Patients with a large core infarct benefit from thrombectomy

The results of the phase 3 SELECT2 trial demonstrated superior functional outcomes with endovascular thrombectomy (EVT) plus medical care compared with medical care only in stroke patients with a large core infarct. However, EVT was associated with vascular complications. Cerebral haemorrhages were infrequent in both groups.

SELECT2 (NCT03876457) was a prospective, randomised, open-label, phase 3 clinical trial with blinded outcome assessment [1,2]. As 31 sites from the USA, Canada, Europe, Australia, and New Zealand participated, a covariate adaptive randomisation allowed for balanced baseline characteristics. Imaging evaluation was standardised. Participants were selected based on the presence of a stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery. The median ischaemic-core volume was ~80 ml (ranging from ~60 to ~120 ml). The 352 participants were randomised 1:1 to EVT plus medical care (n=178) or medical care alone (n=174). The median age was 67 years, and 73% were women. The primary outcome was the modified Rankin Scale (mRS) score at 90 days.

Leading author Dr Amrou Sarraj (UH Cleveland Medical Center, OH, USA) said that about 81% of patients in the control group had very poor outcomes at 90 days. The thrombectomy group saw a shift towards a more favourable outcome (see Figure). Dr Sarraj: “This shift translated into a 60% higher chance of improving the outcome on the mRS by at least 1 point.” (Wilcoxon–Mann–Whitney measure of superiority: 0.60). At 90 days, the generalised odds for achieving a better outcome on the mRS after thrombectomy versus medical care alone was significantly higher: odds ratio 1.51 (95% CI 1.20–1.89; P<0.001). A key secondary outcome was functional independence, which was not expected to be high in this population. It was met by 20% of participants in the thrombectomy group and 7% in the medical-care group (relative risk [RR] 2.97; 95% CI 1.60–5.51); the number needed-to-treat (NNT) was 7.34. The percentage of participants with independent ambulation in the thrombectomy group was 38% versus 19% (RR 2.06; 95% CI 1.43–2.96; NNT 5.11).

Figure: Modified Rankin Scale score at 90 days [1]



WMW, Wilcoxon–Mann–Whitney; CI, confidence interval; GenOR, generalised odds ratio.

Symptomatic intra-cerebral haemorrhage was infrequent and did not increase with thrombectomy (0.6%) versus medical management (1.1%; RR 0.49; 95% CI 0.04–5.36). Mortality was similar in the 2 groups: 38% versus 42% (RR 0.91; 95% CI 0.71–1.18). Early neurological worsening was increased, potentially related to infarct oedema. In the thrombectomy group, arterial access-site complications occurred in 5 participants, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11 participants. Dr Sarraj concluded that these complications did not distract from the overall benefit of thrombectomy in this study population.

1. Sarraj A. A randomized trial of endovascular thrombectomy versus medical management for ischemic stroke with a large core infarct on non-contrast CT or perfusion imaging. PL5.007, AAN 2023 Annual Meeting, 22–27 April, Boston, USA.
2. Sarraj A, et al. N Engl J Med. 2023;388(14):1259–71.

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Posted on 26 June 202328 March 2024