Influence of time to endovascular stroke treatment on outcomes in the early versus extended window paradigms

Mode of Onset Modifies the Effect of Time to Endovascular Reperfusion on Clinical Outcomes after Acute Ischemic Stroke: An Analysis of the DAWN Trial

OBJECTIVE

We aimed to assess the impact of time to endovascular thrombectomy (EVT) on clinical outcomes in the DAWN trial, while also exploring the potential effect modification of mode of stroke onset on this relationship.

METHODS

The association between every 1-h treatment delay with 90-day functional independence (modified Rankin Scale [mRS] score 0-2), symptomatic intracranial hemorrhage, and 90-day mortality was explored in the overall population and in three modes of onset subgroups (wake-up vs. witnessed vs. unwitnessed).

RESULTS

Out of the 205 patients, 98 (47.8%) and 107 (52.2%) presented in the 6 to 12 hours and 12 to 24 hours time window, respectively. Considering all three modes of onset together, there was no statistically significant association between time last seen well to randomization with either functional independence or mortality at 90 days in either the endovascular thrombectomy (mRS 0-2 1-hour delay OR 1.07; 95% CI 0.93-1.24; mRS 6 OR 0.84; 95% CI 0.65-1.03) or medical management (mRS 0-2 1-hour delay OR 0.98; 95% CI 0.80-1.14; mRS 6 1-hour delay OR 0.94; 95% CI 0.79-1.09) groups. Moreover, there was no significant interaction between treatment effect and time (p = 0.439 and p = 0.421 for mRS 0-2 and 6, respectively). However, within the thrombectomy group, the models that tested the association between time last seen well to successful reperfusion (modified Treatment in Cerebral Infarction ≥2b) and 90-day functional independence showed a significant interaction with mode of presentation (p = 0.013). This appeared to be driven by a nominally positive slope for both witnessed and unwitnessed strokes versus a significantly (p = 0.018) negative slope in wake-up patients. There was no association between treatment times and symptomatic intracranial hemorrhage.

INTERPRETATION

Mode of onset modifies the effect of time to reperfusion on thrombectomy outcomes, and should be considered when exploring different treatment paradigms in the extended window. ANN NEUROL 2024.

Stroke imaging modality for endovascular therapy in the extended window: systematic review and meta-analysis

BACKGROUND

In anterior circulation large vessel occlusion (LVO) in the extended time window, the guidelines recommend advanced imaging (ADVI) to select patients for endovascular therapy (EVT). However, questions remain regarding its availability and applicability in the real world. It is unclear whether an approach to the extended window EVT that does not use ADVI would be equivalent.

METHODS

In April 2022, a literature search was performed to identified randomized controlled trials (RCT) and observational studies describing 90-day outcomes. We performed a meta-analysis of the proportion of aggregate using a random effect to estimate rates of functional independence, defined as modified Rankin Scale (mRS) score ≤2 at 90 days, mean mRS, mortality and symptomatic intracranial hemorrhage (sICH) stratified by imaging modality.

RESULTS

Four RCTs and 28 observational studies were included. The pooled proportion of functional independence among patients selected by ADVI was 44% (95% CI 39% to 48%; I2=80%) and 48% (95% CI 41% to 55%; I2=75%) with non-contrast CT/CT angiography (NCCT/CTA) (p=0.36). Mean mRS with ADVI was 2.88 (95% CI 2.36 to 3.41; I2=0.0%) and 2.79 (95% CI 2.31 to 3.27; I2=0.0%) with NCCT (p=0.79). Mortality in patients selected by ADVI was 13% (95% CI 10% to 17%; I2=81%) and 16% (95% CI 12% to 22%; I2=69%) with NCCT (p=0.29). sICH with ADVI was 4% (95% CI 3% to 7%; I2=73%) and 6% with NCCT/CTA (95% CI 4% to 8%; I2=6%, p=0.27).

CONCLUSIONS

Our study suggests that, in anterior circulation LVO, the rates of functional independence may be similar when patients are selected using ADVI or NCCT for EVT in the extended time window. A simplified triage protocol does not seem to increase mortality or sICH. PROTOCOL REGISTRATION NUMBER: (PROSPERO ID: CRD42021236092).

Association between time to treatment and clinical outcomes in endovascular thrombectomy beyond 6 hours without advanced imaging selection

BACKGROUND

The effectiveness and safety of endovascular thrombectomy (EVT) in the late window (6-24 hours) for acute ischemic stroke (AIS) patients selected without advanced imaging is undetermined. We aimed to assess clinical outcomes and the relationship with time-to-EVT treatment beyond 6 hours of stroke onset without advanced neuroimaging.

