Low-dose versus standard-dose alteplase in acute ischemic stroke in Asian stroke registries: an individual patient data pooling study

Comparing Low- or Standard-Dose Alteplase in Endovascular Thrombectomy: Insights From a Nationwide Registry

BACKGROUND

Timely intravenous thrombolysis and endovascular thrombectomy are the standard reperfusion treatments for large vessel occlusion stroke. Currently, it is unknown whether a low-dose thrombolytic agent (0.6 mg/kg alteplase) can offer similar efficacy to the standard dose (0.9 mg/kg alteplase).

METHODS

We enrolled consecutive patients in the multicenter Taiwan Registry of Endovascular Thrombectomy for Acute Ischemic Stroke who had received combined thrombolysis (within 4.5 hours of onset) and thrombectomy treatment from January 2019 to April 2023. The choice of low- or standard-dose alteplase was based on the physician's discretion. The outcomes included successful reperfusion (modified Thrombolysis in Cerebral Infarction score, 2b-3), symptomatic intracerebral hemorrhage, 90-day modified Rankin Scale score, and 90-day mortality. The outcomes between the 2 groups were compared using multivariable logistic regression and inverse probability of treatment weighting-adjusted analysis.

RESULTS

Among the 2242 patients in the Taiwan Registry of Endovascular Thrombectomy for Acute Ischemic Stroke, 734 (33%) received intravenous alteplase. Patients in the low-dose group (n=360) were older, had more women, more atrial fibrillation, and longer onset-to-needle time compared with the standard-dose group (n=374). In comparison to low-dose alteplase, standard-dose alteplase was associated with a lower rate of successful reperfusion (81% versus 87%; adjusted odds ratio, 0.63 [95% CI, 0.40-0.98]), a numerically higher incidence of symptomatic intracerebral hemorrhage (6.7% versus 3.9%; adjusted odds ratio, 1.81 [95% CI, 0.88-3.69]), but better 90-day modified Rankin Scale score (functional independence [modified Rankin Scale score, 0-2], 47% versus 31%; adjusted odds ratio, 1.91 [95% CI, 1.28-2.86]), and a numerically lower mortality rate (9% versus 15%; adjusted odds ratio, 0.73 [95% CI, 0.43-1.25]) after adjusting for covariates. Similar results were observed in the inverse probability of treatment weighting-adjusted models. The results were consistent across predefined subgroups and age strata.

CONCLUSIONS

Despite the lower rate of successful reperfusion and higher risk of symptomatic intracerebral hemorrhage with standard-dose alteplase, standard-dose alteplase was associated with a better functional outcome in patients receiving combined thrombolysis and thrombectomy.

Best medical management versus intravenous thrombolysis for mild non-disabling ischemic stroke: A prospective noninferiority registry study

OBJECTIVES

The efficacy and safety of intravenous thrombolysis uncertain in patients with non-disabling mild ischemic stroke. Our aim was to investigate whether best medical management only is noninferior to intravenous thrombolysis plus best medical management therapy for achieving favorable functional outcome at 90 days.

MATERIALS AND METHODS

In a prospective acute ischemic stroke registry from 2018 through 2020, 314 non-disabling mild ischemic stroke patients received best medical management only and 638 underwent intravenous thrombolysis plus best medical management. The primary outcome was modified Rankin Scale ≤1 at Day 90. The noninferiority margin was -5%. Secondary outcomes of hemorrhagic transformation, early neurologic deterioration and mortality were also evaluated.

RESULTS

The best medical management only was noninferior to the combined therapy of intravenous thrombolysis and best medical management with regard to the primary outcome (unadjusted risk difference, 1.16%; 95% CI, -3.48% ∼ 5.8%; p = 0.0046 for noninferiority; adjusted risk difference, 3.01%; 95% CI, -3.39% ∼ 9.41%). After propensity score matching, p < 0.0001 for noninferiority. RD, 4.03%; 95% CI, -1.59% ∼ 9.69%. p < 0.0001 for noninferiority. Adjusted RD, 5.23%; 95% CI, -1.88% ∼ 9.97%. The occurrence of hemorrhagic transformation was significantly increased in the group of combination therapy (OR, 4.26; 95% CI, 1.30 to 13.99; p = 0.008), while no significant difference was detected in early neurologic deterioration (OR, 1.11; 95% CI, 0.49-2.52; p = 0.808) and mortality (OR, 0.57; 95% CI, 0.20 to 1.69; p = 0.214) between groups.

