Clinical effect of successful reperfusion in patients presenting with NIHSS < 8: data from the BEYOND-SWIFT registry

Multicenter evaluation of mechanical thrombectomy for distal medium vessel occlusions with National Institute of Health Stroke Scale Scores ≥ 6 and ≤ 6

BACKGROUND

While mechanical thrombectomy is considered standard of care for large vessel occlusions, scientific evidence to support treatment for distal and medium vessel occlusions remains scarce.

PURPOSE

To evaluate feasibility, safety, and outcomes in patients with low National Institute of Health Stroke Scale scores undergoing mechanical thrombectomy for treatment of distal medium vessel occlusions.

MATERIALS AND METHODS

Retrospective data review and analysis of prospectively maintained databases at 41 academic centers in North America, Asia, and Europe between January 2017 and January 2022. Characteristics and outcomes were compared between groups with low stroke scale score (≤ 6) versus and higher stroke scale scores (> 6). Propensity score matching using the optimal pair matching method and 1:1 ratio was performed.

RESULTS

Data were collected on a total of 1068 patients. After propensity score matching, there were a total of 676 patients included in the final analysis, with 338 patients in each group. High successful reperfusion rates were seen in both groups, 90.2% in ≤ 6 and 88.7% in the > 6 stroke scale groups. The frequency of excellent and good functional outcome was seen more common in low versus higher stroke scale score patients (64.5% and 81.1% versus 39.3% and 58.6%, respectively). The 90-day mortality rate observed in the ≤ 6 stroke scale group was 5.3% versus 13.3% in the > 6 stroke scale group.

CONCLUSION

Mechanical thrombectomy in distal and medium vessel occlusions, specifically in patients with low stroke scale scores is feasible, though it may not necessarily improve outcomes over IVT.

MASTRO I: Meta-Analysis and Systematic Review of thrombectomy stent retriever outcomes: comparing functional, safety and recanalization outcomes between EmboTrap, Solitaire and Trevo in acute ischemic stroke

Aim: Stent-retriever (SR) thrombectomy has demonstrated superior outcomes in patients with acute ischemic stroke compared with medical management alone, but differences among SRs remain unexplored. We conducted a Systematic Review/Meta-Analysis to compare outcomes between three SRs: EmboTrap®, Solitaire™, and Trevo®. Methods: We conducted a PRISMA-compliant Systematic Review among English-language studies published after 2014 in PubMed/MEDLINE that reported SRs in ≥25 patients. Functional and safety outcomes included 90-day modified Rankin scale (mRS 0-2), mortality, symptomatic intracranial hemorrhage (sICH), and embolization to new territory (ENT). Recanalization outcomes included modified thrombolysis in cerebral infarction (mTICI) and first-pass recanalization (FPR). We used a random effects Meta-Analysis to compare outcomes; subgroup and outlier-influencer analysis were performed to explore heterogeneity. Results: Fifty-one articles comprising 9,804 patients were included. EmboTrap had statistically significantly higher rates of mRS 0-2 (57.4%) compared with Trevo (50.0%, p = 0.013) and Solitaire (45.3%, p < 0.001). Compared with Solitaire (20.4%), EmboTrap (11.2%, p < 0.001) and Trevo (14.5%, p = 0.018) had statistically significantly lower mortality. Compared with Solitaire (7.7%), EmboTrap (3.9%, p = 0.028) and Trevo (4.6%, p = 0.049) had statistically significantly lower rates of sICH. There were no significant differences in ENT rates across all three devices (6.0% for EmboTrap, 5.3% for Trevo, and 7.7% for Solitaire, p = 0.518). EmboTrap had numerically higher rates of recanalization; however, no statistically significant differences were found. Conclusion: The results of our Systematic Review/Meta-Analysis suggest that EmboTrap may be associated with significantly improved functional outcomes compared with Solitaire and Trevo. EmboTrap and Trevo may be associated with significantly lower rates of sICH and mortality compared with Solitaire. No significant differences in recanalization and ENT rates were found. These conclusions are tempered by limitations of the analysis including variations in thrombectomy techniques in the field, highlighting the need for multi-arm RCT studies comparing different SR devices to confirm our findings.

