The efficacy and safety of endovascular treatment for acute ischemic progressive stroke beyond 24 h

Abstract

Objective

To explore the efficacy and safety of endovascular thrombectomy (EVT) for progressive stroke with large vessel occlusion (LVO) beyond 24 h.

Methods

In this retrospective cohort study, 122 Patients with progressive stroke due to LVO beyond 24 h were selected with Non-Contrast Computed Tomography (NCCT) head, and assigned to the EVT group (n = 61) and the Standard Medical Therapies (SMT) group (n = 61). The proportion of 90-day modified Rankin Scale (mRS) of 0–2, mRS score at discharge and 90-day mRS score, symptomatic intracranial hemorrhage (sICH) and mortality were compared between the two groups. Multivariate regression analysis was performed to assess whether EVT was an independent predictor of clinical outcomes.

Results

No statistically significant differences were observed between the two groups in terms of age, sex distribution, history of hypertension, diabetes, hyperlipidemia, atrial fibrillation, smoking, drinking, National Institutes of Health Stroke Scale (NIHSS) and Alberta Stroke Program Early CT (ASPECTS) scores at admission and at neurological deterioration, proportion of patients receiving intravenous thrombolysis (IVT), arterial occlusion site, discharge disposition or TOAST classification (all P > 0.05). The recanalization rate (modified Thrombolysis in Cerebral Infarction (mTICI) score of 2b–3) of EVT reached 95.1%. Compared with SMT, the proportion of 90-day mRS of 0–2 in the EVT group was higher (60.66% vs. 40.98%, P = 0.046), while they had significantly lower mRS score at discharge (P = 0.003) and 90-day (P = 0.014). Multivariate logistic regression analysis demonstrated that the EVT group was the independent predictor of favorable 90-day outcome (mRS 0–2) (adjusted Odds Ratio (aOR) = 2.29, 95%CI: 1.05–5.12, P = 0.04). In addition, there was no statistical difference in the proportion of sICH (P = 0.119) and 90-day mortality between the two groups (P = 0.178).

Conclusion

The study highlights the safety and effectiveness of EVT in LVO for progressive strokes beyond 24 h based on NCCT head. However, further high quality randomized trials are needed to confirm this finding.

Introduction

Reperfusion therapies, including IVT and EVT, administered in the early phase of acute ischemic stroke (AIS), restore cerebral blood flow and significantly improve neurological function [1, 2]. Five pivotal randomized controlled trials published in 2015 [3–7] established EVT as the cornerstone of AIS management by demonstrating that early restoration of cerebral perfusion via EVT salvages the ischemic penumbra and improves clinical outcomes. Subsequent trials, DAWN [8] and DEFUSE-3 [9], extended the EVT time window to within 24 h of symptom onset using multimodal imaging selection. However, in patients with LVO, neurological deterioration (ND) frequently progresses beyond 24 h and can persist for up to 96 h or longer [10].These patients comprise 5% to 40% of AIS cases [11]. Among patients who experienced ND, 40.1% had poor clinical outcomes at the 90-day follow-up, compared to only 26.4% of patients without ND [12]. Furthermore, the mortality rate among patients with ND was approximately 19% at discharge and increased to 33% by the 90-day follow-up [13]. Numerous therapeutic interventions are currently employed to halt ND, among which revascularization therapy undoubtedly represents one of the most critical approaches. However, for some patients, neurological deterioration occurs beyond the 24-hour time window for EVT. To improve clinical outcomes in patients with progressive stroke, it is particularly important to investigate the efficacy and safety of endovascular therapy beyond the 24-hour time window. Therefore, this study aims to determine the efficacy and safety of EVT for progressive stroke due to LVO presenting beyond 24 h.

Methods

Population and data collection

Four hundred thirty patients presenting with progressive stroke secondary to LVO, admitted to the Department of Neurology at Our Hospital between January 2021 and December 2024, were retrospectively selected. Based on the predefined inclusion and exclusion criteria, a total of 122 patients were ultimately selected. The cohort comprised two groups based on the actual treatment received: 61 patients in the EVT group and 61 patients in the SMT group. This equal distribution of patients between the two treatment arms occurred naturally within the retrospective dataset and was not a result of prospective matching or randomization. In this study, the decision to perform EVT was made non-randomly by the neurointerventional team based on a comprehensive assessment of individual patient factors, including imaging findings, clinical status, and family preferences. The patient screening and inclusion process are summarized in Fig. 1.