CONCLUSIONS

In the present study, we found the best medical management only was noninferior to the combination therapy of intravenous thrombolysis plus best medical management for non-disabling mild ischemic stroke within 4.5 h after onset. Best medical management may be a treatment of choice for non-disabling mild ischemic stroke patients. Further randomized controlled studies are warranted.

Comparing performance measures and clinical outcomes between mobile stroke units and usual care in underserved areas

BACKGROUND

The efficacy of mobile stroke units (MSUs) in improving acute ischemic stroke (AIS) care in developing countries is unknown. We compared performance measures and stroke outcomes in AIS patients between MSU and usual care: emergency medical services (EMS) and walk-in.

METHODS

We enrolled patients > 18 years of age with an AIS within 4.5 h after onset. Demographic data, types, and time of reperfusion therapies and clinical outcomes were recorded. A favorable outcome was defined as a modified Rankin Scale (mRS) 0-2 at 3 months.

RESULTS

A total of 978 AIS patients (MSU = 243, EMS = 214, walk-in = 521) were enrolled between June 1, 2018, and April 30, 2021. The mean age (± SD) was 66 (± 14) years, and 510 (52.1%) were male. AIS time metrics were the shortest in the MSU with a mean (± SD) door to needle (DN) time of 20 (± 7), 29 (± 13), and 35 (± 16) min (p < 0.001) and door to puncture (DP) time of 73 ± 19, 86 ± 33, and 101 ± 42 min (p < 0.001) in MSU, EMS, and walk-in, respectively. Participants in the MSU (56.8%) received higher rate of reperfusion therapie(s) when compared to the EMS (51.4%) and walk-in (31.5%) (p < 0.001). After adjustment for any potential confounders and using the EMS as a reference, the MSU has the highest likelihood of achieving a favorable outcome (adjusted OR 2.15; 95% CI 1.39-3.32).

CONCLUSIONS

In underserved populations, MSUs significantly reduced DN time, increased the likelihood of receiving reperfusion treatment, and achieved independency at 3 months when compared to usual care.

Comparison of Effectiveness and Safety of Low-Dose Versus Standard-Dose Intravenous Recombinant Tissue Plasminogen Activator in Patients With Acute Ischemic Stroke: A Meta-Analysis

The aim of the present meta-analysis is to compare the efficacy and safety of low-dose and standard-dose recombinant tissue plasminogen activators (r-tPA) in patients with acute ischemic stroke. The present meta-analysis was conducted according to the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines. We conducted a systematic search in PubMed, Embase, and the Cochrane Library to identify studies published between January 1, 2010, and January 31, 2023, using the following terms: "stroke," "alteplase," "doses," "efficacy," "tissue plasminogen activator," "r-tPA," and "safety." Primary efficacy outcomes included favorable outcomes (Modified Rankin Scale scores of 0-2), while secondary efficacy outcome was all-cause mortality at 90 days. Safety outcomes included asymptomatic intracerebral hemorrhage (ICH) and symptomatic ICH assessed using the National Institute of Neurological Disorders and Stroke (NINDS) study and the Safe Implementation of Thrombolysis in Stroke-Monitoring (SITS-MOST) study. We also compared parenchymal hematomas as safety outcome between the two groups defined by the authors themselves in their research. A total of 16 studies were included in the present meta-analysis. The meta-analysis did not report any significant difference between low-dose and standard-dose r-tPA in terms of mortality, symptomatic intracranial hemorrhage (SICH), asymptomatic ICH, and parenchymal hematomas. However, the favorable outcome was significantly greater in patients receiving a standard dose of r-tPA.

Low-dose vs. standard-dose intravenous alteplase for acute ischemic stroke with unknown time of onset

Background

Standard-dose intravenous alteplase for acute ischemic stroke (AIS) in the unknown or extended time window beyond 4.5 h after symptom onset is both effective and safe for certain patients who were selected based on multimodal neuroimaging. However, uncertainty exists regarding the potential benefit of using low-dose alteplase among the Asian population outside the 4.5-h time window.

Methods

Consecutive AIS patients who received intravenous alteplase between 4.5 and 9 h after symptom onset or with an unknown time of onset guided by multimodal computed tomography (CT) imaging were identified from our prospectively maintained database. The primary outcome was excellent functional recovery, defined as having a modified Rankin scale (mRS) score of 0-1 at 90 days. Secondary outcomes included functional independence (an mRS score of 0-2 at 90 days), early major neurologic improvement (ENI), early neurologic deterioration (END), any intracranial hemorrhage (ICH), symptomatic ICH (sICH), and 90-day mortality. Propensity score matching (PSM) and multivariable logistic regression models were used to adjust for confounding factors and compare the clinical outcomes between the low- and standard-dose groups.