Bridging intravenous thrombolysis in patients with atrial fibrillation

Background and purpose

40% of acute ischemic stroke patients treated by mechanical thrombectomy (MT) have a clinical history of atrial fibrillation (AF). The safety of bridging intravenous thrombolysis (IVT) (MT + IVT) is currently being discussed. We aimed to analyze the interaction between oral anticoagulation (OAC) status or AF with bridging IVT, regarding the occurrence of symptomatic intracranial hemorrhage (sICH) and functional outcome.

Materials and Methods

Multicentric observational cohort study (BEYOND-SWIFT registry) of consecutive patients undergoing MT between 2010 and 2018 (n = 2,941). Multinomial regression models were adjusted for prespecified baseline and plausible pathophysiological covariates identified on a univariate analysis to assess the association of AF and OAC status with sICH and good outcomes (90-day modified Rankin Scale score 0–2).

Results

In the total cohort (median age 74, 50.6% women), 1,347 (45.8%) patients had AF. Higher admission National Institutes of Health Stroke Scale (NIHSS) score (aOR 1.04 [95% 1.02–1.06], per point of increase) and prior medication with Vitamin K antagonists (VKA) (aOR 2.19 [95% 1.27–3.66]) were associated with sICH. Neither AF itself (aOR 0.71 [95% 0.41–1.24]) nor bridging IVT (aOR 1.08 [0.67–1.75]) were significantly associated with increased sICH. Receiving bridging IVT (aOR 1.61 [95% 1.24–2.11]) was associated with good 90-day outcome, with no interaction between AF and IVT (p = 0.92).

Conclusion

Bridging IVT appears to be a reasonable clinical option in selected patients with AF. Given the increased sICH risk in patients with VKA, subgroup analysis of the randomized controlled trials should analyze whether patients with VKA might benefit from withholding bridging IVT.

Registration

clinicaltrials.gov; Unique identifier: NCT03496064.

Mechanical Thrombectomy in Patients Presenting with NIHSS Score <6: A Safety and Efficacy Analysis

BACKGROUND AND OBJECTIVES

Groundbreaking trials have shown the tremendous efficacy of mechanical thrombectomy for large vessel occlusions. Currently, mechanical thrombectomy is limited to patients with NIHSS scores ≥6. We investigated the feasibility and safety of MT in patients presenting with NIHSS scores <6.

MATERIALS AND METHODS

A retrospective review of patient who presented with acute ischemic stroke due to large vessel occlusion with an NIHSS score <6 between 2015 - 2021. The patients were then divided into two groups: those who received mechanical thrombectomy and those who did not.

RESULTS

Among 83 patients, 41 received a mechanical thrombectomy while 42 received medical treatment only. The mean age in the mechanical thrombectomy group was 66 years versus 60 years in the medical group (p = 0.06). Risk factors for stroke did not differ significantly between both groups. 14 patients (34.1%) in the mechanical thrombectomy group and 20 (47.6%) in the medical group received tissue plasminogen activator. No significant difference in clinical improvement (NIHSS) at discharge (p=0.85) or the mRS score at 90 days (p = 0.15) was noted. Mechanical thrombectomy was associated with smaller infarct size (p=0.04) and decreased mortality (p=0.03).

CONCLUSIONS

Mechanical thrombectomy is safe and effective for patients who present with large vessel occlusions and low initial NIHSS scores. Therefore, the decision to offer the patient mechanical thrombectomy or not should not be decided by NIHSS score alone. Rather, the decision should be multifactorial with the aim of maximizing the patients' outcomes.

