Intensive BP control harmful after endovascular thrombectomy for acute ischemic stroke
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In patients who had endovascular thrombectomy for acute ischemic stroke with large-vessel occlusion, intensive systolic BP control to less than 120 mm Hg was linked with poor outcomes after the procedure, researchers reported.
“Our study provides a strong indication that this increasingly common treatment strategy should now be avoided in clinical practice,” Craig S. Anderson, MBBS, PhD, director of global brain health at The George Institute for Global Health in Newtown, New South Wales, Australia, said in a press release.
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Anderson and colleagues conducted the ENCHANTED2/MT open-label randomized trial at 44 centers in China to determine the safety and efficacy of more-intensive vs. less-intensive BP control strategies after endovascular thrombectomy for acute ischemic stroke with large-vessel occlusion. The findings were presented at the World Stroke Congress and published in The Lancet.
The researchers randomly assigned 821 patients who had systolic BP of at least 140 mm Hg for more than 10 minutes after successful endovascular thrombectomy for acute ischemic stroke with large-vessel occlusion (mean age, 67 years; 38% women), to more-intensive treatment targeting systolic BP < 120 mm Hg or less-intensive treatment targeting systolic BP 140 to 180 mm Hg, to be achieved after 1 hour and sustained for at least 72 hours.
“A potential downside of this now widely used and effective treatment is that the rapid return of blood supply to an area that has been deprived of oxygen for a while can cause tissue damage known as reperfusion injury,” Anderson said in the release. “This has resulted in a shift in medical practice towards more intensive lowering of blood pressure after clot removal to try and minimize this damage, but without evidence to support the benefits vs. potential harms.”
The trial was stopped in June for safety and efficacy concerns after a review of the outcome data, according to the researchers.
The primary outcome, poor functional outcome as determined by modified Rankin Scale score at 90 days, occurred more often in the more-intensive group than in the less-intensive group (common OR = 1.37; 95% CI, 1.07-1.76), Anderson and colleagues found.
At 90 days, compared with the less-intensive group, the more-intensive group had more early neurological deterioration (common OR = 1.53; 95% CI, 1.18-1.97) and major disability (common OR = 2.07; 95% CI, 1.47-2.93), according to the researchers.
There were no differences between the groups in symptomatic intracranial hemorrhage, serious adverse events or mortality.
“While our study has now shown intensive blood pressure control to a systolic target of less than 120 mm Hg to be harmful, the optimal level of control is yet to be defined,” Anderson said in the release.
References:
- Large stroke trial finds intensive blood pressure lowering after clot removal worsens recovery. www.eurekalert.org/news-releases/969331. Published Oct. 28, 2022. Accessed Oct. 28, 2022.
- Yang P, et al. Lancet. 2022;doi:10.1016/S1040-6726(22)01882-7.
Perspective
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Larry B. Goldstein, MD, FAAN, FANA, FAHA
The optimal BP target after endovascular thrombectomy for large-vessel occlusion ischemic stroke is uncertain, leading to variations in practice. This open-label, blinded-endpoint, randomized controlled trial was conducted at 44 tertiary-level hospitals in China and randomly assigned patients who had elevated systolic BP (≥1 40 mm Hg for > 10 minutes) following successful reperfusion with endovascular thrombectomy to a more intensive target (systolic BP < 120 mm Hg) or a less intensive target (systolic BP 140 to 180 mm Hg) within 1 hour and maintained for 72 hours. The achieved mean systolic BP was 125 mm Hg at 1 hour and 121 mm Hg at 24 hours in the more-intensive group and 143 mm Hg at 1 hour and 139 mm Hg at 24 hours in the less-intensive group. Death and neurologcial worsening were greater in the more-intensive group at 7-days (OR = 1.53; 95% CI, 1.18-1.97). Death or disability were also higher at 90 days in the more-intensive group (53% of 404 patients vs. 39% of 406 patients; OR 1.85; 95% CI 1.36–2.51; P = .0001). There was no difference in hemorrhagic complications.
The study appears to have been well-designed and well-conducted. The intended sample size was 2,257 for a 90% power to detect an OR of 0.77 for worse outcome at 90 days. The study was stopped after 810 participants were enrolled.
This study suggests that a more permissive strategy (ie, systolic BP 140 to 180 mm Hg) is preferable to a lower BP target in patients with systolic BP > 140 mm Hg after successful thrombectomy for large-vessel occlusion. The study was conducted in a Chinese population and needs to be confirmed in other populations to assess the generalizability of the results.
The study was not designed to test a mechanistic hypothesis. I could speculate that despite angiographic reperfusion, cerebral autoregulation is impaired in the area of ischemic injury with cerebral blood flow to more marginally reperfused areas more susceptible to decreased systemic BP. This might also be affected by the integrity of collaterals to the ischemic tissue.
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Anderson CS, et al. Plenary 03. Presented at: World Stroke Congress; Oct. 26-29, 2022; Singapore.
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