Welcome to the WSC 2021 Interactive Program

Background and Aims

The RACECAT trial showed no superiority in transferring patients with high pre-hospital risk of large vessel occlusion (LVO) directly to an Endovascular Treatment Stroke Center (EVT-SC) compared to Local-SC. We explored whether patients with ischemic stroke might benefit from different transfer protocols according to the presence or absence of LVO.

Methods

From the modified intention-to-treat (m-ITT) population with final diagnosis of ischemic stroke (920/1401) we selected patients with available vascular imaging at first referring center. In LVO and no-LVO groups we analyzed the adjusted OR of EVT-SC transfer for better outcome (ordinal modified Rankin Scale) at 90-day follow-up, and compared the frequency of reperfusion therapies between both transfer protocols.

Results

Amongst the m-ITT population, 505 (55%) had LVO, 184 (20%) had no LVO, and 231 (25%) had undetermined LVO. Three hundred seven/505 LVO (61%) and 122/184 no-LVO (66%) patients were transferred directly to EVT-SC (p=0.187). The adjusted OR (95% CI) of EVT-SC transfer for better outcome was 0.86 (0.61-1.21) and 1.10 (0.62-1.93) in LVO and no-LVO groups, respectively. IV thrombolysis was administered more frequently in Local-SC (vs. EVT-SC) in both groups [LVO: 138 (70%) vs. 154 (50%), p<0.001; no-LVO: 39 (63%) vs. 56 (46%), p=0.029]. Thrombectomy was performed more frequently in LVO patients transferred directly to EVT-SC compared to Local-SC [212 (69%) vs. 109 (55%), p=0.001].

Conclusions

This exploratory analysis found no differences in functional outcome between both transfer models in the selected population of patients with final diagnosis of ischemic stroke independently of the presence or absence of LVO on vascular imaging.

Background and Aims

Intravenous thrombolysis (IVT) can reduce disability after acute ischaemic stroke. The IVT rate in the UK (as a percentage of all strokes) has remained stable at 11-12% over the past 7 years.

Methods

Data from January 2019-December 2020 were extracted from the Sentinel Stroke National Audit Programme (SSNAP), a national registry covering 92% of the UK population. For all stroke admissions, we compared the annual and monthly IVT rates at national and regional level. Chi-squared was used to test the differences between cohorts.

Results

174,321 stroke patients were admitted to acute hospitals over two years. The national IVT rate decreased from 11.6% in 2019 to 11% in 2020, p<0.001. During the first UK COVID peak in March/April 2020, the IVT rate remained stable (11.6% in 2019 compared to 11.8% in 2020, p=0.652). However, IVT rates began to fall after April 2020, with a pronounced decline from autumn onwards (10.2% in September-December 2020 compared to 11.6% in September-December 2019, p<0.001).

Conclusions

Data shows that whilst the IVT rate was maintained during the early months of the pandemic (March-April 2020), rates began to decline through mid to late 2020. Further investigation is required to determine the underlying cause(s), which may include admission rates, organisational changes and increases in pre-hospital and in-hospital pathway timings, as well as to explore regional differences, as the pandemic affected different UK regions at different intensities.

Background and Aims

Mechanical thrombectomy (MT) in acute ischaemic stroke can reduce the severity of post-stroke disability. The MT rate in the UK (as a percentage of all strokes) has been steadily increasing from 0.7% in 2016/17 to 1.8% in 2019/20.

Methods

Data from January 2019 to December 2020 were extracted from the Sentinel Stroke National Audit Programme (SSNAP), a national registry covering 92% of the UK population. For all stroke admissions, we compared the annual and monthly MT rates at a national and regional level. Chi-squared was used to test the differences between cohorts.

Results

174,321 stroke patients were admitted to acute hospitals over two years. The proportion of patients receiving MT increased from 1.69% in 2019 to 1.94% in 2020, p<0.001. No reduction in MT rates was observed during the COVID period, however the previous gradual increase has slowed.

Conclusions

Whilst the national MT rate has remained consistent with pre-COVID levels demonstrating that access to the treatment has been maintained throughout the pandemic, the rate has fallen short of the expected year-on-year growth and arrested the trajectory towards the NHS ambition of a 10% MT rate by 2022.

Background and Aims

The Austrian Prehospital Stroke Scale (APSS) score was developed to predict large vessel occlusion (LVO) and improve prehospital transportation triage. Its accuracy has been previously analyzed retrospectively. We now aimed to investigate the accuracy as well as the impact of the implementation of a triage strategy using this score on treatment times and outcome in a prospective study.

