Evidence is building that tenecteplase provides a reperfusion advantage over alteplase when used before thrombectomy in patients with basilar artery occlusion (BAO).
A retrospective study, led by Dr Fana Alemseged from the Royal Melbourne Hospital, comprised 110 patients with BAO from the EXTEND-IA TNK trials and the BATMAN registry.
Most (91) were treated with alteplase and only 19 with tenecteplase.
The study said substantial reperfusion (>50% or absence of retrievable thrombus) occurred in 26% of patients treated with tenecteplase versus 7% in patients treated with alteplase (RR 4.0, 95%CI 1.3-12; p=0.02), “obviating the need for IVT”.
In other outcomes, there were no differences observed between the treatment groups in parenchymal haematoma, symptomatic ICH or functional outcomes.
The study, published in Neurology, said there was uncertainty about the benefit of thrombectomy in BAO.
“Given this uncertainty, thrombolytic agents that may obviate the need for EVT or have beneficial effect during transfer to endovascular centers are warranted.”
Despite methodological limitations including the retrospective design and small number of patients treated with tenecteplase, the researchers said there were other factors suggesting their results may be a conservative estimate of the benefits of tenecteplase.
They added that RCTs to compare tenecteplase with alteplase in BAO patients were warranted given BAO patients’ dismal prognosis.
Dr Alemseged told the limbic that tenecteplase was recommended for stroke patients with large vessel occlusions, based on the results of the EXTEND-IA TNK trial.
“However, it was unclear whether this finding could be extrapolated to BAO as only six patients were included in this trial. Hence, the importance of this study,” he said.
He added that despite its rarity – 1% of all strokes and 10% of strokes with large vessel occlusion – BAO was one of the most devastating neurological conditions, associated with up to 70-80% disability and mortality if recanalisation does not occur.
“Sometimes, these patients present with non-specific (e.g. headache, vertigo, double vision) or fluctuating symptoms and deteriorate later on. Hence, it may be difficult to recognise this type of stroke early on and treatment is very time-critical in stroke.”
An accompanying editorial in the journal said tenecteplase was a promising alternative to alteplase for reasons including its relative ease of administration as a single IV bolus.
“The preferential use of tenectoplase for acute MI constitutes another consideration for hospitals with limited resources where stocking a single thrombolytic agent for both acute cardiovascular and acute cerebrovascular disease would reduce cost and complexity.”
And while still “not ready for prime time”, tenecteplase was “nearing a tipping point”.
“Given the advantages of cost, convenience and potential safety, some practitioners and patients may feel persuaded to use tenecteplase in place of alteplase, while others may justifiably wait for more evidence before they are convinced to do so; and may use tenecteplase in selected cases.”
However Dr Alemseged said he did not agree completely with the editorial.
“I think there is enough evidence of superiority of tenecteplase compared to alteplase in patients with large vessel occlusion. For sure, it would be good to have more evidence for patients with basilar artery occlusion, e.g. a RCT specifically designed for this population,” he said.