A critical analysis of intra-arterial thrombolytic doses in acute ischemic stroke treatment

Reteplase versus alteplase for acute ischaemic stroke within 4.5 hours (RAISE): rationale and design of a multicentre, prospective, randomised, open-label, blinded-endpoint, controlled phase 3 non-inferiority trial

BACKGROUND AND PURPOSE

Reteplase is the third generation of alternative thrombolytic agent. We hypothesis that reteplase will be non-inferior to alteplase in achieving excellent functional outcome at 90 days among eligible patients with acute ischaemic stroke.

METHODS AND DESIGN

Reteplase versus alteplase for acute ischaemic stroke within 4.5 hours (RAISE) trial is a multicentre, prospective, randomised, open-label, blinded endpoint (PROBE), controlled phase 3 non-inferiority trial. A total of 1412 eligible patients will be randomly assigned to receive either reteplase at a dose of 18 mg+ 18 mg or alteplase 0.9 mg/kg at a ratio of 1:1. An independent data monitoring committee will review the trail's progress and safety data.

STUDY OUTCOMES

The primary efficacy outcome of this study is proportion of individuals attaining an excellent functional outcome, defined as modified Rankin Scale (mRS) 0-1 at 90 days. The secondary efficacy outcomes encompass favourable functional outcome defined as mRS 0-2, major neurological improvement on the National Institutes of Health Stroke Scale, ordinal distribution of mRS and Barthel Index score of at least 95 points at 90 days. The primary safety outcomes are symptomatic intracranial haemorrhage at 36 hours within 90 days.

DISCUSSION

The RAISE trial will provide crucial insights into the selection of thrombolytic agents for stroke thrombolysis.

TRIAL REGISTRATION NUMBER

NCT05295173.

Intracerebral hemorrhage risk after adjunct intraarterial thrombolysis in thrombectomy-treated acute ischemic stroke

BACKGROUND AND PURPOSE

Intraarterial thrombolysis as an adjunct to mechanical thrombectomy is increasingly being considered to enhance reperfusion in acute ischemic stroke patients. Intraarterial thrombolysis may increase the risk of post-thrombectomy intracerebral hemorrhage (ICH) in certain patient subgroups.

METHODS

We analyzed acute ischemic stroke patients treated with mechanical thrombectomy in a multicenter registry. The occurrence of any (asymptomatic and symptomatic) post-thrombectomy ICH was ascertained using standard definition requiring serial neurological examinations and computed tomographic scans acquired within 48 hours of the thrombectomy. We determined the risk of ICH in subgroups defined by clinical characteristics and the use of intravenous (IV) thrombolysis.

RESULTS

A total of 146 (7.5%) patients received intraarterial thrombolysis among 1953 acute ischemic stroke patients who underwent mechanical thrombectomy. The proportion of patients who developed any ICH was 26 (17.8%) and 510 (28.2%) among patients who were and were not treated with intraarterial thrombolysis, respectively (p = .006). The proportion of patients who developed symptomatic ICH was 4 (2.7%) and 30 (1.7%) among patients who were and were not treated with intraarterial thrombolysis, respectively (p = .34). Among patients who received IV thrombolysis (n = 1042), the proportion of patients who developed any ICH was 9 (16.7%) and 294 (30.7%) among patients who were and were not treated with intraarterial thrombolysis, respectively (p = .028). The risk was not different in strata defined by age, gender, location of occlusion, preprocedure National Institutes of Health Stroke Scale score, time interval between symptom onset and thrombectomy, Alberta Stroke Program Early CT Score, systolic blood pressure, and serum glucose concentrations.

CONCLUSIONS

In patients undergoing mechanical thrombectomy, the risk of any ICH and symptomatic ICH was not increased with intraarterial thrombolysis, including in those who had already received IV thrombolytics.

Combined intravenous and intra-arterial thrombolysis in hyperacute cerebral ischemia without significant corresponding vascular occlusion/stenosis: A Preliminary investigation

Objective

In this study, we assessed the efficacy and safety of various thrombolytic treatment protocols in patients with hyperacute cerebral infarction.

Methods

Patients diagnosed with acute ischemic stroke within 6 h of symptom onset and with brain computer tomography angiography confirming the absence of major vessel stenosis or occlusion were eligible for this study. The enrolled patients were subsequently randomized into two groups: all the groups received the standard intravenous thrombolysis treatment with rt-PA (0.9 mg/kg), and the experimental group underwent sequential intra-arterial thrombolysis treatment with alteplase (0.3 mg/kg, with a maximum dose of 22 mg), administered directly into the target vessel via a microcatheter. Both groups were closely monitored for changes in their National Institutes of Health Stroke Scale (NIHSS) score, modified Rankin scale score, hemorrhage rate, all-cause mortality rate, and the rate of favorable outcomes at 90 ± 7 days.

