Using Tenecteplase for Acute Ischemic Stroke: What Is the Hold Up?

Episode Care Costs Following Catheter-Directed Reperfusion Therapies for Pulmonary Embolism: A Literature-Based Comparative Cohort Analysis

This analysis aimed to estimate 30-day episode care costs associated with 3 contemporary endovascular therapies indicated for treatment of pulmonary embolism (PE). Systematic literature review was used to identify clinical research reporting costs associated with invasive PE care and outcomes for ultrasound-accelerated thrombolysis (USAT), continuous-aspiration mechanical thrombectomy (CAMT), and volume-controlled-aspiration mechanical thrombectomy (VAMT). Total episode variable care costs were defined as the sum of device costs, variable acute care costs, and contingent costs. Variable acute care costs were estimated using methodology sensitive to periprocedural and postprocedural resource allocation unique to the 3 therapies. Contingent costs included expenses for thrombolytics, postprocedure bleeding events, and readmissions through 30 days. Through February 28, 2023, 70 sources were identified and used to inform estimates of 30-day total episode variable costs. Device costs for USAT, CAMT, and VAMT were the most expensive single component of total episode variable costs, estimated at $5,965, $10,279, and $11,901, respectively. Costs associated with catheterization suite utilization, intensive care, and hospital length of stay, along with contingent costs, were important drivers of total episode costs. Total episode variable care costs through 30 days were $19,146, $20,938, and $17,290 for USAT, CAMT, and VAMT, respectively. In conclusion, estimated total episode care costs after invasive treatment for PE are heavily influenced by device expense, in-hospital care, and postacute care complications. Regardless of device cost, strategies that avoid thrombolytics, reduce the need for intensive care unit care, shorten length of stay, and reduce postprocedure bleeding and 30-day readmissions contributed to the lowest episode costs.

Split intein-mediated backbone cyclization enhances the stability and activity of staphylokinase, a potent fibrin-selective plasminogen activator

Staphylokinase (Sak), a small 15 kDa globular protein that is secreted by certain strains of Staphylococcus aureus, shows a potent fibrin-selective thrombolytic activity. Earlier work has shown that Sak could potentially become a low-cost alternative to currently used thrombolytic agents, such as tissue plasminogen activator (tPA). In attempts to improve its potential for clinical applications, numerous modifications of Sak have already been investigated. Here, we have characterized a novel Sak modification, cyclized Sak (cyc-Sak), which was prepared through split-intein mediated protein backbone cyclization. We have characterized the structure, stability and the activity of cyc-Sak using biophysical techniques, limited proteolysis studies and plasminogen (PG)-activation assays. Our results show that cyc-Sak possesses an identical structure, enhanced stability, resistance to proteolysis by exoproteases and improved PG-activation properties compared to its linear counterpart. It can be over-expressed with high yield in the cytoplasm of Escherichia coli and is easily purified in a two-step process. The intein-mediated cyclization occurs spontaneously in vivo during protein expression and does not necessitate further modification steps after purification of the protein. Furthermore, covalent Sak cyclization could be readily combined with other Sak modifications previously proposed, to generate an effective thrombolytic agent with lower immunogenicity and improved stability and activity.

Comparison of pharmacokinetic properties of alteplase and tenecteplase. The future of thrombolysis in acute ischemic stroke

INTRODUCTION

The drug most frequently used for thrombolysis in cases of acute ischemic stroke (AIS) is alteplase. However, there is moderate-to-high-quality evidence that tenecteplase has similar or higher efficacy and safety. With improved pharmacokinetic properties over alteplase, tenecteplase could be a significant advantage in treating AIS.

AREAS COVERED

After conducting an extensive search on Scopus and PubMed, this manuscript reviews and compares the pharmacokinetic properties of alteplase and tenecteplase. Additionally, it provides information on pharmacodynamics, clinical efficacy, safety, tolerability, and drug-drug interactions.

EXPERT OPINION

The pharmacokinetic profile of alteplase and tenecteplase is derived from studies in patients with acute myocardial infarction. Thanks to its pharmacokinetic properties, tenecteplase is the drug closest to being the ideal fibrinolytic for AIS. Its longer half-life enables a single-bolus administration, which is particularly useful in emergencies. Tenecteplase has proven to have a good efficacy and safety profile in randomized clinical trials. Although we are awaiting the results of the ongoing phase 3 randomized clinical trials, we believe that tenecteplase has the potential to revolutionize the treatment of AIS through thrombolysis.