Results

From June 2019 to June 2022, a total of 206 patients were included in the final analysis, of which 143 were treated with low-dose alteplase and 63 were treated with standard-dose alteplase. After accounting for confounding factors, we observed that there were no statistically significant differences between the standard- and low-dose groups with respect to excellent functional recovery [adjusted odds ratio = 1.22 (aOR), 95% confidence interval (CI): 0.62-2.39; adjusted rate difference (aRD) = 4.6%, and 95% CI: -11.2 to 20.3%]. Patients of both groups had similar rates of functional independence, ENI, END, any ICH, sICH, and 90-day mortality. In the subgroup analysis, patients aged ≥70 years were more likely to achieve excellent functional recovery when receiving standard-dose rather than low-dose alteplase.

Conclusion

The effectiveness of low-dose alteplase might be comparable to that of standard-dose alteplase in AIS patients aged <70 years with favorable perfusion-imaging profiles in the unknown or extended time window but not in those aged ≥70 years. Furthermore, low-dose alteplase did not significantly reduce the risk of sICH compared to standard-dose alteplase.

Low-dose vs. standard-dose alteplase for Chinese patients with acute ischemic stroke: A propensity score analysis

Background and purpose

Previous studies have stimulated debates on low-dose alteplase administration in acute ischemic stroke (AIS) among the Asian population. We sought to evaluate the safety and efficacy of low-dose alteplase in Chinese patients with AIS using a real-world registry.

Methods

We analyzed data from the Shanghai Stroke Service System. Patients receiving alteplase intravenous thrombolysis within 4.5 hours were included. These patients were divided into the low-dose alteplase group (0.55-0.65 mg/kg) and the standard-dose alteplase group (0.85-0.95 mg/kg). Baseline imbalances were adjusted by using the propensity score matching. The primary outcome was mortality or disability, which was defined as the modified Rankin scale (mRS) score ranging from 2 to 6 at discharge. The secondary outcomes were in-hospital mortality, symptomatic intracranial hemorrhage (sICH) and functional independence (mRS score 0-2).

Results

From January 2019 to December 2020, a total of 1,334 patients were enrolled and 368 (27.6%) were treated with low-dose alteplase. The median age of the patients was 71 years, and 38.8% were female. Our study showed that the low-dose group had significantly higher rates of death or disability (adjusted odds ratio (aOR) = 1.49, 95% confidence interval (CI) [1.12, 1.98]) and less functional independence (aOR = 0.71, 95%CI [0.52, 0.97]) than the standard-dose group. There was no significant difference in sICH or in-hospital mortality between the standard-dose and low-dose alteplase groups.

Conclusions

Low-dose alteplase was related to a poor functional outcome without lowering the risk of sICH, compared with standard-dose alteplase for AIS patients in China.

Different Doses of Intravenous Tissue-Type Plasminogen Activator for Acute Ischemic Stroke: A Network Meta-Analysis

Background

This study aims to assess the efficacy and safety of different doses of intravenous tissue-type plasminogen activator (tPA) for acute ischemic stroke (AIS) by adopting a network meta-analysis (NMA).

Methods

Studies comparing different doses of tPA in AIS were identified by retrieving electronic databases. NMAs of outcome measures included favorable functional outcome with a modified Rankin scale score (mRS) of 0 or 1 at 3 months after treatment (3M-FF), the functional independence with a mRS of 0, 1, or 2 at 3 months (3M-FI), symptomatic intracranial hemorrhage (sICH) and 3-month all-cause mortality (3M-M). Symptomatic intracranial hemorrhage (sICH) and 3-month all-cause mortality (3M-M) were assessed. Probability-based ranking and surface under cumulative ranking (SUCRA) were performed to identify the best dose of tPA. Inconsistency was evaluated by node-splitting analysis and a loop-specific approach. Publication bias was analyzed by funnel plots.

Results

A total of 14 studies were included in the quantitative synthesis. The NMA results revealed no difference among low (<0.7 mg/kg), moderate (0.8 mg/kg), and standard (0.9 mg/kg) doses of tPA with regard to efficacy and safety. The SUCRAs of 3M-FF and 3M-FI showed that the standard dose ranked first, the moderate dose ranked second, and the low dose ranked third. The SUCRA of sICH showed that the standard dose ranked first (78.1%), the low dose ranked second (61.0%), and the moderate dose ranked third (11.0%). The SUCRAs of 3-month mortality showed that the standard dose ranked first (73.2%), the moderate dose ranked second (40.8%), and the low dose ranked third (36.1%). No significant inconsistency was shown by node-splitting analysis and no publication bias was shown in funnel plots.