METHODS

Patients who underwent EVT selected with non-contrast CT/CT angiography (without CT perfusion or MR imaging), between October 2015 and March 2020, were included from a national stroke registry. Functional and safety outcomes were assessed in both early (<6 hours) and late windows with time analyzed as a continuous variable.

RESULTS

Among 3278 patients, 2610 (79.6%) and 668 (20.4%) patients were included in the early and late windows, respectively. In the late window, for every hour delay, there was no significant association with shift towards poorer functional outcome (modified Rankin Scale (mRS)) at discharge (adjusted common OR 0.98, 95% CI 0.94 to 1.01, p=0.27) or change in predicted functional independence (mRS ≤2) (24.5% to 23.3% from 6 to 24 hours; aOR 0.99, 95% CI0.94 to 1.04, p=0.85). In contrast, predicted functional independence was time sensitive in the early window: 5.2% reduction per-hour delay (49.4% to 23.5% from 1 to 6 hours, p=0.0001). There were similar rates of symptomatic intracranial hemorrhage (sICH) (3.4% vs 4.6%, p=0.54) and in-hospital mortality (12.9% vs 14.6%, p=0.33) in the early and late windows, respectively, without a significant association with time.

CONCLUSION

In this real-world study, there was minimal change in functional disability, sICH and in-hospital mortality within and across the late window. While confirmatory randomized trials are needed, these findings suggest that EVT remains feasible and safe when performed in AIS patients selected without advanced neuroimaging between 6-24 hours from stroke onset.

Impact of Time to Treatment on Endovascular Thrombectomy Outcomes in the Early Versus Late Treatment Time Windows

BACKGROUND

The impact of time to treatment on outcomes of endovascular thrombectomy (EVT) especially in patients presenting after 6 hours from symptom onset is not well characterized. We studied the differences in characteristics and treatment timelines of EVT-treated patients participating in the Florida Stroke Registry and aimed to characterize the extent to which time impacts EVT outcomes in the early and late time windows.

METHODS

Prospectively collected data from Get With the Guidelines-Stroke hospitals participating in the Florida Stroke Registry from January 2010 to April 2020 were reviewed. Participants were EVT patients with onset-to-puncture time (OTP) of ≤24 hours and categorized into early window treated (OTP ≤6 hours) and late window treated (OTP >6 and ≤24 hours). Association between OTP and favorable discharge outcomes (independent ambulation, discharge home and to acute rehabilitation facility) as well as symptomatic intracerebral hemorrhage and in-hospital mortality were examined using multilevel-multivariable analysis with generalized estimating equations.

RESULTS

Among 8002 EVT patients (50.9% women; median age [±SD], 71.5 [±14.5] years; 61.7% White, 17.5% Black, and 21% Hispanic), 34.2% were treated in the late time window. Among all EVT patients, 32.4% were discharged home, 23.5% to rehabilitation facility, 33.7% ambulated independently at discharge, 5.1% had symptomatic intracerebral hemorrhage, and 9.2% died. As compared with the early window, treatment in the late window was associated with lower odds of independent ambulation (odds ratio [OR], 0.78 [0.67-0.90]) and discharge home (OR, 0.71 [0.63-0.80]). For every 60-minute increase in OTP, the odds of independent ambulation reduced by 8% (OR, 0.92 [0.87-0.97]; P<0.001) and 1% (OR, 0.99 [0.97-1.02]; P=0.5) and the odds of discharged home reduced by 10% (OR, 0.90 [0.87-0.93]; P<0.001) and 2% (OR, 0.98 [0.97-1.00]; P=0.11) in the early and late windows, respectively.

CONCLUSIONS

In routine practice, just over one-third of EVT-treated patients independently ambulate at discharge and only half are discharged to home/rehabilitation facility. Increased time from symptom onset to treatment is significantly associated with lower chance of independent ambulation and ability to be discharged home after EVT in the early time window.

Association of time to groin puncture with patient outcome after endovascular therapy stratified by etiology

Background

Randomized clinical trials and large stroke registries have demonstrated a time-dependent benefit of endovascular treatment (EVT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). The aim of this study was to investigate whether this could be applied to different stroke subtypes in a real-world single-center cohort.

Materials and methods

Consecutive ischemic stroke patients with LVOs presenting within 24 h after symptom onset were prospectively registered and retrospectively assessed. Baseline multimodal imaging was conducted before EVT. Independent predictors of functional independence [90-day modified Rankin scale (mRS), 0–2] and any incidence of intracranial hemorrhage (ICH) were explored using a stepwise logistic regression model in the entire cohort and in stroke subtypes.

