Benefit of successful reperfusion achieved by endovascular thrombectomy for patients with ischemic stroke and moderate pre-stroke disability (mRS 3): results from the MR CLEAN Registry

Pre-stroke Functional Status in Patients Undergoing Mechanical Thrombectomy: How Relevant Are False Estimations in the Emergency Setting?

PURPOSE

The modified Rankin scale (mRS) is frequently used in the emergency setting to estimate pre-stroke functional status in stroke patients who are candidates to acute revascularization therapies (ps-mRS). We aimed to describe the agreement between pre-stroke mRS evaluated in the emergency department (ED-ps-mRS) and pre-stroke mRS evaluated comprehensively post-admission (PA-ps-mRS).

METHODS

Retrospective study of consecutive ischemic stroke patients undergoing mechanical thrombectomy, with available ED-ps-mRS and PA-ps-mRS. ED-ps-mRS was evaluated by the treating neurologist and documented in the emergency stroke treatment protocol. PA-ps-mRS was retrospectively evaluated with information registered in the clinical record. Collection of baseline characteristics and 3‑month outcomes. Patients with ED-overestimated pre-stroke functional status (ED ps-mRS ≤ 2 and PA-ps-mRS ≥ 3) were compared to correct low and high ED-ps-mRS groups.

RESULTS

We included 409 patients (median age 77 years, 50% female, median NIHSS 14). Concordance of dichotomized ED-ps-mRS and PA-ps-mRS (0-2 vs. 3-5) was found in 81.4% (Cohen's kappa = 0.476, p < 0.001). ED-overestimated pre-stroke functional status was found in 69 patients (17%). Patients with ED-overestimated pre-stroke functional status were older (p < 0.001), more frequently presented diabetes (p < 0.001), previous stroke (p = 0.014) and less frequently presented 3‑month functional independence (p < 0.001) compared to patients with correct low ED-ps-mRS. No differences in pre-stroke baseline characteristics between overestimated and correct high ED-ps-mRS was found.

CONCLUSION

Disagreement between dichotomized ED-ps-mRS and PA-ps-mRS (0-2 vs. 3-5) occurred in 1/5 of patients. Overestimation of pre-stroke functional status may falsely reduce the expected proportion of patients achieving favourable 3‑month functional outcomes.

Outcomes and safety of endovascular treatment from 6 to 24 hours in patients with a pre-stroke moderate disability (mRS 3): a multicenter retrospective study

BACKGROUND

Approximately 30% of patients presenting with acute ischemic stroke (AIS) due to large vessel occlusion have pre-stroke modified Rankin Scale (mRS) scores ≥2. We aimed to investigate the safety and outcomes of endovascular treatment (EVT) in patients with AIS with moderate pre-stroke disability (mRS score 3) in an extended time frame (ie, 6-24 hours from the last time known well).

METHODS

Data were collected from five centers in Europe and the USA from January 2018 to January 2023 and included 180 patients who underwent EVT in an extended time frame. Patients were divided into two groups of 90 each (Group 1: pre-mRS 0-2; Group 2: pre-mRS 3; 71% women, mean age 80.3±11.9 years). Primary outcomes were: (1) 3-month good clinical outcome (Group 1: mRS 0-2, Group 2: mRS 0-3) and ΔmRS; (2) any hemorrhagic transformation (HT); and (3) symptomatic HT. Secondary outcomes were successful and complete recanalization after EVT and 3-month mortality.

RESULTS

No between-group differences were found in the 3-month good clinical outcome (26.6% vs 25.5%, P=0.974), any HT (26.6% vs 22%, P=0.733), and symptomatic HT (8.9 vs 4.4%, P=0.232). Unexpectedly, ΔmRS was significantly smaller in Group 2 compared with Group 1 (1.64±1.61 vs 2.97±1.69, P<0.001). No between-group differences were found in secondary outcomes.

CONCLUSION

Patients with pre-stroke mRS 3 are likely to have similar outcomes after EVT in the extended time frame to those with pre-stroke mRS 0-2, with no difference in safety.

Utilization, Workflow, and Outcomes of Endovascular Thrombectomy in Patients With vs Without Premorbid Disability in a National Registry

Background and Objectives

Given the paucity of high-quality safety/efficacy data on acute stroke therapies in patients with premorbid disability, they risk being routinely excluded from such therapies. We examined utilization of endovascular thrombectomy (EVT), associated workflow, and poststroke outcomes among patients with vs without premorbid disability.