Mechanical Thrombectomy for Acute Stroke Due to Large-Vessel Occlusion Presenting With Mild Symptoms

Purpose: To evaluate the safety and efficacy of mechanical thrombectomy (MT) for acute stroke due to large vessel occlusion (LVO), presenting with mild symptoms.

Methods: A prospective cohort study of patients with mild ischemic stroke and LVO was conducted. Patients were divided into two groups: MT group or best medical management (MM) group. Propensity score matching (PSM) was conducted to reduce the confounding bias between the groups. The primary outcome was functional independence at 90 days. The safety outcome was symptomatic intracranial hemorrhage (sICH). Univariate and multivariate logistic regression analyses were used to identify the independent factors associated with outcomes.

Results: Among the 105 included patients, 43 were in the MT group and 62 in the MM group. Forty-three pairs of patients were generated after PSM. There were no significant differences in sICH rates between two groups (p = 1.000). The MT group had a higher proportion of independent outcomes (83.7% MT vs. 67.4% MM; OR 2.483; 95% CI 0.886–6.959; p = 0.079) and excellent outcomes (76.7% MT vs. 51.2% MM; OR 3.150; 95% CI 1.247–7.954; p = 0.013) compared to the MM group, especially in patients with stroke of the anterior circulation (p < 0.05). Multivariate logistic regression analysis showed that small infarct core volume (p = 0.015) and MT treatment (p = 0.013) were independently associated with excellent outcomes.

Conclusions: Our results suggest that MT in stroke patients, presenting with mild symptoms, due to acute LVO in the anterior circulation may be associated with satisfactory clinical outcomes.

Clinical Trial Registration:ClinicalTrials.gov, identifier: NCT04526756.

Indian College of Radiology and Imaging (ICRI) Consensus Guidelines for the Early Management of Patients with Acute Ischemic Stroke: Imaging and Intervention

The medical science has witnessed significant change in the management of acute stroke patients as a result of recent advances in the field of stroke imaging and endovascular mechanical thrombectomy in addition to intravenous thrombolysis and optimization of stroke services in balance with available resources. Despite initial negative trials, we witnessed the publication of five multicenter randomized clinical trials showing superiority of the endovascular approach over standard medical management in patients with large vessel occlusion. The aim of this study is to provide comprehensive set of evidence-based recommendations regarding imaging and endovascular interventions in acute ischemic stroke patients.

Impact of recanalisation by mechanical thrombectomy in mild acute ischemic stroke with large anterior vessel occlusion

BACKGROUND

The net clinical benefit of mechanical thrombectomy (MT) in patients presenting acute anterior circulation ischemic stroke with large-vessel occlusion (AIS-LVO) and mild neurological deficit is uncertain.

AIMS

To investigate efficacy and safety of MT in patients with acute AIS-LVO and mild neurological deficit by evaluating i) the influence of recanalisation on three-month outcome and ii) mortality, symptomatic intracerebral hemorrhage (sICH) and procedural complications.

METHODS

We included consecutive patients with acute AIS-LVO and National Institute of Stroke Scale (NIHSS) score<8, treated by MT at Lille University Hospital. Recanalisation was graded according to modified thrombolysis in cerebral infarction (mTICI) score, mTICI 2b/2c/3 being considered successful. We recorded procedural complications and classified intra-cerebral hemorrhages (ICH) and sICH according with European Cooperative Acute Stroke Study (ECASS) and ECASS2 criteria. Three-month outcome was evaluated by modified Rankin scale (mRS). Excellent and favourable outcomes were respectively defined as mRS 0-1 and 0-2 (or similar to pre-stroke).

RESULTS

We included 95 patients. At three months, 56 patients (59. 0%) achieved an excellent outcome and 69 (72, 6%) a favourable outcome, both being more frequent in patients with successful recanalisation than in patients without (excellent outcome 71, 1% versus 10, 5%, P<0.001 and favourable outcome 82.9% versus 31.6%, P<0.001). The difference remained unchanged after adjustment for age and pre-MT infarct volume. Similar results were observed in patients with pre-MT NIHSS ≤5. Death occurred in five patients (5.3%), procedural complications in 12 (12.6%), any ICH in 38 (40.0%), including 3 (3.2%) sICH.