Results

From 2015 to 2020, 140 eligible patients received EVT, of whom 59 (42%) were classified as large artery atherosclerosis (LAA)-related. Time from last known normal to groin puncture was identified as an independent predictor for functional independence in patients of cardioembolic (CE) subtype [odds ratio (OR) 0.90 per 10 min; 95% CI 0.82–0.98; P = 0.013] but not in the LAA subtype and the whole cohort. Groin puncture within 6 h after the time of last known normal was associated with a lower risk of any ICH in the whole cohort (OR 0.36, 95% CI 0.17–0.75, P = 0.007). Sensitivity analysis of patients with complete imaging profiles also confirmed the above findings. Besides, compared with patients of the CE subtype, the LAA subtype had a smaller baseline ischemic core volume, a better collateral status, a slower core growth rate, and a numerically smaller final infarct volume.

Conclusion

Faster groin puncture has a more pronounced effect on the functional outcome in patients of CE subtype than those of LAA subtype. Reducing time to groin puncture is of great importance in improving the prognosis of patients after EVT, especially those of CE subtype, and reducing the incidence of any ICH in all patients.

Characterizing Fast and Slow Progressors in Anterior Circulation Large Vessel Occlusion Strokes

BACKGROUND AND PURPOSE

Infarct growth rate (IGR) in acute ischemic stroke is highly variable. We sought to evaluate impact of symptom-reperfusion time on outcomes in patients undergoing mechanical thrombectomy (MT).

METHODS

A prospectively maintained database from January,2012-August,2020 was reviewed. All patients with isolated MCA-M1 occlusion who achieved complete reperfusion(mTICI2C-3), had a witnessed symptom onset and follow-up MRI were included. IGR was calculated as final infarct volume (FIV)(ml)/symptom onset to reperfusion time(hours) and was dichotomized according to the median value into slow-(SP) versus fast-progressors (FP). The primary analysis aimed to evaluate the impact of symptom-reperfusion time on 90-day mRS in SP and FP. Secondary analysis was performed to identify predictors of IGR.

RESULTS

A total of 137 patients were eligible for analysis. Mean age was 63 ± 15.4 years and median IGR was 5.13ml/hour. SP(n = 69) had higher median ASPECTS, lower median rCBF<30% lesion volume, higher proportion of favorable collaterals and hypoperfusion intensity ratio (HIR)<0.4, higher minimal mean arterial blood pressure before reperfusion, and lower rates of general anesthesia compared to FP(n = 68). Symptom-reperfusion time was comparable between both groups. SP had higher rates of 90-day mRS0-2(71.9%vs.38.9%,aOR;7.226,95%CI[2.431-21.482],p < 0.001) and lower median FIV. Symptom-reperfusion time was associated with 90-day mRS0-2 in FP (aOR;0.541,95%CI[0.309-0.946],p = 0.03) but not in SP (aOR;0.874,95%CI[0.742-1.056],p = 0.16). On multivariable analysis, high ASPECTS and favorable collaterals in the NCCT/CTA model, and low rCBF<30% and HIR<0.4 in the CTP model were independent predictors of SP.

CONCLUSIONS

The impact of symptom-reperfusion time on outcomes significantly varies across slow-versus fast-progressors. ASPECTS, collateral score, rCBF<30%, and HIR define stroke progression profile.

Clinical and Non-Clinical Determinants of the Effect of Mechanical Thrombectomy and Post-Stroke Functional Status of Patients in Short and Long-Term Follow-Up

To date, inconsistent results evaluating the effect of parameters on mechanical thrombectomy (MT) outcomes in stroke-patients have been published. This study aimed to identify the key parameters for functional status after MT in stroke-patients in short and long-term follow-up.

METHOD

The study analysis focused on the relevance of selected clinical and non-clinical parameters to the functional status of the patients after MT.

RESULTS

417 stroke-patients (mean age 67.8 ± 13.2 years) were qualified. Atrial fibrillation, and leukocytosis were significant for the neurological status on the first day of stroke (p = 0.036, and p = 0.0004, respectively). The parameters with the strongest effect on the functional status on day 10 were: age (p = 0.009), NIHSS (p = 0.002), hyperglycemia (p = 0.009), the result in TICI (p = 0.046), and first pass effect (p = 0.043). The parameters with the strongest effect on the functional status on day 365 were: age and NIHSS on the first day of stroke (p = 0.0002 and 0.002, respectively). Leukocytosis and the neurological status at baseline were key parameters associated with ICB after MT (p = 0.007 and p = 0.003, respectively).

CONCLUSIONS

Age and neurological status in the ultra-acute phase of stroke are crucial for the functional status in short and long-term observations of patients treated with mechanical thrombectomy. Atrial fibrillation, hyperglycemia, and inflammatory state are relevant to the short-term post-stroke functional status. First pass effect and the degree of post-interventional reperfusion are important technical parameters to the short-term functional status. Neurological status and white blood count during the acute phase are associated with a high rate of post-procedural intracranial bleeding.