Methods

We used national registry data on thrombolysis/EVT for the Czech Republic from 1 January 2016 to 31 December 2020. Premorbid disability was defined as prestroke modified Rankin Scale score (mRS) ≥3. We compared proportions of patients with vs without premorbid disability who received EVT and examined workflow times. We compared ΔmRS-change in mRS from prestroke to 3 months-in patients with vs without premorbid disability, in addition to intracerebral hemorrhage (ICH), mortality, and discharge NIHSS (National Institutes of Health Stroke Scale score), adjusting for age, sex, baseline NIHSS, and comorbidities, and verified using propensity score weighting (PSW) and matching for differences in treatment assignment. We stratified by age group (<65, 65-74, 75-84, ≥85 years) to explore outcome heterogeneity with vs without premorbid disability.

Results

Among 22,405 patients with ischemic stroke who received thrombolysis/EVT/both, 1,712 (7.6%) had prestroke mRS ≥ 3. Patients with prestroke disability were less likely to receive EVT vs those without (10.1% vs 20.7%, aOR: 0.30, 95% CI 0.24-0.36). When treated, they had longer door-to-arterial puncture times (median: 75 minutes, IQR: 58-100 vs 54, IQR: 27-77, adjusted difference: 12.5, 95% CI 2.68-22.3). Patients with prestroke disability receiving thrombolysis/EVT/both had worse ΔmRS (adjusted rate ratio, aIRR on PSW: 1.57, 95% CI 1.43-1.72), rates of 3-month mRS 5-6, discharge NIHSS, and mortality (aOR-PSW [mortality]: 2.54, 95% CI 1.92-3.34), while ICH did not significantly differ. 32.1% of patients with prestroke disability receiving thrombolysis/EVT/both successfully returned to prestroke state, but this proportion ranged from 19.6% for those older than 85 years to 66.0% for those younger than 65 years. Regardless of premorbid disability, EVT was associated with better outcomes including lower ΔmRS (aIRR-PSW: 0.87, 95% CI 0.83-0.91) and mortality, with no interaction of treatment effect by premorbid disability status (e.g., mortality pinteraction = 0.73). EVT recipients with premorbid disability did not differ significantly for several outcomes including ΔmRS (aIRR: 0.99, 95% CI 0.84-1.17) but were more likely to have 3-month mRS 5-6 (70.1% vs 39.5% without premorbid disability, aOR: 1.85, 95% CI 1.12-3.04).

Discussion

Patients with premorbid disability were less likely to receive EVT, had slower treatment times, and had worse outcomes compared with patients without premorbid disability. However, regardless of premorbid disability, patients fared better with EVT vs medical management and one-third with prestroke disability returned to their prestroke status.

Trial selection criteria should not be used for clinical decisions and recommendations: the thrombectomy trials example

BACKGROUND

Despite multiple calls for more inclusive studies, most clinical trial eligibility criteria remain too restrictive. Thrombectomy trials have been no exception.

METHODS

We review the landmark trials that have shown the benefits of thrombectomy, their eligibility criteria, and consequences on clinical practice. We discuss the rationale behind various reasons for exclusions. We also examine the logical problem involved in using eligibility criteria as indications for treatment.

RESULTS

Most thrombectomy trials have been too restrictive. This has been shown by a plethora of follow-up studies that have refuted most of the previously recommended trial eligibility restrictions. Meanwhile, the effect of clinical recommendations based on restrictive eligibility criteria is that treatment has been denied to the majority of patients who could have benefitted. Trial eligibility criteria cannot be used to make clinical decisions or recommendations unless, like any other medical diagnosis, they have been shown capable of reliably differentiating patients into those that will, and those that will not benefit from treatment. This goal can only be achieved with all-inclusive pragmatic trials.

CONCLUSION

Restrictive eligibility criteria render clinical trials incapable of guiding medical decisions or recommendations.

Predictors of In-Hospital Mortality after Thrombectomy in Anterior Circulation Large Vessel Occlusion: A Retrospective, Machine Learning Study

BACKGROUND

Despite the increased use of mechanical thrombectomy (MT) in recent years, there remains a lack of research on in-hospital mortality rates following the procedure, the primary factors influencing these rates, and the potential for predicting them. This study aimed to utilize interpretable machine learning (ML) to help clarify these uncertainties.