Tenecteplase Versus Alteplase for Acute Stroke: Mortality and Bleeding Complications

STUDY OBJECTIVE

Intravenous thrombolysis with alteplase has been the foundation of initial treatment of acute ischemic stroke for several decades. Tenecteplase is a thrombolytic agent that offers logistical advantages in cost and administration relative to alteplase. There is evidence that tenecteplase has at least similar efficacy and safety outcomes compared with alteplase for stroke. In this study, we compared tenecteplase versus alteplase for acute stroke in a large retrospective US database (TriNetX) regarding the following 3 outcomes: (1) mortality, (2) intracranial hemorrhage, and (3) the need for acute blood transfusions.

METHODS

In this retrospective study using the US cohort of 54 academic medical centers/health care organizations in the TriNetX database, we identified 3,432 patients treated with tenecteplase and 55,894 patients treated with alteplase for stroke after January 1, 2012. Propensity score matching was performed on basic demographic information and 7 previous clinical diagnostic groups, resulting in a total of 6,864 patients with acute stroke evenly matched between groups. Mortality rates, the frequency of intracranial hemorrhage, and blood transfusions (as a marker of significant blood loss) were recorded for each group over the ensuing 7- and 30-day periods. Secondary subgroup analyses were conducted on a cohort treated from 2021 to 2022 in an attempt to determine whether temporal differences in acute ischemic stroke treatment would alter the results.

RESULTS

Patients treated with tenecteplase had a significantly lower mortality rate (8.2% versus 9.8%; risk ratio [RR], 0.832) and lower risk of major bleeding as measured by the frequency of blood transfusions (0.3% versus 1.4%; RR, 0.207) than alteplase at 30 days after thrombolysis for stroke. In the larger 10-year data set of patients with stroke treated after January 1, 2012, patients receiving tenecteplase were not found to have a statistically different incidence of intracranial hemorrhage (3.5% versus 3.0%; RR, 1.185) at 30 days after the administration of the thrombolytic agents in patients. However, a subgroup analysis of 2,216 evenly matched patients with stroke treated from 2021 to 2022 demonstrated notably better survival and statistically lower rates of intracranial hemorrhage than the alteplase group.

CONCLUSION

In our large retrospective multicenter study using real-world evidence from large health care organizations, tenecteplase for the treatment of acute stroke demonstrated a lower mortality rate, decreased intracranial hemorrhage, and less significant blood loss. The favorable mortality and safety profiles observed in this large study, taken together with previous randomized controlled trial data and operational advantages in rapid dosing and cost-effectiveness, all support the preferential use of tenecteplase in patients with ischemic stroke.

Tenecteplase versus alteplase before mechanical thrombectomy: experience from a US healthcare system undergoing a system-wide transition of primary thrombolytic

BACKGROUND

Tenecteplase (TNK) is a genetically modified variant of alteplase (TPA) and has been established as a non-inferior alternative to TPA in acute ischemic stroke (AIS). Whether TNK exerts distinct benefits in large vessel occlusion (LVO) AIS is still being investigated.

OBJECTIVE

To describe our first-year experience after a healthcare system-wide transition from TPA to TNK as the primary thrombolytic.

METHODS

Patients with AIS who received intravenous thrombolytics between January 2020 and August 2022 were retrospectively reviewed. All patients with LVO considered for mechanical thrombectomy (MT) were included in this analysis. Spontaneous recanalization (SR) after TNK/TPA was a composite variable of reperfusion >50% of the target vessel territory on cerebral angiography or rapid, significant neurological recovery averting MT. Propensity score matching (PSM) was performed to compare SR rates between TNK and TPA.

RESULTS

A total of 148 patients were identified; 51/148 (34.5%) received TNK and 97/148 (65.5%) TPA. The middle cerebral arteries M1 (60.8%) and M2 (29.7%) were the most frequent occlusion sites. Baseline demographics were comparable between TNK and TPA groups. Spontaneous recanalization was significantly more frequently observed in the TNK than in the TPA groups (unmatched: 23.5% vs 10.3%, P=0.032). PSM substantiated the observed SR rates (20% vs 10%). Symptomatic intracranial hemorrhage, 90-day mortality, and functional outcomes were similar.

CONCLUSIONS

The preliminary experience from a real-world setting demonstrates the effectiveness and safety of TNK before MT. The higher spontaneous recanalization rates with TNK are striking. Additional studies are required to investigate whether TNK is superior to TPA in LVO AIS.

