0 for no symptoms to 6 for death).Individualized Treatment KeyResearchers found no significant between-group difference in the primary outcome. A 90-day mRS score of 0-2 was achieved by 30.3% in the intervention group vs 30.5% with EVT alone (adjusted rate ratio [aRR], 0.92; 95% CI, 0.67-1.25).As for secondary outcomes, a 90-day mRS score of 0-3 (good outcome) was attained by 40% in the intervention group vs 39.6% in the control group. The median 24-hour NIHSS score was 24 in the intervention group vs 22 in the control group. Rates of successful reperfusion after EVT were also similar between groups: 95.8% in the intervention group vs 94.5% in the control group.The two groups had comparable 90-day mortality rates (40% with intervention vs 42.7% in the control group; aRR, 0.98; 95% CI, 0.77-1.26). Symptomatic intracranial hemorrhage within 72 hours was observed in 5.1% in the intervention group vs 4.0% in the control group (aRR, 1.22; 95% CI, 0.43-3.43).Hu stressed the new results apply only to the late-window study population and may not apply to earlier presentations or to patients who face substantial delays before EVT. “Treatment decisions should remain individualized,” Hu said.Guideline VariationsGuidelines on the use of IV thrombolysis pre-EVT in BAO appear somewhat inconsistent. The 2026 American Heart Association/American Stroke Association (AHA/ASA) guideline does not provide a BAO-specific recommendation to routinely administer IV thrombolysis beyond the conventional 4.5-hour window.On the other hand, the European guideline suggests IV thrombolysis for selected patients with BAO up to 24 hours, provided there are no contraindications other than time and no extensive posterior-circulation ischemic changes, said Hu. “Importantly, however, this is based on expert consensus rather than BAO-specific randomized evidence.”While the new findings “provide useful evidence for future guideline discussions,” changes to stroke guidelines would likely consider “the full body of evidence, including studies in other time windows and patient groups,” said Hu.“Our trial should be viewed as an important contribution to that process rather than the sole basis for changing recommendations,” Hu added.The high proportion of large-artery atherosclerosis in this Chinese cohort may limit the generalizability of results to other racial or ethnic groups, and the trial was open label, potentially introducing bias. As well, enrollment of patients with moderate-to-severe stroke limits generalizability to patients with mild BAO (NIHSS < 10), and the findings may not apply to patients presenting to centers not capable of EVT.The new study aligns with previous research showing use of thrombolytics for anterior circulation strokes within the earliest time window (4.5 hours), or the so-called “bridging” before EVT, is “actually favorable,” but there’s no benefit “for those who are going to rapid endovascular therapy,” said Shyam Prabhakaran, MD, professor, Department of Neurology, UChicago Medicine, Chicago, who chaired the writing group for the 2026 AHA/ASA stroke guideline.“You give IV thrombolysis if you’re in the 4.5-hour window, but if you’re in the 4.5- to 24-hour window and the patient is going to go for endovascular therapy, you don’t need to give that drug,” Prabhakaran told Medscape Medical News. “However, if you think there’s going to be a delay for endovascular therapy or the patient is not a candidate for that therapy, it’s reasonable to give it.”Not Completely GeneralizableThe new study “is not completely generalizable” to US patients because of population and treatment differences, said Prabhakaran. For example, the current study population “had a lot of atherosclerosis of the arteries versus a blocked artery from a clot from the heart, which is more typical in Western populations.”As well, he added, “this group got stenting quite a bit and we wouldn’t do that here as a standard treatment.”He also noted that some US patients with stroke had to be transferred between centers to receive thrombolytics and then EVT, which impacts timing.Asked why the US guideline differs from the European one, Prabhakaran said experts on his committee “did not feel there was enough evidence to extend the use of thrombolysis to 24 hours in basilar artery occlusion patients.”The study was supported by grants from the Fundamental Research Funds for the Central Universities and from the Clinical and Translational Research Project of Anhui Province. CSPC Recomgen Pharmaceutical (Guangzhou) provided the tenecteplase. Study authors’ disclosures are included in the original article. Prabhakaran reported having no conflicts of interest relevant to this study.