METHODS

This retrospective study involved patients with anterior circulation large vessel occlusion (LVO)-related ischemic stroke who underwent MT. The patient division was made into two groups: (I) the in-hospital death group, referred to as miserable outcome, and (II) the in-hospital survival group, or favorable outcome. Python 3.10.9 was utilized to develop the machine learning models, which consisted of two types based on input features: (I) the Pre-MT model, incorporating baseline features, and (II) the Post-MT model, which included both baseline and MT-related features. After a feature selection process, the models were trained, internally evaluated, and tested, after which interpretation frameworks were employed to clarify the decision-making processes.

RESULTS

This study included 602 patients with a median age of 76 years (interquartile range (IQR) 65-83), out of which 54% (n = 328) were female, and 22% (n = 133) had miserable outcomes. Selected baseline features were age, baseline National Institutes of Health Stroke Scale (NIHSS) value, neutrophil-to-lymphocyte ratio (NLR), international normalized ratio (INR), the type of the affected vessel ('Vessel type'), peripheral arterial disease (PAD), baseline glycemia, and premorbid modified Rankin scale (pre-mRS). The highest odds ratio of 4.504 was observed with the presence of peripheral arterial disease (95% confidence interval (CI), 2.120-9.569). The Pre-MT model achieved an area under the curve (AUC) value of around 79% utilizing these features, and the interpretable framework discovered the baseline NIHSS value as the most influential factor. In the second data set, selected features were the same, excluding pre-mRS and including puncture-to-procedure-end time (PET) and onset-to-puncture time (OPT). The AUC value of the Post-MT model was around 84% with age being the highest-ranked feature.

CONCLUSIONS

This study demonstrates the moderate to strong effectiveness of interpretable machine learning models in predicting in-hospital mortality following mechanical thrombectomy for ischemic stroke, with AUCs of 0.792 for the Pre-MT model and 0.837 for the Post-MT model. Key predictors included patient age, baseline NIHSS, NLR, INR, occluded vessel type, PAD, baseline glycemia, pre-mRS, PET, and OPT. These findings provide valuable insights into risk factors and could improve post-procedural patient management.

Outcomes of patients with pre-existing disability managed by mobile stroke units: A sub-analysis of the BEST-MSU study

BACKGROUND

Few data exist on acute stroke treatment in patients with pre-existing disability (PD) since they are usually excluded from clinical trials. A recent trial of mobile stroke units (MSUs) demonstrated faster treatment and improved outcomes, and included PD patients.

AIM

To determine outcomes with tissue plasminogen activator (tPA), and benefit of MSU versus management by emergency medical services (EMS), for PD patients.

METHODS

Primary outcomes were utility-weighted modified Rankin Scale (uw-mRS). Linear and logistic regression models compared outcomes in patients with versus without PD, and PD patients treated by MSU versus standard management by EMS. Time metrics, safety, quality of life, and health-care utilization were compared.

RESULTS

Of the 1047 tPA-eligible ischemic stroke patients, 254 were with PD (baseline mRS 2-5) and 793 were without PD (baseline mRS 0-1). Although PD patients had worse 90-day uw-mRS, higher mortality, more health-care utilization, and worse quality of life than non-disabled patients, 53% returned to at least their baseline mRS, those treated faster had better outcome, and there was no increased bleeding risk. Comparing PD patients treated by MSU versus EMS, 90-day uw-mRS was 0.42 versus 0.36 (p = 0.07) and 57% versus 46% returned to at least their baseline mRS. There was no interaction between disability status and MSU versus EMS group assignment (p = 0.67) for 90-day uw-mRS.

CONCLUSION

PD did not prevent the benefit of faster treatment with tPA in the BEST-MSU study. Our data support inclusion of PD patients in the MSU management paradigm.

Effect of race/ethnicity on arterial recanalization following intravenous thrombolysis in acute ischemic stroke patients

INTRODUCTION

Several reports have identified that clinical outcomes such as death or disability in acute ischemic stroke (AIS) patients following intravenous (IV) tissue plasminogen activator (tPA) treatment can vary according to race and ethnicities. We determined the effect of race/ethnicity on rates of arterial recanalization in AIS patients with large vessel occlusion (LVO) after IV tPA.

METHODS

We analyzed 234 patients with LVO detected on computed tomographic angiography (CTA) who received IV tPA and subsequently underwent angiography for potential thrombectomy. The primary occlusion sites on CTA and digital subtracted angiography (DSA) were compared and a score was given to the level of recanalization with values ranging from 1 (complete recanalization), 2 (partial recanalization), or 3 (no recanalization).The effect of race/ethnicity were assessed for predicting vessel recanalization using the covariates of age, gender, time since stroke onset, tPA dose received, NIHSS (National Institute of Health Stroke Scale) score at baseline, and location of the occlusion, using logistic regression analysis.