Results

Ninety-four participants were enrolled in this study, with both the control and experimental groups initiating intravenous injection of rt-PA at a median time of 29 min. For the experimental group, the median time for arterial puncture was 123 min. Baseline data for both groups were similar (P > 0.05). Hemorrhagic transformation occurred in 24.47 % (23 patients), with a lower intracranial hemorrhage rate observed in the experimental group compared to the control group (15.2 % vs 33.3 %, P < 0.05). Asymptomatic hemorrhage rates were 8.7 % for the experimental group and 12.5 % for the control group, with no hemorrhage detected in other locations. Post-treatment median NIHSS scores were lower in the experimental group than in the control group (7 vs 9, P < 0.05), but short-term NIHSS scores were similar (P > 0.05). A higher proportion of patients in the experimental group achieved favorable outcomes compared to the control group (87.0 % vs 43.8 %, P < 0.05).

Conclusion

In patients with acute ischemic stroke with an onset time of ≤6 h and no major intracranial vessel occlusion, combining rt-PA intravenous thrombolysis with intra-arterial thrombolysis via a microcatheter might yield superior functional outcomes.

Intra-arterial thrombolysis as adjunct to mechanical thrombectomy in acute ischemic stroke patients in the United States: A case control analysis

BACKGROUND

Although observational studies have reported favorable clinical outcomes associated with intra-arterial thrombolysis as adjunct to mechanical thrombectomy, the cost and length of hospitalization associated with this intervention has not been studied.

METHODS

We analyzed the nationally representative data of the United States data from Nationwide Inpatient Sample (NIS) to compare hospitalization cost and duration in addition to other outcomes in patients receiving (n = 1990) with those not receiving intra-arterial thrombolysis (n = 1990) in acute ischemic stroke patients undergoing mechanical thrombectomy using a case control design matched for age, gender, and presence of aphasia, hemiplegia, neglect, coma/stupor, hemianopsia and dysphagia.

RESULTS

There was no difference in the median hospitalization cost in patients treated with intra-arterial thrombolysis compared with those not treated with intra-arterial thrombolysis: $36,992 [28,361 to 54,336] versus $35,440 [24,383 to 50,438], (regression coefficient 2,485 [-1,947 to 6,917], p = 0.27). There was no difference in the median length of hospitalization in patients treated with intra-arterial thrombolysis compared with those not treated with intra-arterial thrombolysis: 6 days [3 to 10] versus 6 days [4 to 10], (regression coefficient -0.34 [-1.47 to 0.80], p = 0.56). There was no difference in odds of home-discharge (OR 1.02 95%CI 0.72-1.43, p = 0.93) or post-procedural intracranial hemorrhage (OR 1.16 95%CI 0.83-1.64, p = 0.39) between the two groups.

CONCLUSIONS

We did not observe an increase in the cost or length of hospitalization associated with the use of intra-arterial thrombolysis as adjunct to mechanical thrombectomy in acute ischemic stroke patients. If the ongoing randomized clinical trials demonstrate therapeutic efficacy in reducing death or disability, this intervention has a high likelihood of being beneficial overall.

Safety and Angiographic Efficacy of Intra-Arterial Fibrinolytics as Adjunct to Mechanical Thrombectomy: Results from the INFINITY Registry

Background and Purpose

Data on safety and efficacy of intra-arterial (IA) fibrinolytics as adjunct to mechanical thrombectomy (MT) are sparse.

Methods

INtra-arterial FIbriNolytics In ThrombectomY (INFINITY) is a retrospective multi-center observational registry of consecutive patients with anterior circulation large-vessel occlusion ischemic stroke treated with MT and adjunctive administration of IA fibrinolytics (alteplase [tissue plasminogen activator, tPA] or urokinase [UK]) at 10 European centers. Primary outcome was the occurrence of symptomatic intracranial hemorrhage (sICH) according to the European Cooperative Acute Stroke Study II definition. Secondary outcomes were mortality and modified Rankin Scale (mRS) scores at 3 months.