CONCLUSIONS

Achieving successful recanalisation appears beneficial and safe in acute AIS-LVO patients with NIHSS<8 before MT.

More expansive horizons: a review of endovascular therapy for patients with low NIHSS scores

While the landmark 2015 stroke trials demonstrated that endovascular therapy (EVT) was superior to medical management for the treatment of acute ischemic stroke due to large vessel occlusion, the efficacy of EVT for patients presenting with a low NIHSS score remains undetermined. We conducted a review of the EVT low National Institutes of Health Stroke Scale (NIHSS) stroke literature, identifying 24 quantitative and six qualitative publications. Details of study designs and outcome were extracted and critically discussed.All identified qualitative studies were retrospective. There was significant study design heterogeneity, with 18 unique study designs between the 24 identified quantitative manuscripts. Study investigations included low NIHSS EVT feasibility (n=6), EVT versus best medical management (BMM; n=10), EVT versus intravenous therapy (IVT, n=3), and low NIHSS score versus high NIHSS score (n=3). From single-arm EVT feasibility studies, the reported ranges of modified Thrombolysis in Cerebral Infarction and symptomatic intracranial hemorrhage were 78-97% and 0-10%, respectively. The EVT versus BMM literature had heterogeneous results with 40% reporting benefit with EVT and 60% reporting neutral findings. None of the studies comparing EVT with IVT reported a difference between the two revascularization therapies. The four identified meta-analyses had incongruent inclusion criteria and conflicting results. Two randomized trials are currently investigating EVT in patients with a low NIHSS score. Selected meta-analyses do suggest a potential benefit of EVT over BMM; however, current and future randomized clinical trials will better elucidate the efficacy of EVT in this patient population.

Effect of Pre- and In-Hospital Delay on Reperfusion in Acute Ischemic Stroke Mechanical Thrombectomy

Supplemental Digital Content is available in the text.

Background and Purpose:

Post hoc analyses of randomized controlled clinical trials evaluating mechanical thrombectomy have suggested that admission-to-groin-puncture (ATG) delays are associated with reduced reperfusion rates. Purpose of this analysis was to validate this association in a real-world cohort and to find associated factors and confounders for prolonged ATG intervals.

Methods:

Patients included into the BEYOND-SWIFT cohort (Bernese-European Registry for Ischemic Stroke Patients Treated Outside Current Guidelines With Neurothrombectomy Devices Using the Solitaire FR With the Intention for Thrombectomy; https://www.clinicaltrials.gov; Unique identifier: NCT03496064) were analyzed (n=2386). Association between baseline characteristics and ATG was evaluated using mixed linear regression analysis. The effect of increasing symptom-onset-to-admission and ATG intervals on successful reperfusion (defined as Thrombolysis in Cerebral Infarction [TICI] 2b-3) was evaluated using logistic regression analysis adjusting for potential confounders.

Results:

Median ATG was 73 minutes. Prolonged ATG intervals were associated with the use of magnetic resonance imaging (+19.1 [95% CI, +9.1 to +29.1] minutes), general anesthesia (+12.1 [95% CI, +3.7 to +20.4] minutes), and borderline indication criteria, such as lower National Institutes of Health Stroke Scale, late presentations, or not meeting top-tier early time window eligibility criteria (+13.8 [95% CI, +6.1 to +21.6] minutes). There was a 13% relative odds reduction for TICI 2b-3 (adjusted odds ratio [aOR], 0.87 [95% CI, 0.79–0.96]) and TICI 2c/3 (aOR, 0.87 [95% CI, 0.79–0.95]) per hour ATG delay, while the reduction of TICI 2b-3 per hour increase symptom-onset-to-admission was minor (aOR, 0.97 [95% CI, 0.94–0.99]) and inconsistent regarding TICI 2c/3 (aOR, 0.99 [95% CI, 0.97–1.02]). After adjusting for identified factors associated with prolonged ATG intervals, the association of ATG delay and lower rates of TICI 2b-3 remained tangible (aOR, 0.87 [95% CI, 0.76–0.99]).

