BACKGROUND AND PURPOSE: A long clot, defined by a low (0-6) clot burden score (CBS) assessed by T2*-MR sequence, is associated with worse clinical outcome after intravenous thrombolysis (IVT) for acute ischemic stroke than is a small clot (CBS, 7-10). The added benefit of mechanical thrombectomy (MT) might be higher in patients with long clot. The aim of this pre-specified post hoc analysis of the THRombectomie des Artères CErebrales (THRACE) trial was to assess the association between T2*-CBS, successful recanalization and clinical outcome. METHODS: Of 414 patients randomized in the THRACE trial, 281 patients were included in this analysis. Associations between T2*-CBS and clinical outcome on the modified Rankin Scale (mRS) at 3 months were tested. RESULTS: High T2*-CBS, i.e., small clot, was associated with a shift toward better outcome on the mRS; proportional odds ratio (POR) per point CBS was 1.19 (95% confidence interval [CI], 1.05 to 1.34) in the whole population, 1.34 (95% CI, 1.13 to 1.59) in IVT group, and 1.04 (95% CI, 0.87 to 1.23) in IVTMT group. After adjustment for baseline prognostic variables, the effect of the full scale T2*-CBS was not statistically significant in the whole population and for the IVTMT group but remains significant for the IVT group (POR, 1.32; 95% CI, 1.11 to 1.58). CONCLUSIONS: A small clot, as assessed using T2*-CBS, is associated with improved outcome and may be used as a prognostic marker. Despite the worst outcome with long clot, the relative benefit of MT over IVT seemed to increase with low T2*-CBS and longer clot.
Humans ; Magnetic Resonance Imaging ; Odds Ratio ; Stroke ; Thrombectomy ; Thrombosis

BACKGROUND AND PURPOSE: In the Aspiration vs. Stent Retriever for Successful Revascularization (ASTER) trial, which evaluated contact aspiration (CA) versus stent retriever (SR) use as first-line technique, the impact of the susceptibility vessel sign (SVS) on magnetic resonance imaging (MRI) was studied to determine its influence on trial results. METHODS: We included patients having undergone CA or SR for M1 or M2 occlusions, who were screened by MRI with T2* gradient recalled echo. Occlusions were classified as SVS (+) or SVS (–) in each randomization arm. Modified thrombolysis in cerebral infarction (mTICI) 2b, 2c, or 3 revascularization rates were recorded and clinical outcomes assessed by the overall distribution of modified Rankin scale (mRS) at 90 days. RESULTS: Among the 202 patients included, 143 patients were SVS (+) (70.8%; 95% confidence interval [CI], 64.5% to 77.1%). Overall, there was no difference in angiographic and clinical outcomes according to SVS status. However, compared to SR, CA achieved a lower mTICI 2c/3 rate in SVS (+) patients (risk ratio [RR] for CA vs. SR, 0.60; 95% CI, 0.51 to 0.71) but not in SVS (–) (RR, 1.11; 95% CI, 0.69 to 1.77; P for interaction=0.018). A significant heterogeneity in favor of superiority of first-line SR strategy in SVS (+) patients was also found regarding the overall mRS distribution (common odds ratio for CA vs. SR, 0.40 vs. 1.32; 95% CI, 0.21 to 0.74 in SVS (+) vs. 95% CI, 0.51 to 3.35 in SVS (–); P for interaction=0.038). CONCLUSIONS: As a first line strategy, SR achieved higher recanalization rates and a more favourable clinical outcome at 3 months compared to CA when MRI shows SVS within the thrombus.
Arm ; Cerebral Infarction ; Humans ; Magnetic Resonance Imaging ; Odds Ratio ; Population Characteristics ; Random Allocation ; Stents* ; Thrombectomy ; Thrombosis

On page 271, in Table 1, the value ‘1115 (65??51)’ of subgroup ‘Imaging to groin puncture’ and column heading ‘SVS (??’ was input incorrectly. The correct value is ‘115 (65??51).’