RESULTS

Five patients (2.1%) were Hispanic or Latino, 8 (3.4%) Asian, 24 (10.3%) African American, and 197 (84.2%) White. A total of 50% had a distal ICA/proximal M1 occlusion, 20% distal M1 occlusion, and 16% single M2 occlusion. At the primary occlusion site, 44 (18.8%) had complete recanalization on post IV tPA angiogram, 17 (7.3%) had partial recanalization, and 165 (70.5%) had no recanalization. We did not find any association between race/ethnicity and vessel recanalization post IV tPA (Nonwhite combined [OR=1.49, p=0.351]; Asian [OR=1.460, p=0.650]; African American [OR=1.508, p=0.415]; White [OR=0.672, p=0.351]; ethnicity (Hispanic or Latino) [OR= 1.008, p=0.374]); Occlusion location (OR=0.189, p<0.001). Final TICI scores and mRS at 90 days were similar among the different groups.

CONCLUSION

Approximately 19% of patients had complete recanalization after IV tPA, but race and ethnicity did not seem to have an effect on arterial recanalization. Arterial recanalization was only affected by location of occlusion.

Endovascular thrombectomy in acute ischemic stroke patients with prestroke disability (mRS ≥2): A systematic review and meta-analysis

Objective

The effect of endovascular thrombectomy (EVT) in acute ischemic stroke patients with prestroke disability (modified Rankin Scale score, mRS) ≥2) has not been well-studied. This study aimed to assess the safety and benefit of EVT in patients with prestroke disability.

Methods

According to PRISMA guidelines, literature searching was performed using PubMed, Embase, and Cochrane databases, for a series of acute ischemic stroke patients with prestroke mRS ≥2 treated by EVT. Random-effects meta-analysis was used to pool the rate of return to prestroke mRS and mortality at 3-month follow-up.

Results

In total, 13 observational studies, with 2,625 patients, were analyzed. The rates of return to prestroke mRS in patients with prestroke mRS of 2–4 were 20% (120/588), 27% (218/827), and 31% (34/108), respectively. Patients with prestroke disability treated by EVT had a higher likelihood of return to prestroke mRS (relative risk, RR, 1.86; 95% CI 1.28–2.70) and a lower likelihood of mortality (RR 0.75; 95%CI 0.58–0.97) compared with patients with standard medical treatment. Successful recanalization (Thrombolysis in Cerebral Infarction grade 2b-3) after EVT gave a higher likelihood of return to prestroke mRS (RR 2.04; 95% CI 1.17–3.55) and lower mortality (RR 0.72; 95% CI 0.62–0.84) compared with unsuccessful reperfusion.

Conclusions

Acute ischemic stroke patients with prestroke disability may benefit from EVT. Withholding EVT on the sole ground of prestroke disabilities may not be justified.

Systematic Review Registration:https://www.crd.york.ac.uk/prospero/.

Efficacy and safety of mechanical thrombectomy in acute stroke patients with pre-morbid disability

INTRODUCTION –

Patients with pre-morbid disability have been generally excluded from randomized controlled trials of mechanical thrombectomy for acute ischemic stroke. However, stroke physicians commonly encounter such patients in practice, and face challenging treatment decisions when caring for them.

AREAS COVERED –

We review the literature on the safety and efficacy of thrombectomy in patients with pre-morbid disability. Recent clinical-epidemiological studies have highlighted the adverse outcomes that come with each increment of additional post-stroke disability in these patients. Several observational studies - both case series and registry-based studies - have helped demonstrate the comparable safety of thrombectomy in patients with pre-morbid disability as in those without, complementing similar data on thrombolysis. These data also suggest similar rates of successful recanalization, symptomatic intracerebral hemorrhage, and return to pre-stroke level of disability when treated with mechanical thrombectomy, although they have higher mortality.

EXPERT OPINION –

In the absence of high-quality evidence, we recommend pursuing shared decision-making with patients or family members and being upfront about the uncertain evidence. Available observational data underline the potential for a substantial proportion of these patients to return to their pre-morbid state, do not indicate a greater rate of treatment-related complications, and do not support routinely excluding these patients from thrombectomy.