Methods

Prospective diagnostic test accuracy and before-after interventional study. EMS prospectively evaluated APSS in patients suspected of stroke. Accuracy was compared to other LVO scores. Patients with APSS ≥ 4 points were brought directly to the comprehensive stroke center. Treatment time frames, neurological and radiological outcome before and after the APSS implementation were compared.

Results

A total of 307 patients with suspected stroke were included from October 2018 to February 2020. Treatable LVO was present in 79 (26%). Sensitivity of APSS to detect those was 90%, specificity 79%, positive predictive value 66%, negative predictive value 95%, area under the curve 0.87 (95%CI 0.83-0.91). This was similar to in-hospital NIHSS (AUC 0.89 95%CI 0.89- 0.92, p=0.06), RACE (AUC 0.88 95%CI 0.87-0.908) and superior to CPSS (AUC 0.83 95%CI 0.78-0.87, p=0.01). Implementation of APSS triage increased direct transportation rate (21% before vs. 52% after; p<0.001) with a significant time benefit (alert to groin puncture time benefit: 51 minutes (95%CI 28-74; p<0.001). Neurological and radiological outcome did not differ significantly.

Conclusions

APSS triage showed an accuracy comparable to in-hospital NIHSS, and lead to a significant optimization of prehospital workflows in patients with potential LVO.

Background and Aims

BACKGROUND AND PURPOSE: Mechanical Thrombectomy (MT) is

standard of care for patients presenting with acute ischemic stroke due to large vessel

occlusion. We report main clinical outcomes of patients receiving MT

Methods

METHODS: Retrospective analysis of prospectively collected stroke database of patients receiving MT at our comprehensive stroke centre (CSC) – ”direct-to-mothership” model versus transferred from twenty-one primary stroke centres (PSC) – ”drip-and-ship” model; serving 46,153 km² in Queensland, Australia between January 2015 and December 2018

Results

RESULTS: Out of 187, 103 (55%) presented directly to the CSC versus 84 (45%) transferred from PSCs. The transfer group demonstrated a longer median time from symptom-onset to groin puncture (354, IQR: 229-452 mins, p<0.001) compared to the direct group (216, IQR: 145-275 mins). 90-day functional independence defined as modified Rankin Scale 0-2 (61.1% vs 61.9%), 90-day mortality (22.3% vs 20.2%), successful recanalization defined as Thrombolysis in Cerebral Infarction Score 2b-3 (88.3% vs 86.9%) or any hemorrhagic transformation (22.5% vs 25.0%) were similar in both groups (p>0.05). Subgroup analysis of transferred patients demonstrated reduced odds of achieving 90-day functional independence (OR: 0.989, CI: 0.980-0.998, p<0.02) and increased odds of 90-day mortality (OR:1.009, CI:1.002-1.015, p<0.02) with increasing distance and door-to-door times respectively, between the PSC and CSC.

Conclusions

CONCLUSION: Our twenty-two-centre network experience confirms real world reproducibility of trial results and similar functional outcomes in both models.

Background and Aims

Previous studies showed conflicting results in the benefits of pretreatment with IVT before endovascular treatment (EVT) for acute ischemic stroke (AIS) patients with large vessel occlusions (LVOs). The aim of this study was to investigate the clinical efficacy and safety of EVT alone versus bridging therapy (BT) in AIS with LVOs.

Methods

A systematic review and meta-analysis of all available studies evaluating clinical outcomes between BT and EVT alone were conducted by electronic searching the NCBI/NLM PubMed and Web of Science database from inception to October 20, 2020. Primary outcomes focus on 90 days good outcome and mortality. Secondary outcomes included successful reperfusion, and sICH. The random-effect model was applied if P＜0.10 for Cochran’s Q test or I²＞50% for Higgins I² statistics, otherwise the fixed-effect model was performed.

Results

A total of 93 studies enrolling 45,190 patients were admitted in present analysis. In both unadjusted and adjusted analysis, BT was associated with a higher likelihood of 90 days good outcome (crude odds ratio [cOR] 1.361, 95%CI 1.234-1.502 and adjusted OR[aOR] 1.369, 95%CI 1.217-1.540), successful reperfusion (cOR 1.271, 95%CI 1.149-1.406 and aOR 1.267, 95%CI 1.095-1.465) and lower odds of 90 days mortality (cOR 0.619, 95%CI 0.560-0.684 and aOR 0.718, 95%CI 0.594-0.868) compared with EVT alone. The two groups did not differ in sICH (cOR 1.062, 95%CI 0.915-1.232 and aOR 1.20, 95%CI 0.95-1.47) after evaluating by sensitivity analyses and adjusting for publication bias.

Conclusions

BT benefited more in clinical outcome without increasing the risk of safety compared with EVT alone in AIS patients with LVOs.