Elena Zapata-Arriaza, MD
Alemseged F, Ng FC, Williams C, Puetz V, Boulouis G, Kleinig TJ, Rocco A, Wu TY, Shah D, Arba F, et al. Tenecteplase vs Alteplase Before Endovascular Therapy in Basilar Artery Occlusion. Neurology. 2021;96:e1272-e1277.
There is growing evidence of the advantages of tenecteplase over alteplase in terms of reperfusion rates, ease of use, and speed of administration. However, this evidence comes from anterior territory ischemic strokes studies, and it is still unknown whether the benefits of tenecteplase can be superimposed on the posterior territory. In order to investigate the efficacy of tenecteplase (TNK) achieving better reperfusion than alteplase prior to endovascular therapy (EVT) in patients with basilar artery occlusion (BAO), Alemseged et al. performed a retrospective analysis of clinical and procedural data of consecutive BAO patients from the BATMAN registry and EXTEND-IA-TNK trial. Reperfusion >50% or absence of retrievable thrombus at the time of the initial angiogram was evaluated.
The authors included 110 BAO patients treated with intravenous thrombolysis prior to EVT. Nineteen patients were thrombolysed with TNK (0.25mg/kg or 0.40mg/kg) and 91 with alteplase (0.9mg/kg). Reperfusion>50% occurred in 26% of TNK patients vs 7% of alteplase group (RR 4.0 95%CI 1.3-12; p=0.02), despite shorter thrombolysis-to-arterial-puncture time in the TNK-treated patients vs alteplase-treated patients (48 vs 110 mins). No difference in symptomatic intracranial hemorrhage was observed (0% in TNK vs 1% in alteplase, p=0.9). Functional outcomes were not significantly different between treatment groups.
Currently, the only clinical trial that has shown benefit of endovascular treatment in the posterior territory is the BASIC Trial. However, this trial only demonstrates the efficacy of thrombectomy in BAO ischemic strokes with an NIHSS> 10, in a vascular territory in which the NIHSS does not reflect the severity of the occlusion as it does in the anterior territory. Therefore, the group of patients with basilar artery occlusion and NIHSS <10 can become considerable, and we do not have clear evidence of endovascular reperfusion therapy. While we find the way to the benefit of mechanical thrombectomy, intravenous fibrinolysis remains a useful and effective weapon in these patients. However, this pharmacological resource has expanded its arsenal, first with data in anterior circulation strokes, and we hope soon in posterior circulation stroke. Meanwhile, studies such as the one by Alemseged et al. show the way forward, especially when the pre-EVT reperfusion rate is higher in patients with TNK. Although the study has limitations and is not powerful enough to show benefits in functional outcome between subgroups, it would be logical to think that in future clinical trials, the best reperfusion rates with TNK could be associated with a good functional prognosis in patients with basilar artery occlusion.