In an analysis that included nearly 1,300 patients with large-vessel ischaemic stroke, earlier treatment with endovascular thrombectomy (intra-arterial use of a micro-catheter or other device to remove a blood clot) plus medical therapy (use of a clot dissolving agent) compared with medical therapy alone was associated with less disability at three months, according to a study appearing in the 27 September issue of JAMA.
Five randomised trials have demonstrated the benefit of second-generation endovascular recanalization therapies over medical therapy alone among patients with acute ischaemic stroke due to large vessel occlusions. However, uncertainties remain about the benefit and risk of endovascular intervention when undertaken more than six hours after symptom onset. Michael D Hill, of the University of Calgary, Calgary, Canada, and colleagues conducted a meta-analysis of the data from these five randomized trials (1,287 patients enrolled at 89 international sites). Demographic, clinical, and brain imaging data as well as functional and radiologic outcomes were pooled.
The researchers found that compared with medical therapy alone, earlier treatment with endovascular thrombectomy plus medical therapy was associated with lower degrees of disability at three months. Benefit was greatest with time from symptom onset to arterial puncture for thrombectomy of less than two hours and became nonsignificant after 7.3 hours.
Among 390 patients who achieved substantial reperfusion with endovascular thrombectomy, each one-hour delay to reperfusion was associated with a less favourable degree of disability and less functional independence, but no change in mortality.
The authors note that within 7.3 hours, “functional outcomes were better the sooner after symptom onset that endovascular reperfusion was achieved, emphasising the importance of programmes to enhance patient awareness, out-of-hospital care, and in-hospital management to shorten symptom onset-to-treatment times.”
“The results of this study reinforce guideline recommendations to pursue endovascular treatment when arterial puncture can be initiated within six hours of symptom onset, and provide evidence that potentially supports strengthening of recommendations for treatment from six through 7.3 hours after symptom onset.”