Conclusions:

There is a great potential to reduce ATG, and potential targets for improvement can be deduced from observational data. The association between in-hospital delay and reduced reperfusion rates is evident in real-world clinical data, underscoring the need to optimize in-hospital workflows. Given the only minor association between symptom-onset-to-admission intervals and reperfusion rates, the causal relationship of this association warrants further research.

Registration:

URL: https://www.clinicaltrials.gov. Unique identifier: NCT03496064.

Role of Non-Perfusion Factors in Mildly Symptomatic Large Vessel Occlusion Stroke

INTRODUCTION

Uncertainty regarding reperfusion of mildly-symptomatic (minor) large vessel occlusion (LVO)-strokes exists. Recently, benefits from reperfusion were suggested. However, there is still no strong data to support this. Furthermore, a proportion of those patients don't improve even after non-hemorrhagic reperfusion. Our study evaluated whether or not non-perfusion factors account for such persistent deconditioning.

METHODS

Patients with identified minor LVO-strokes (NIHSS ≤ 8) from our stroke alert registry between January-2016 and May-2018 were included. Variables/ predictors of outcome were tested using univariate/multivariate logistic and linear regression analyses. Three month-modified ranking scale (mRS) was used to differentiate between favorable (mRS = 0-2) and unfavorable outcomes (mRS = 3-6).

RESULTS

Eighty-one patients were included. Significant differences between the two outcome groups regarding admission-NIHSS and discharge-NIHSS existed (OR = 0.47, 0.49 / p = 0.0005, <0.0001 respectively).The two groups had matching perfusion measures. In the poor outcome group, discharge-NIHSS was unchanged from the admission-NIHSS while in the good outcome group, discharge-NIHSS significantly improved.

CONCLUSION

Admission and discharge NIHSS are independent predictors of outcome in patients with minor-LVO strokes. Unchanged discharge-NIHSS predicts worse outcomes while improved discharge-NIHSS predicts good outcomes. Unchanged NIHSS in the poor outcome group was independent of the perfusion parameters. In literature, complement activation and pro-inflammatory responses to ischemia might account for the progression of stroke symptoms in major-strokes. Our study concludes similar phenomena might be present in minor-strokes. Therefore, discharge-NIHSS may be useful as a clinical marker for future therapies.

Association of initial imaging modality and futile recanalization after thrombectomy

Objective

To test the hypothesis that selection by initial imaging modality (MRI vs CT) is associated with rate of futile recanalizations (FRs) after mechanical thrombectomy (MT), we assessed this association in a multicenter, retrospective observational registry (BEYOND-SWIFT [Registry for Evaluating Outcome of Acute Ischemic Stroke Patients Treated With Mechanical Thrombectomy], NCT03496064).

Methods

In 2,011 patients (49.7% female, median age 73 years [61–81]) included between 2009 and 2017, we performed univariate and multivariate analyses regarding the occurrence of FR. FRs were defined as 90-day modified Rankin Scale (mRS) score 4–6 despite successful recanalization in patients selected by MRI (n = 690) and CT (n = 1,321) with a sensitivity analysis considering only patients with mRS 5–6 as futile.

