Analysis of revascularisation in ischaemic stroke with EmboTrap (ARISE I study) and meta-analysis of thrombectomy

Abstract

Background and purpose: The goal of the analysis of revascularisation in ischaemic stroke with EmboTrap study (ARISE I) was to demonstrate the effectiveness of EmboTrap.

Methods: ARISE I was an open label, single arm, multicentre, prospective study for the treatment of acute stroke due to large vessel occlusion. The primary outcome was revascularisation of the target vessel as measured by the modified thrombolysis in cerebrovascular infarction (mTICI) score of at least 2b following thrombectomy with EmboTrap. For comparison of the ARISE I results a meta-analysis of eight randomised controlled trials was performed.

Results: ARISE I enrolled 40 patients. Their baseline characteristics that are predictors of stroke outcome and procedure timings in ARISE I were similar to those reported in recent randomised controlled trials. The primary outcome, good revascularisation rates (mTICI 2b/3 scores) after three or fewer passes with EmboTrap were 75% (95% confidence interval (CI) 62-88%), which is the same as 74% found in randomised controlled trials (difference of 0.8%, P = 0.95). After additional EmboTrap passes or the use of another device mTICI 2b/3 scores rose to 85% (95% CI 74-96%), which was also similar to the randomised controlled trials (difference 11%, P = 0.38). The high revascularisation rates in ARISE I converted into 64% good clinical outcomes (modified Rankin scale ≤2) compared to 50% in randomised controlled trials (difference 14%; 95% CI -13.7-41.7%; P = 0.32).

Conclusions: ARISE I demonstrates that thrombectomy using the EmboTrap stent retriever yields similar results to devices that were used in recent randomised controlled trials for the treatment of stroke due to large vessel occlusions. ClinicalTrials.gov identifier NCT02190552.

Keywords: Ischaemic stroke; mechanical thrombectomy; meta-analysis; stent retriever.

Figures

Figure 1.

(a) The primary outcome of good revascularisation as measured by a modified thrombolysis in cerebrovascular infarction (mTICI) 2b/3 score within three or fewer passes with EmboTrap. The proportion of patients with previous intravenous thrombolysis was the same in ARISE I and the randomised controlled trials. ARISE40 designates the 40 ARISE I patients. (b) The rate of mTICI 2b/3, if after three passes additional rescue therapy procedures were used. ARISE40 designates the 40 ARISE I patients (see also Supplementary Figure 1).

Figure 2.

Direct comparison of a good clinical outcome (modified Rankin scale ≤ 2) between ARISE I and the mechanical thrombectomy arms of previous randomised controlled trials. The similar and numerically (but not significantly) more positive performance of the ARISE I procedure is visually obvious. ARISE40 designates the 40 ARISE I patients (see also Supplementary Figure 2).

Figure 3.

Good clinical outcome (modified Rankin scale ≤ 2) at 90 days after mechanical thrombectomy, with or without prior intravenous thrombolysis, compared to best medical treatment for previous randomised controlled trials. Direct comparison using the log relative risk. Values higher than zero indicate a beneficial effect of mechanical thrombectomy.