A Systematic Review of the Efficacy and Safety of Tenecteplase Versus Streptokinase in the Management of Myocardial Infarction in Developing Countries

Myocardial infarction (MI) is a significant cause of morbidity and mortality in low- and middle-income countries. Fibrinolytic agents and percutaneous coronary intervention (PCI) are the main approaches for the recanalization and reperfusion of the myocardium following MI. Many studies have shown that PCI is superior to thrombolytics due to better outcomes and decreased mortality. Nevertheless, PCI's mortality gain over thrombolysis decreases as the time between presentation and PCI procedure increases. Furthermore, PCI is not widely available in most developing countries; thus, it cannot be delivered promptly. Most patients in developing countries cannot afford the cost of PCI. Thus, thrombolytic therapy remains essential to managing MI in developing countries and should not be disregarded. Tenecteplase (TNK) and streptokinase (SK) are the two most widely used fibrinolytics in managing MI in underdeveloped nations. Despite their widespread availability, comparative studies on them have been inconclusive. This study aims to review the available literature on the effectiveness and safety of TNK versus SK in managing MI in resource-poor nations. The study is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) extension and analyzed according to Cochrane guidelines on synthesis without meta-analysis. A comprehensive literature search for studies comparing TNK and STK was conducted on EMBASE, Cochrane Library, Web of Science, CINAHL, Scopus, Google Scholar, and Ovid version of MEDLINE databases. A reference list of the eligible articles and systematic reviews was also screened. A narrative synthesis of the available data was done by representing the data on the effect direction plot, followed by vote counting. Of the 2284 references retrieved from the databases, only 17 studies met the inclusion criteria and were selected for final analysis. The study suggested that TNK is more effective in complete ST-segment resolution (80% vs 10% on the effect direction plot) and symptom relief (80% vs 20%) than SK. SK and TNK were comparable in achieving successful fibrinolysis (50% vs 50%). For the safety parameters, TNK is associated with a lesser risk of major bleeding than SK (88.9% vs 11.1%) and minor bleeding (25% vs 75%). SK was linked with a higher risk of hypotension/shock (77.8% vs 11.1%) and anaphylaxis/allergy (100% vs 0%). Long-term mortality was higher in the SK arm (100% vs 0%). In-hospital mortality is comparable between the two agents (37.5% vs 37.5%). There is conflicting evidence regarding other safety and efficacy endpoints. Compared to SK, TNK results in better complete ST-segment resolution and symptom relief. A higher risk of long-term mortality, increased risk of major and minor bleeding, hypotension, and allergy/anaphylaxis was observed in patients who received SK. Both agents were comparable in terms of in-hospital mortality and successful fibrinolysis. Controversy exists regarding which agent is linked with increased risk of 30-35-day mortality benefit and stroke. Randomized controlled trials (RCTs) with large sample sizes are needed to establish TNK vs SK superiority in efficacy and safety. The long-term duration of follow-up of the mortality rate of the two agents is also essential, as most patients in these regions cannot afford the recommended PCI post-fibrinolysis.

Thrombus composition and thrombolysis resistance in stroke

A State of the Art lecture titled "Thrombus Composition and Thrombolysis Resistance in Stroke" was presented at the ISTH Congress in 2022. Intravenous thrombolysis (IVT) remains the only pharmacologic option to re-establish cerebral perfusion at the acute phase of ischemic stroke. IVT is based on the administration of recombinant tissue plasminogen activator with the objective of dissolving fibrin, the major fibrillar protein component of thrombi. Almost 30 years on from its introduction, although the clinical benefits of IVT have been clearly demonstrated, IVT still suffers from a relatively low efficacy, with a rate of successful early recanalization below 50% overall. Analyses of thrombectomy-recovered acute ischemic stroke (AIS) thrombi have shown that apart from occlusion site, thrombus length, and collateral status, AIS thrombus structure and composition are also important modulators of IVT efficacy. In this article, after a brief presentation of IVT principle and current knowledge on IVT resistance, we review recent findings on how compaction and structural alterations of fibrin together with nonfibrin thrombus components such as neutrophil extracellular traps and von Willebrand factor interfere with IVT in AIS. We further discuss how these new insights could soon result in the development of original adjuvant therapies for improved IVT in AIS. Finally, we summarize relevant new data presented during the 2022 ISTH Congress.