Background: and Purpose Patients with acute ischemic stroke, proximal vessel occlusion and a large ischemic core at presentation are commonly not considered for mechanical thrombectomy (MT). We tested the hypothesis that in patients with baseline large infarct cores, identification of remaining penumbral tissue using perfusion imaging would translate to better outcomes after MT.
Methods: This was a multicenter, retrospective, core lab adjudicated, cohort study of adult patients with proximal vessel occlusion, a large ischemic core volume (diffusion weighted imaging volume ≥70 mL), with pre-treatment magnetic resonance imaging perfusion, treated with MT (2015 to 2018) or medical care alone (controls; before 2015). Primary outcome measure was 3-month favorable outcome (defined as a modified Rankin Scale of 0–3). Core perfusion mismatch ratio (CPMR) was defined as the volume of critically hypo-perfused tissue (Tmax >6 seconds) divided by the core volume. Multivariable logistic regression models were used to determine factors that were independently associated with clinical outcomes. Outputs are displayed as adjusted odds ratio (aOR) and 95% confidence interval (CI).
Results: A total of 172 patients were included (MT n=130; Control n=42; mean age 69.0±15.4 years; 36% females). Mean core-volume and CPMR were 102.3±36.7 and 1.8±0.7 mL, respectively. As hypothesized, receiving MT was associated with increased probability of favorable outcome and functional independence, as CPMR increased, a difference becoming statistically significant above a mismatch-ratio of 1.72. Similarly, receiving MT was also associated with favorable outcome in the subgroup of 74 patients with CPMR >1.7 (aOR, 8.12; 95% CI, 1.24 to 53.11; P=0.028). Overall (prior to stratification by CPMR) 73 (42.4%) patients had a favorable outcome at 3 months, with no difference amongst groups.
Conclusions In patients currently deemed ineligible for MT due to large infarct ischemic cores at baseline, CPMR identifies a subgroup strongly benefiting from MT. Prospective studies are warranted.

Background: and Purpose Despite the widespread adoption of mechanical thrombectomy (MT) for the treatment of large vessel occlusion stroke (LVOS) in the anterior circulation, the optimal strategy for the treatment tandem occlusion related to cervical internal carotid artery (ICA) dissection is still debated. This individual patient pooled analysis investigated the safety and efficacy of prior intravenous thrombolysis (IVT) in anterior circulation tandem occlusion related to cervical ICA dissection treated with MT. Methods: We performed a retrospective analysis of two merged prospective multicenter international real-world observational registries: Endovascular Treatment in Ischemic Stroke (ETIS) and Thrombectomy In TANdem occlusions (TITAN) registries. Data from MT performed in the treatment of tandem LVOS related to cervical ICA dissection between January 2012 and December 2019 at 24 comprehensive stroke centers were analyzed. The primary endpoint was a favorable outcome defined as 90-day modified Rankin Scale (mRS) score of 0–2. Results: The study included 144 patients with tandem occlusion LVOS due to cervical ICA dissection, of whom 94 (65.3%) received IVT before MT. Prior IVT was significantly associated with a better clinical outcome considering the mRS shift analysis (common odds ratio, 2.59; 95% confidence interval [CI], 1.35 to 4.93; P=0.004 for a 1-point improvement) and excellent outcome (90-day mRS 0–1) (adjusted odds ratio [aOR], 4.23; 95% CI, 1.60 to 11.18). IVT was also associated with a higher rate of intracranial successful reperfusion (83.0% vs. 64.0%; aOR, 2.70; 95% CI, 1.21 to 6.03) and a lower rate of symptomatic intracranial hemorrhage (4.3% vs. 14.8%; aOR, 0.21; 95% CI, 0.05 to 0.80). Conclusions Prior IVT before MT for the treatment of tandem occlusion related to cervical ICA dissection was safe and associated with an improved 90-day functional outcome.

Background: and Purpose Despite the widespread adoption of mechanical thrombectomy (MT) for the treatment of large vessel occlusion stroke (LVOS) in the anterior circulation, the optimal strategy for the treatment tandem occlusion related to cervical internal carotid artery (ICA) dissection is still debated. This individual patient pooled analysis investigated the safety and efficacy of prior intravenous thrombolysis (IVT) in anterior circulation tandem occlusion related to cervical ICA dissection treated with MT. Methods: We performed a retrospective analysis of two merged prospective multicenter international real-world observational registries: Endovascular Treatment in Ischemic Stroke (ETIS) and Thrombectomy In TANdem occlusions (TITAN) registries. Data from MT performed in the treatment of tandem LVOS related to cervical ICA dissection between January 2012 and December 2019 at 24 comprehensive stroke centers were analyzed. The primary endpoint was a favorable outcome defined as 90-day modified Rankin Scale (mRS) score of 0–2. Results: The study included 144 patients with tandem occlusion LVOS due to cervical ICA dissection, of whom 94 (65.3%) received IVT before MT. Prior IVT was significantly associated with a better clinical outcome considering the mRS shift analysis (common odds ratio, 2.59; 95% confidence interval [CI], 1.35 to 4.93; P=0.004 for a 1-point improvement) and excellent outcome (90-day mRS 0–1) (adjusted odds ratio [aOR], 4.23; 95% CI, 1.60 to 11.18). IVT was also associated with a higher rate of intracranial successful reperfusion (83.0% vs. 64.0%; aOR, 2.70; 95% CI, 1.21 to 6.03) and a lower rate of symptomatic intracranial hemorrhage (4.3% vs. 14.8%; aOR, 0.21; 95% CI, 0.05 to 0.80). Conclusions Prior IVT before MT for the treatment of tandem occlusion related to cervical ICA dissection was safe and associated with an improved 90-day functional outcome.