Results

Of 5,612 patients screened, 311 (median age, 74 years; 44.1% female) received additional IA after or during MT (194 MT+IA tPA, 117 MT+IA UK). IA fibrinolytics were mostly administered for rescue of thrombolysis in cerebral infarction (TICI) 0-2b after MT (80.4%, 250/311). sICH occurred in 27 of 308 patients (8.8%), with an increased risk in patients with initial TICI0/1 (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.1 to 5.0 per TICI grade decrease) or in those with intracranial internal carotid artery occlusions (aOR, 3.7; 95% CI, 1.2 to 12.5). In patients with attempted rescue of TICI0-2b and available angiographic follow-up, 116 of 228 patients (50.9%) showed any angiographic reperfusion improvement after IA fibrinolytics, which was associated with mRS ≤2 (aOR, 3.1; 95% CI, 1.4 to 6.9).

Conclusions

Administration of IA fibrinolytics as adjunct to MT is performed rarely, but can improve reperfusion, which is associated with better outcomes. Despite a selection bias, an increased risk of sICH seems possible, which underlines the importance of careful patient selection.

Thrombolysis in Cerebral Infarction 2b Reperfusions: To Treat or to Stop?

In patients undergoing mechanical thrombectomy, achieving complete (Thrombolysis in Cerebral Infarction 3) rather than incomplete successful reperfusion (Thrombolysis in Cerebral Infarction 2b) is associated with better functional outcome. Despite technical improvements, incomplete reperfusion remains the final angiographic result in 40% of patients according to recent trials. As most incomplete reperfusions are caused by distal vessel occlusions, they are potentially amenable to rescue strategies. While observational data suggest a net benefit of up to 20% in functional independence of incomplete versus complete reperfusions, the net benefit of secondary improvement from Thrombolysis in Cerebral Infarction 2b to 3 reperfusion might differ due to lengthier procedures and delayed reperfusion. Current strategies to tackle distal vessel occlusions consist of distal (microcatheter) aspiration, small adjustable stent retrievers, and administration of intra-arterial thrombolytics. While there are promising reports evaluating those techniques, all available studies show relevant limitations in terms of selection bias, single-center design, or nonconsecutive patient inclusion. Besides an assessment of risks associated with rescue maneuvers, we advocate that the decision-making process should also include a consideration of potential outcomes if complete reperfusion would successfully be achieved. These include (1) a futile angiographic improvement (hypoperfused territory is already infarcted), (2) an unnecessary angiographic improvement (the patient would not have developed infarction if no rescue maneuver was performed), and (3) a successful rescue maneuver with clinical benefit. Currently there is paucity of data on how these scenarios can be predicted and the decision whether to treat or to stop in a patient with incomplete reperfusion involves many unknowns. To advance the status quo, we outline current knowledge gaps and avenues of potential research regarding this clinically important question.

Outcomes of endovascular versus intravenous thrombolytic treatment for acute ischemic stroke in dialysis patients

BACKGROUND AND OBJECTIVES

To compare the outcomes of IV thrombolytics (tissue plasminogen activator or tPA) with endovascular treatment (intra-arterial tPA ± mechanical thrombectomy) in dialysis patients who suffered from acute ischemic stroke.

STUDY DESIGN

Observational study.

SETTING AND PARTICIPANTS

Data analysis from Nationwide Inpatient Sample (NIS 2005- 2010) including dialysis patients presenting with acute ischemic stroke, either treated with IV thrombolytics or endovascular treatment.

OUTCOMES

Baseline characteristics, in-hospital complications, and discharge outcomes were compared between the two groups. We determined the effect of endovascular treatment on in-hospital mortality, disability at discharge, and post-thrombolytic intracerebral hemorrhages (ICH) after adjusting for potential confounders using multivariate analysis.

RESULTS

Of the 2 313 dialysis patients with ischemic stroke, 1 398 (60%) received IV thrombolytics and 915 (40%) were treated with endovascular treatment. The in-hospital mortality rate and moderate-to-severe disability were lower in dialysis patients receiving endovascular treatment (7.6% vs. 14.5% p = 0.04) and (30% vs. 52% p = <.0001), respectively. After adjusting for age, gender, and potential confounders, endovascular treatment was associated with lower in-hospital mortality (OR 0.5, 95% CI 0.2-0.9) and moderate-to-severe disability (OR 0.3, 95% CI 0.2-0.5).

CONCLUSIONS

The odds of both in-hospital mortality and moderate to severe disability were lower with endovascular treatment in dialysis patients. Such data support the preferential use of endovascular treatment in this patient population.