Nanotechnology in Stroke: New Trails with Smaller Scales

Stroke is a leading cause of death, long-term disability, and socioeconomic costs, highlighting the urgent need for effective treatment. During acute phase, intravenous administration of recombinant tissue plasminogen activator (tPA), a thrombolytic agent, and endovascular thrombectomy (EVT), a mechanical intervention to retrieve clots, are the only FDA-approved treatments to re-establish cerebral blood flow. Due to a short therapeutic time window and high potential risk of cerebral hemorrhage, a limited number of acute stroke patients benefit from tPA treatment. EVT can be performed within an extended time window, but such intervention is performed only in patients with occlusion in a larger, anatomically more proximal vasculature and is carried out at specialty centers. Regardless of the method, in case of successful recanalization, ischemia-reperfusion injury represents an additional challenge. Further, tPA disrupts the blood-brain barrier integrity and is neurotoxic, aggravating reperfusion injury. Nanoparticle-based approaches have the potential to circumvent some of the above issues and develop a thrombolytic agent that can be administered safely beyond the time window for tPA treatment. Different attributes of nanoparticles are also being explored to develop a multifunctional thrombolytic agent that, in addition to a thrombolytic agent, can contain therapeutics such as an anti-inflammatory, antioxidant, neuro/vasoprotective, or imaging agent, i.e., a theragnostic agent. The focus of this review is to highlight these advances as they relate to cerebrovascular conditions to improve clinical outcomes in stroke patients.

Analysis of Mortality in Intracerebral Hemorrhage Patients with Hyperacute Ischemic Stroke Treated Using Thrombolytic Therapy: A Nationwide Population-based Cohort Study in South Korea

This study investigated the impact of intracerebral hemorrhage (ICH) on the cumulative mortality of patients with hyperacute ischemic stroke. This population-based retrospective cohort study used claims data from the National Health Insurance Service customized database of South Korea. The recruitment period was 2005−2018. The study population included patients with hyperacute ischemic stroke who had received intravenous thrombolysis. The primary endpoint was 12-month cumulative mortality, which was analyzed in both the ICH and no-ICH groups. Of the 50,550 patients included, 2567 (5.1%) and 47,983 (94.9%) belonged to the ICH and no-ICH groups, respectively. In the univariable analysis for 12-month mortality, ICH patients were substantially more prevalent among dead patients than among patients who survived (11.6% versus 3.6%; p < 0.001). The overall 12-month cumulative mortality rate was 18.8%. Mortality in the ICH group was higher than that in the no-ICH group (42.8% versus 17.5%; p < 0.001). In the multivariable analysis, the risk of 12-month cumulative mortality was 2.97 times higher in the ICH group than in the no-ICH group (95% confidence interval, 2.79−3.16). The risk of 12-month cumulative mortality in hyperacute ischemic stroke can increase approximately threefold after the occurrence of spontaneous ICH following intravenous thrombolysis.

Platelet-targeted thrombolysis for treatment of acute ischemic stroke

Thrombolysis with tissue-type plasminogen activator (tPA) remains the main treatment for acute ischemic stroke. Nevertheless, tPA intervention is limited by a short therapeutic window, low recanalization rates, and a risk of intracranial hemorrhage (ICH), highlighting the clinical demand for improved thrombolytic drugs. We examined a novel thrombolytic agent termed "SCE5-scuPA," comprising a single-chain urokinase plasminogen activator (scuPA) fused with a single-chain antibody (SCE5) that targets the activated glycoprotein IIb/IIIa platelet receptor, for its effects in experimental stroke. SCE5-scuPA was first tested in a whole blood clot degradation assay to show the benefit of platelet-targeted thrombolysis. The tail bleeding time, blood clearance, and biodistribution were then determined to inform the use of SCE5-scuPA in mouse models of photothrombotic stroke and middle cerebral artery occlusion against tenecteplase. The impacts of SCE5-scuPA on motor function, ICH, blood-brain barrier (BBB) integrity, and immunosuppression were evaluated. Infarct size was measured by computed tomography imaging and magnetic resonance imaging. SCE5-scuPA enhanced clot degradation ex vivo compared with its nonplatelet-targeting control. The maximal SCE5-scuPA dose that maintained hemostasis and a rapid blood clearance was determined. SCE5-scuPA administration both before and 2 hours after photothrombotic stroke reduced the infarct volume. SCE5-scuPA also improved neurologic deficit, decreased intracerebral blood deposits, preserved the BBB, and alleviated immunosuppression poststroke. In middle cerebral artery occlusion, SCE5-scuPA did not worsen stroke outcomes or cause ICH, and it protected the BBB. Our findings support the ongoing development of platelet-targeted thrombolysis with SCE5-scuPA as a novel emergency treatment for acute ischemic stroke with a promising safety profile.