Results

MRI as compared to CT resulted in similar rates of subsequent MT (adjusted odds ratio [aOR] 1.048, 95% confidence interval [CI] 0.677–1.624). Rates of FR were as follows: 571/1,489 (38%) FR mRS 4–6 including 393/1,489 (26%) FR mRS 5–6. CT-based selection was associated with increased rates of FRs compared to MRI (44% [41%–47%] vs 29% [25%–32%], p < 0.001; aOR 1.77 [95% CI 1.25–2.51]). These findings were robust in sensitivity analysis. MRI-selected patients had a delay of approximately 30 minutes in workflow metrics in real-world university comprehensive stroke centers. However, functional outcome and mortality were more favorable in patients selected by MRI compared to patients selected with CT.

Conclusions

CT selection for MT was associated with an increased risk of FRs as compared to MRI selection. Efforts are needed to shorten workflow delays in MRI patients. Further research is needed to clarify the role of the initial imaging modality on FR occurrence and to develop a reliable FR prediction algorithm.

Endovascular Stroke Treatment and Risk of Intracranial Hemorrhage in Anticoagulated Patients

Background and Purpose- We aimed to determine the safety and mortality after mechanical thrombectomy in patients taking vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs). Methods- In a multicenter observational cohort study, we used multiple logistic regression analysis to evaluate associations of symptomatic intracranial hemorrhage (sICH) with VKA or DOAC prescription before thrombectomy as compared with no anticoagulation. The primary outcomes were the rate of sICH and all-cause mortality at 90 days, incorporating sensitivity analysis regarding confirmed therapeutic anticoagulation. Additionally, we performed a systematic review and meta-analysis of literature on this topic. Results- Altogether, 1932 patients were included (VKA, n=222; DOAC, n=98; no anticoagulation, n=1612); median age, 74 years (interquartile range, 62-82); 49.6% women. VKA prescription was associated with increased odds for sICH and mortality (adjusted odds ratio [aOR], 2.55 [95% CI, 1.35-4.84] and 1.64 [95% CI, 1.09-2.47]) as compared with the control group, whereas no association with DOAC intake was observed (aOR, 0.98 [95% CI, 0.29-3.35] and 1.35 [95% CI, 0.72-2.53]). Sensitivity analyses considering only patients within the confirmed therapeutic anticoagulation range did not alter the findings. A study-level meta-analysis incorporating data from 7462 patients (855 VKAs, 318 DOACs, and 6289 controls) from 15 observational cohorts corroborated these observations, yielding an increased rate of sICH in VKA patients (aOR, 1.62 [95% CI, 1.22-2.17]) but not in DOAC patients (aOR, 1.03 [95% CI, 0.60-1.80]). Conclusions- Patients taking VKA have an increased risk of sICH and mortality after mechanical thrombectomy. The lower risk of sICH associated with DOAC may also be noticeable in the acute setting. Improved selection might be advisable in VKA-treated patients. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT03496064. Systematic Review and Meta-Analysis: CRD42019127464.

Real-world effects of late window neurothrombectomy: procedure rates increase without night-time bias

INTRODUCTION

With the expansion of the interventional time window for stroke from emergent large vessel occlusion (ELVO), the rate of mechanical thrombectomy (MT) is expected to rise, potentially causing higher burnout rates and requiring hospitals to develop strategies for adequate coverage of these procedures.

METHODS

Neurointerventional physicians at 10 participating stroke centers prospectively recorded time requirements for all MT consultations over 30 consecutive 24-hour call periods, including both false positive consultations and MT procedures, during mid to late 2018. Consult start time, procedure start and end time, and data regarding commute to the hospital and delay in scheduled procedures were collected and compared with those from an identical prospective study performed in 2017.

RESULTS

Data were collected from a total of 300 days of call. A total of 166 procedures were performed (mean 0.55 per day), an increase from 0.32 per day in 2017. Overall mean MT direct time burden during each 24-hour call was 124 min (compared with 85 min in 2017). The percentage of consultations for thrombectomy varied based on time of day, with 87% of consults between the hours of midnight and 04:00 proceeding to thrombectomy compared with 37% between the hours of 16:00 and 20:00.