Fig. 1.

Patient inclusion and exclusion criteria

Inclusion and Exclusion Criteria for patients with progressive stroke due to LVO beyond 24 h. A total of 139 patients with progressing stroke due to LVO met the inclusion criteria. However, 17 cases were excluded owing to moyamoya disease, hemorrhagic transformation of cerebral infarction, severe comorbidities, or loss to follow-up. Consequently, 122 patients were ultimately selected in the study, with 61 cases assigned to the EVT group and 61 to the SMT group. Abbreviations: Jan, January. Dec, December. n, number of patients or events. h, hour. d, day.

Data extracted from the medical records included demographic information (age and sex), comorbidities (hypertension, diabetes, hyperlipidemia, atrial fibrillation and hyperhomocysteinemia), vascular risk factors (smoking and drinking), clinical and imaging characteristics (NIHSS, mRS, ASPECTS, Transfer, IVT, arterial occlusion site, discharge disposition, TOAST classification). Progressive stroke was defined as ND occurring within 7 days of acute stroke onset, which manifested as an increase in the total NIHSS score by ≥ 4 points or a decline of ≥ 2 points in any of the consciousness, motor function, or language subscales, after the exclusion of secondary causes such as hemorrhage, infection, or metabolic disturbances.

Inclusion Criteria: (1)Clinically confirmed AIS. (a) Patients who were admitted within 24 h of onset, remained clinically stable during the initial hospitalization, but subsequently developed ND after 24 h of hospitalization. (b) ND occurred outside the hospital after stroke onset, and upon arrival, more than 24 h had elapsed since symptom onset. (c) Patients who were hospitalized more than 24 h after onset experienced ND during hospitalization (within 7 days of stroke onset). (2)Age ≥ 18 years; (3)premorbid mRS score ≤ 2; (4)Magnetic Resonance Angiography (MRA) confirmed occlusion of a major anterior or posterior circulation vessel; (5)NCCT ASPECTS [14] for anterior circulation or Posterior Circulation ASPECTS (PC-ASPECTS) [15] at neurological deterioration > 2; (6)ND was defined as the development of any new neurological symptoms within 7 days of acute stroke onset, manifested by an increase in NIHSS score ≥ 4 points or a decline of ≥ 2 points in the consciousness, motor function, or language domains, after the exclusion of secondary causes such as hemorrhage, infection, or metabolic disturbances [16]– [17].

Exclusion Criteria: (1)Intracranial hemorrhage (including intraparenchymal, subarachnoid, subdural/epidural hematoma) or hemorrhagic transformation of cerebral infarction; (2)Cerebral vascular malformations or pathologies (including moyamoya disease, cerebral arteriovenous malformation, dural arteriovenous fistula, and cerebral vasculitis); (3)Severe comorbidities (including malignancy with life expectancy < 6 months, severe cardiac, pulmonary, renal, hepatic insufficiency, coagulopathy and thrombocytopenia); (4)Pregnancy or lactation.

The EVT group and the SMT group

SMT for AIS with LVO consists of internal medicine management with antiplatelet therapy (Clopidogrel 75 mg/day and/or Aspirin 100 mg/day). It also includes conventional medical treatment and standard nursing care for AIS.

EVT was performed under local anesthesia with sedation or general anesthesia. Femoral artery puncture was performed using a modified Seldinger technique. Diagnostic cerebral angiography assessed the occlusion site and collateral circulation. The revascularization strategy (contact aspiration thrombectomy, stent-retriever thrombectomy, or combined techniques) was chosen based on the lesion characteristics. Subsequently, immediate assessment of vascular recanalization was performed via digital subtraction angiography (DSA). For patients identified with underlying arterial stenosis of significant severity, rescue balloon angioplasty and/or stent implantation was conducted. Successful recanalization was defined as mTICI score ≥ 2b.

Outcome assessment

The NCCT ASPECTS of the 122 included patients were independently assessed by two blinded neurologists. Discrepant cases, defined as those with a difference of ≥ 2 in ASPECTS between the two independent raters, or cases with uncertain assessments, were adjudicated by a third senior neurologist.

Trained health managers, who were blinded to group assignment, conducted the 90-day follow-up assessment, which evaluated functional outcomes with the mRS [18] and neurological deficits with the NIHSS [19]. In this study, the primary outcome measure was defined as the proportion of 90-day mRS of 0–2. Secondary outcome measures included the NIHSS score at discharge, the mRS score at discharge, the mRS score at 90 days, the incidence of sICH and mortality. sICH was defined according to the ECASS III criteria [2] as intracranial hemorrhage detected on imaging 24–48 h post-procedure, associated with an increase in NIHSS score ≥ 4 points from baseline or leading to death. In addition, multivariate logistic regression analysis was performed to assess whether EVT was an independent predictor of outcome.