Conclusion

Lower dose tPA was comparable to the standard dose with regard to efficacy and safety. Based on the SUCRA results and American Heart Association/American Stroke Association (AHA/ASA) guidelines, the standard dose was still the optimal selection for AIS.

The End of Tissue-Type Plasminogen Activator's Reign?

Mechanical thrombectomy is a highly effective treatment for acute ischemic stroke caused by large-vessel occlusion in the anterior cerebral circulation, significantly increasing the likelihood of recovery to functional independence. Until recently, whether intravenous thrombolysis before mechanical thrombectomy provided additional benefits to patients with acute ischemic stroke-large-vessel occlusion remained unclear. Given that reperfusion is a key factor for clinical outcome in patients with acute ischemic stroke-large-vessel occlusion and the efficacy of both intravenous thrombolysis and mechanical thrombectomy is time-dependent, achieving complete reperfusion with a single pass should be the primary angiographic goal. However, it remains undetermined whether extending the procedure with additional endovascular attempts or local lytics administration safely leads to higher reperfusion grades and whether there are significant public health and cost implications. Here, we outline the current state of knowledge and research avenues that remain to be explored regarding the consistent therapeutic benefit of intravenous thrombolysis in anterior circulation strokes and the potential place of adjunctive intra-arterial lytics administration, including alternative thrombolytic agent place.

Effectiveness of Standard-Dose vs. Low-Dose Alteplase for Acute Ischemic Stroke Within 3-4.5 h

Background

The efficacy and safety of intravenous alteplase administered 3–4.5 h after acute ischemic stroke have been demonstrated. However, whether responses differ between low-dose and standard-dose alteplase during this time window and whether certain subgroups benefit more remain unknown.

Patients and Methods

The current analysis was based on a multicenter matched-cohort study conducted in Taiwan. The treatment group comprised 378 patients receiving intravenous alteplase 3–4.5 h after stroke onset, and the control group comprised 378 age- and sex-matched patients who did not receive alteplase treatment during the same period. Standard- and low-dose alteplase was administered to patients at the physician's discretion.

Results

Overall, patients receiving alteplase exhibited more favorable outcomes than did controls [34.0 vs. 22.7%; odds ratio (OR): 1.75, 95% confidence interval (CI): 1.27–1.42], and the effectiveness was consistent in all subgroups. Although patients in the standard-dose group (n = 182) were younger than those in the low-dose (n = 192) group, the proportions of patients with favorable outcomes (36.3 vs. 31.8%; OR: 1.22, 95% CI: 0.80–1.88) and symptomatic hemorrhage (2.8 vs 4.2%; OR: 0.65, 95% CI: 0.21–2.02) were consistently comparable in a covariate-adjusted model and an age-matched cohort. In the subgroup analysis, patients with cardioembolism, atrial fibrillation, and hypercholesterolemia were more likely to achieve favorable outcomes after receiving standard-dose than low-dose alteplase.

Conclusion

In the 3–4.5 h time window, the effectiveness and safety of standard-dose and low-dose alteplase may be comparable. A standard dose may be selected for patients with cardioembolism, atrial fibrillation, or hypercholesterolemia.

Off-label use of intravenous thrombolysis for acute ischemic stroke: a critical appraisal of randomized and real-world evidence

Intravenous thrombolysis (IVT) represents the only systemic reperfusion therapy able to reverse neurological deficit in patients with acute ischemic stroke (AIS). Despite its effectiveness in patients with or without large vessel occlusion, it can be offered only to a minority of them, because of the short therapeutic window and additional contraindications derived from stringent but arbitrary inclusion and exclusion criteria used in landmark randomized controlled clinical trials. Many absolute or relative contraindications lead to disparities between the official drug label and guidelines or expert recommendations. Based on recent advances in neuroimaging and evidence from cohort studies, off-label use of IVT is increasingly incorporated into the daily practice of many stroke centers. They relate to extension of therapeutic time windows, and expansion of indications in co-existing conditions originally listed in exclusion criteria, such as use of alternative thrombolytic agents, pre-treatment with antiplatelets, anticoagulants or low molecular weight heparins. In this narrative review, we summarize recent randomized and real-world data on the safety and efficacy of off-label use of IVT for AIS. We also make some practical recommendations to stroke physicians regarding the off-label use of thrombolytic agents in complex and uncommon presentations of AIS or other conditions mimicking acute cerebral ischemia. Finally, we provide guidance on the risks and benefits of IVT in numerous AIS subgroups, where equipoise exists and guidelines and treatment practices vary.