CONCLUSIONS

MT procedural volumes have increased from one every 5 days in 2016 to one every 2 days in 2018. The highest percentage of consults leading to thrombectomy occur in the early morning hours after midnight. Compared with similar data from 2016 and 2017, call demands continue to escalate, representing a significant demand on neurointerventional teams.

Mechanical thrombectomy for basilar artery occlusion: efficacy, outcomes, and futile recanalization in comparison with the anterior circulation

BACKGROUND

Performing mechanical thrombectomy (MT) in patients with basilar artery occlusion (BAO) is currently not evidence-based.

OBJECTIVE

To compare patients' outcome, relative merits of achieving recanalization, and predictors of futile recanalization (FR) between BAO and anterior circulation large vessel occlusion (ACLVO) MT.

METHODS

In the multicenter BEYOND-SWIFT registry (NCT03496064), univariate and multivariate (displayed as adjusted Odds Ratios, aOR and 95% confidence intervals, 95%-CI) outcome comparisons between BAO (N=165) and ACLVO (N=1574) were performed. The primary outcome was favorable outcome at 90 days (modified Rankin Scale, mRS 0-2). Secondary outcome included mortality, symptomatic intracranial hemorrhage (sICH) and FR. The relative merits of achieving successful recanalization between ACLVO and BAO were evaluated with interaction terms.

RESULTS

MT in BAO was more often technically effective and equally safe in regards to mortality and sICH when compared to ACLVO. When adjusting for baseline differences, there was no significant difference between BAO vs ACLVO regarding rates of favorable outcome (aOR 0.986, 95%-CI 0.553 - 1.758). However, BAO were associated with increased rates of FR (aOR 2.146, 95%-CI 1.267 - 3.633). Predictors for FR were age, stroke severity, maneuver count and intracranial stenting. No significant heterogeneity on the relative merits of achieving successful recanalization on several outcome parameters were observed when comparing BAO and ACLVO.

CONCLUSIONS

In selected patients, similar outcomes can be achieved in BAO and ACLVO patients treated with MT. Randomized controlled trials comparing patient selection and interventional strategies seem warranted to avoid FR.

TRIAL REGISTRATION NUMBER

NCT03496064.

Outcome, efficacy and safety of endovascular thrombectomy in ischaemic stroke according to time to reperfusion: data from a multicentre registry

BACKGROUND AND PURPOSE

In acute ischaemic stroke (AIS) of the anterior circulation (AC) treated with mechanical thrombectomy (MT), data point to a decline of treatment effect with increasing time from symptom onset to treatment. However, the magnitude of the decline will depend on the clinical setting and imaging selection used. The aims of this study were (1) to evaluate the clinical effect of time to reperfusion (TTR); and (2) to assess the safety and technical efficacy of MT according to strata of TTR.

METHODS

Using the retrospective multicentre BEYOND-SWIFT registry data (ClinicalTrials.gov identifier: NCT03496064), we compared safety and efficacy of MT in 1461 patients between TTR strata of 0-180 min (n = 192), 180-360 min (n = 876) and >360 min (n = 393). Clinical effect of TTR was evaluated using multivariable logistic regression analyses adjusting for pre-specified confounders [adjusted odds ratios (aOR) and 95% confidence intervals (95% CI)]. Primary outcome was good functional outcome (modified Rankin Scale: mRS 0-2) at day 90.

RESULTS

Every hour delay in TTR was a significant factor related to mRS 0-2 (aOR 0.933, 95% CI 0.887-0.981) with an estimated 1.5% decreased probability of good functional outcome per hour delay of reperfusion, and mRS 0-1 (aOR 0.929, 95% CI 0.877-0.985). Patients with late TTR had lower rates of successful and excellent reperfusion, higher complication rates and number of passes.

CONCLUSIONS

TTR is an independent factor related to long-term functional outcome. With increasing TTR, interventional procedures become technically less effective. Efforts should be made to shorten TTR through optimized prehospital and in-hospital pathways.