Statistical analysis

Statistical analysis was performed using SPSS 26.0 software. Normally distributed continuous variables are presented as mean and standard deviation and were compared using the independent samples t-test. Non-normally distributed data are reported as median and interquartile range (IQR) and were compared using the Mann-Whitney U test. Categorical variables are described as frequencies and percentages, and comparisons were made using the Chi-square test or Fisher’s exact test. Multivariate logistic regression analysis was used to assess whether receipt of EVT was an independent predictor of outcome. Inter-rater agreement for image classification was evaluated using Cohen’s Kappa statistic. A two-sided P-value < 0.05 was considered statistically significant.

Results

The NCCT ASPECTS of the 122 included patients were independently assessed by two blinded neurologists regarding. The inter-rater agreement was excellent (Kappa = 0.81, P < 0.05).

Characteristics of study population

Of the 61 patients who underwent EVT, the mean age was 62.5 ± 9.4 years, including 44 males (72.1%) and 17 females (27.9%). The median time from onset to groin puncture was 45(IQR 30.83–72) hours. In the EVT group, the distribution of onset-to-puncture times was as follows: 34 cases (55.74%) between > 24 and ≤ 48 h; 14 cases (22.95%) between > 48 and ≤ 72 h; and 13 cases (21.31%) between > 72 h and < 7 days. Among the 61 patients receiving SMT, the mean age was 65.7 ± 9.9 years, with 37 males (60.7%) and 24 females (39.3%). No statistically significant differences were observed between the two groups in terms of age, sex distribution, history of hypertension, diabetes, hyperlipidemia, hyperhomocysteinemia, atrial fibrillation, smoking, drinking, NIHSS and ASPECTS scores at admission and at neurological deterioration, proportion of patients receiving IVT(12 patients received IVT within 4.5 h of stroke onset, either in-hospital or in pre-hospital settings, in accordance with guideline recommendations.), arterial occlusion site(In the EVT group, there were 9 cases of vertebrobasilar artery occlusion, 28 cases of middle cerebral artery (MCA) occlusion, and 24 cases of internal carotid artery (ICA) occlusion, while in the SMT group, there were 12 cases of vertebrobasilar artery occlusion, 1 case of posterior cerebral artery (PCA) occlusion, 30 cases of MCA occlusion, 16 cases of ICA occlusion, and 2 cases of anterior cerebral artery (ACA) occlusion.), discharge disposition or TOAST classification (all P > 0.05), as shown in Table 1.

Table 1.

Baseline characteristics in patients with EVT and SMT

	Total	Endovascular Thrombectomy	Medical Therapies	P valuea
No. of patients	122	61	61
Mean age	64.1 ± 9.7	62.5 ± 9.4	65.7 ± 9.9	0.072
Sex
Male	81(66.4)	44(72.1)	37(60.7)	0.250
Female	41(33.6)	17(27.9)	24(39.3)
History
Smoking	21(17.2)	11(18)	10 (16.4)	1.000
Drinking	5(4.1)	5(8.2)	0 (0.0)	0.068
Hypertension	93(76.2)	48(78.7)	45(73.8)	0.671
Diabetes	38(31.1)	21(34.4)	17(27.9)	0.558
Hyperlipidemia	28(23)	15(24.6)	13(21.3)	0.830
Atrial fibrillation	9(7.4)	7(11.5)	2(3.3)	0.099
Hyperhomocysteinemia	16(13.1)	12(19.7)	4(6.6)	0.060
Transfer	80(65.6)	43(70.5)	37(60.7)	0.341
Intravenous Thrombolysis	12(9.8)	6(9.8)	6(9.8)	1.000
Arterial occlusion site				0.480
Anterior	100(82)	52(85.3)	48(78.7)
Posterior	22(18)	9(14.7)	13(21.3)
NIHSS at Admission(IQR)	6(4–11.75)	7(3–10)	6(4–13)	0.346
NIHSS at Neurologic Deterioration (IQR)	10(7–14.75)	10(6–14)	10(8–15)	0.521
Aspects at Admission				0.074
3–5	18(14.8)	5(8.2)	13(21.3)
6–10	104(85.2)	56(91.8)	48(78.7)
Aspects at Neurologic Deterioration				0.150
3–5	21(17.2)	7(11.5)	14(22.9)
6–10	101(82.8)	54(88.5)	47(77.1)
Toast				0.197
Large Artery Atherosclerosis	109(89.3)	52(85.3)	57(93.4)
Cardioembolism	9(7.4)	6(9.8)	3(4.9)
Other Determined Etiology	4(3.3)	1(1.6)	3(4.9)
Discharge Disposition				0.148
Discharge Home	49(40.16)	23(37.7)	26(42.62)
Transfer to a Rehabilitation Facility	66(54.1)	32(52.46)	34(55.74)
Expired	7(5.74)	6(9.84)	1(1.64)

^a No statistically significant differences in baseline leftacteristics in patients with EVT and SMT(all P > 0.05)

Outcomes

Regarding the surgical approaches for EVT patients: 5 cases (8.2%) underwent direct aspiration, 7 cases (11.5%) received a combination of aspiration and stent retrieval, 49 cases (80.3%) underwent balloon angioplasty and/or stent placement. Balloon angioplasty and/or stent placement was performed in the anterior circulation in 41 cases (83.67%) and in the posterior circulation in 8 cases (16.33%). Post-procedural mTICI scores were: 0-2a in 3 cases (4.9%) and 2b-3 in 58 cases (95.1%).

In terms of efficacy, compared with the SMT group, the EVT group showed a higher proportion of 90-day mRS of 0–2 (60.7% vs. 41%, P = 0.046), as well as better mRS scores at discharge (P = 0.003) and at 90 days (P = 0.014). There were no statistically significant differences between the two groups in the incidence of sICH (9.8% vs.1.6%, P = 0.119) or mortality at 90 days (14.8% vs.26.2%, P = 0.178). Throughout the entire study period, no patient in either group underwent decompressive craniectomy. See Table 2; Fig. 2.

Table 2.

Primary outcome and secondary outcome

	Total	Endovascular Thrombectomy	Medical Therapies	P value
Primary outcome the proportion of 90-day mRS of 0–2	62(50.8)	37(60.7)	25(41)	0.046*
Secondary outcomes
NIHSS at discharge(IQR)a	7.5(4.25–13.75)	6(2–11)	10(6–14)	0.255
mRS at discharge(IQR)	4(3–4)	4(2–4)	4(4–4)	0.003*
90 d mRS(IQR)	2(1–4.75)	2(0–3)	3(1–6)	0.014*
Symptomatic ICHa	7(5.7)	6(9.8)	1(1.6)	0.119
Mortality at 90 daysa	25(20.5)	9(14.8)	16(26.2)	0.178
mTICI score b
0-2a	3(4.9)	3(4.9)	-	-
2b-3	58(95.1)	58(95.1)	-	-
Thrombectomy Method c
Aspiration	5(8.2)	5(8.2)	-	-
Aspiration + Stent retriever	7(11.5)	7(11.5)	-	-
Balloon angioplasty or/and Stent Implantation	15(24.6)	15(24.6)	-	-
Thrombectomy + Balloon angioplasty or/and Stent Implantation	34(55.7)	34(55.7)	-	-

*The EVT group had superior functional outcomes, evidenced by a higher 90-day mRS 0–2 rate and lower mRS scores at discharge and 90 days (all p < 0.05), compared to the SMT group

^a There were no statistically significant differences between the two groups in terms of the NIHSS score at discharge, the incidence of sICH or mortality at 90 days

^b The recanalization rate (mTICI score of 2b–3) of EVT reached 95.1%

^c Proportion of different EVT techniques used

Fig. 2.

Distribution of mRS scores at 90 days comparing EVT group and SMT group

Comparisons of the baseline characteristics presented in Table 1 between the mRS 0–2 and 3–6 groups revealed statistically significant differences in TOAST classification, NIHSS at admission, NIHSS at neurological deterioration, arterial occlusion position and receipt of EVT(P < 0.05). Subsequently, the statistically significant indicators were incorporated into a multivariate regression analysis to determine whether receipt of EVT could independently predict clinical outcomes.

Multivariate logistic regression analysis was performed with the dichotomous outcome (favorable: 90-day mRS 0–2 vs. poor: 90-day mRS 3–6) as the dependent variable. The independent variables included TOAST classification, NIHSS at admission, NIHSS at neurological deterioration, arterial occlusion position and receipt of EVT. The results showed that both the EVT group (aOR = 2.29, 95%CI: 1.05–5.12, P = 0.04) and the admission NIHSS score (aOR = 0.88, 95%CI: 0.8–0.96, P < 0.05) were independent predictors of a favorable 90-day outcome. (mRS 0–2), as shown in Table 3.

Table 3.

Multivariable logistic regression analysis for predicting clinical outcome by EVT for acute ischemic progressive stroke beyond 24 h

	90-day mRS
Variable	OR	95%CI	P
Operative VS non-operative
SMT	Reference
EVT	2.29	1.05–5.12	0.04*
NIHSS at Admission	0.88	0.8–0.96	< 0.01*
NIHSS at Neurologic Deterioration	1.01	0.93–1.12	0.79
Toast
Large Artery Atherosclerosis	Reference
Non-Large Artery Atherosclerosis	0.33	0.09–1.18	0.1
Arterial occlusion position			0.19
Anterior	Reference
Posterior	0.47	0.14–1.43

*EVT for acute ischemic progressive stroke beyond 24 h and NIHSS at admission were independent predictor of functional outcome (P < 0.05)

Discussion

The core finding of the study is for patients with progressive stroke due to LVO who have a pre-procedural NCCT ASPECTS > 2 and an onset-to-treatment time exceeding 24 h, EVT achieved a 95.1% rate of successful recanalization (mTICI 2b-3). Compared to SMT, EVT is likely to improve 90-day neurological functional outcomes without increasing the risks of sICH or mortality.

Currently, Most existing studies on EVT beyond the 24-hour time window rely on the DAWN/DEFUSE-3 imaging evaluation paradigm, which depends on Computed Tomography Perfusion (CTP) or Magnetic Resonance Perfusion (MRP) to assess the mismatch between the ischemic penumbra and the core infarct [20]– [21].A recent multicenter prospective study on thrombectomy beyond the 24-hour time window demonstrated superior clinical outcomes in the thrombectomy group compared to the best medical management group, although this was achieved through the use of advanced imaging techniques for patient selection [22]. However, applying strict perfusion imaging criteria may reduce the proportion of patients eligible for EVT, potentially limiting the treatment’s benefit for the broader population. Furthermore, many hospitals in developing countries lack the specialized software and 24-hour technical support for CTP or MRP, leading to a significant number of stroke patients missing the opportunity for EVT. This study differs from the DAWN/DEFUSE-3 criteria by utilizing a simplified imaging workflow, requiring only a pre-procedural NCCT ASPECTS > 2 for patient selection. This approach aligns with the feasibility of NCCT-based selection proposed by Nguyen et al. [7, 23–25], and demonstrates greater applicability in developing countries, enabling more hospitals without advanced imaging capabilities to perform treatment screening. Moreover, studies such as SELECT2 [26], RESCUE-Japan LIMIT [27], and ANGEL-ASPECT [28] have confirmed that patients with large core infarcts, as assessed by NCCT ASPECTS, can also benefit from EVT. In this study, there were 7 patients with a pre-procedural ASPECTS of 3–5, 6 of whom benefited from EVT. Although the sample size is small, this data suggests that patients with large core infarcts can still derive benefit from EVT even beyond 24 h after onset.

In this study, among the 6 cases of sICH that occurred in the EVT group, 4 (66.67%) underwent intracranial stent placement, and 1 received balloon angioplasty following aspiration thrombectomy. These 5 patients subsequently received dual antiplatelet therapy. These findings suggest that the increased risk of sICH in this study may be associated with rescue stenting and more intensive antithrombotic therapy rather than with thrombectomy itself. This observation indicates that for patients beyond the standard time window, especially when rescue stenting is considered, a careful balance between the benefits of recanalization and the risk of hemorrhage is crucial, and perioperative antithrombotic management should be optimized.

Additionally, this study focused on progressive stroke because the benefit of EVT for patients with LVO presenting with minor symptoms remains controversial [29]– [30]. However, symptom progression often occurs beyond the conventional 24-hour time window, a scenario that more accurately reflects real-world clinical practice. From a pathophysiological perspective, progressive stroke indicates dynamic thrombus extension or collateral failure, which implies that salvageable brain tissue may still exist beyond 24 h and that further neurological deterioration might be halted [31–34]. EVT can salvage such ischemic brain tissue, which is the rationale for selecting patients with progressive stroke in this study and directly contributes to the clinical benefit observed in these patients. In this study, all patients underwent immediate repeat NCCT and vascular imaging upon the occurrence of ND. It was these repeat imaging studies that confirmed the persistence of the original LVO and excluded other causes such as intracranial hemorrhage. By comparing imaging before and after deterioration, this study found no significant worsening in ASPECTS scores at the time of ND compared to baseline in any patient (Table 1), suggesting that infarct expansion was not the cause of neurological decline. We hypothesize that hemodynamic changes leading to failure of compensatory collateral circulation may be the primary mechanism. This provides a theoretical basis for performing EVT beyond 24 h: although symptom onset is delayed, if there is still brain tissue at risk of infarction due to hypoperfusion, timely restoration of blood flow may salvage this tissue, thereby improving neurological outcomes. Unlike other studies on EVT beyond 24 h for progressive stroke [35]– [36], this study did not strictly impose admission or pre-procedural NIHSS score restrictions, as some patients had already experienced neurological deterioration prior to hospitalization, and their baseline NIHSS scores were undocumented. This approach allowed patients with pre-admission ND and higher admission NIHSS scores to undergo EVT, thereby enabling intervention to salvage neurological function. However, our multivariable regression analysis indicated that, in addition to EVT being an independent predictor of a favorable 90-day functional outcome, the NIHSS at admission was also an independent predictor of the 90-day prognosis. The NIHSS at admission OR of 0.88 indicates that a higher NIHSS at admission is associated with a greater likelihood of an unfavorable outcome. This result suggests that in-hospital versus out-of-hospital ND may lead to different clinical outcomes, which also requires further validation in prospective studies.

Certainly, this study has limitations. It was a single-center, retrospective study with a relatively small sample size, which carries a risk of selection bias. Additionally, the primary outcome of this study (proportion of 90-day mRS 0–2, P = 0.046) reached only borderline statistical significance, raising the possibility of a type I error (false-positive). Furthermore, in the multivariable regression analysis, the confidence interval for EVT as a predictor of favorable outcome was wide with its lower limit approaching 1. Nevertheless, we believe the current data still provides a positive preliminary signal supporting the use of EVT in this patient population, for the following reasons. First, in the multivariable logistic regression analysis, EVT treatment remained statistically significant after multivariable adjustment (aOR = 2.29, P = 0.04), which is consistent with the improvement trend observed for the primary outcome in the univariate analysis. Second, secondary outcome measures (the overall distribution of mRS scores at both discharge and 90 days) demonstrated a consistent and statistically significant trend toward improvement that aligned with the primary outcome. Furthermore, no significant differences were observed between the two groups in terms of safety outcomes (rates of symptomatic intracranial hemorrhage and 90-day mortality). In summary, while fully acknowledging the limitations of this study, our findings collectively suggest that EVT holds potential clinical significance and value for patients with LVO stroke who experience ND beyond 24 h from onset. Furthermore, the advantages and disadvantages of the NCCT ASPECTS-based inclusion criteria compared to CTP/MRP-based methods require further validation in larger studies.

Conclusion

Currently, whether patients with LVO beyond the 24-hour time window should undergo EVT remains controversial. There is no unified selection criteria for such patients. Offering EVT to these patients beyond 24 h rely on strict CTP/MRP imaging evaluation, which unfortunately exclude many potential patients. Available evidence suggests that EVT performed after NCCT is likely to be safe and effective. It provides valuable data to support further research on EVT beyond the 24-hour time window. This requires further research through large-scale, multi-center, randomized double-blind clinical trials.

In summary, utilizing NCCT ASPECTS for patient selection, this study demonstratesthe potential value of EVT as a therapeutic intervention for patients with progressive stroke beyond the 24-hour time window.

Authors’ contributions

Author ContributionsConceptualization: Dingan Li; Methodology: Qijin Yu, Jin Jiang; Formal analysis and investigation: Yijun Wang, Chang Chai; Writing-original draft preparation: Yijun Wang, Chang Chai; Writing-review and editing: Heng Wang.

Funding

No funding was received for conducting this study.

Data availability

The data used to support the findings of this study are available from the corresponding author upon request.

Declarations

Ethics approval and consent to participate

This retrospective study was reviewed and approved by the Ethics Committee of Hanzhong Central Hospital. The requirement for written informed consent was waived by the Ethics Committee of Hanzhong Central Hospital due to the retrospective nature of the study design. All procedures were performed in accordance with the 1964 Helsinki Declaration and its later amendments.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.