Tenecteplase vs. alteplase for acute ischemic stroke: a systematic review

INTRODUCTION

Thrombolysis for acute ischemic stroke (AIS) with alteplase is the currently approved therapy for patients who present within 4.5 h of symptom onset and meet criteria. Recently, there has been interest in the thrombolytic tenecteplase, a modified version of alteplase, due to its lower cost, ease of administration, and studies reporting better outcomes when compared to alteplase. This systematic review compares the efficacy of tenecteplase vs. alteplase with regard to three outcomes: (1) rate of symptomatic hemorrhage, (2) functional outcome at 90 days, and (3) reperfusion grade after thrombectomy to compare the efficacy of both thrombolytics in AIS METHODS: The search was conducted in August 2021 in PubMed, filtered for randomized controlled trials, and studies in English. The main search term was "tenecteplase for acute stroke."

RESULTS

A total of 6 randomized clinical trials including 1675 patients with AIS was included. No one's study compared alteplase to tenecteplase with all three outcomes after acute ischemic stroke; however, by using a combination of the results, this systematic review summarizes whether tenecteplase outperforms alteplase.

CONCLUSIONS

The available evidence suggests that tenecteplase appears to be a better thrombolytic agent for acute ischemic stroke when compared to alteplase.

CE: Acute Ischemic Stroke

ABSTRACT

Stroke, the most common form of cerebrovascular disease, is a leading cause of death and disability throughout the world. There have been no significant advances in the development of effective therapeutics for hemorrhagic stroke, and for ischemic stroke highly effective, evidence-based therapies such as alteplase and mechanical thrombectomy are widely underutilized. Improving outcomes for patients experiencing ischemic stroke requires faster recognition and appropriate intervention within the treatment window (the first 24 hours after symptom onset). This article discusses the pathophysiology underlying the various types of ischemic stroke; the risk factors for ischemic stroke; stroke presentation; and the evidence-based treatments, nursing assessments, and monitoring protocols that are critical to patient recovery.

Thrombus Composition and Efficacy of Thrombolysis and Thrombectomy in Acute Ischemic Stroke

Thrombi retrieved from patients with acute ischemic stroke are highly heterogeneous. Recent data suggest that thrombus composition may impact on mechanical thrombectomy, the number of recanalization manoeuvres, resistance to retrieval, and on thrombolytic potential. Our aim was to summarize evidence describing the impact of thrombus composition on efficacy of mechanical thrombectomy and thrombolysis in patients with acute ischemic stroke. The scoping review methodology guided by the Joanna Briggs Institute, an adaption of the Arksey and O'Malley, was followed. Comprehensive searches were conducted in MEDLINE, EMBASE, SCOPUS, and Web of Science. Articles were classified into 4 key themes: (1) composition of stroke thrombi, (2) thrombus composition and mechanical thrombectomy, (3) thrombus composition and thrombolytic therapy, and (4) novel imaging and endovascular approaches. Our search identified 698 articles published from 1987 to June 2020. Additional articles were extracted from reference lists of the selected articles. Overall, 95 topic-specific articles identified for inclusion published in 40 different journals were included. Reports showed that thrombus composition in stroke was highly heterogeneous, containing fibrin, platelets, red blood cells, VWF (von Willebrand Factor), and neutrophil extracellular traps. Thrombi could roughly be divided into fibrin- and red blood cell-rich clots. Fibrin-rich clots were associated with increased recanalization manoeuvres, longer procedure time, and less favorable clinical outcomes compared with red blood cell-rich clots. Advances in detection or treatment of thrombi that take into account clot heterogeneity may be able to improve future endovascular and thrombolytic treatment of stroke.

Advancement of Biomaterial-Based Postoperative Adhesion Barriers

Postoperative peritoneal adhesion (PPA) is a prevalent incidence that generally happens during the healing process of traumatized tissues. It causes multiple severe complications such as intestinal obstruction, chronic abdominal pain, and female infertility. To prevent PPA, several antiadhesion materials and drug delivery systems composed of biomaterials are used clinically, and clinical antiadhesive is one of the important applications nowadays. In addition to several commercially available materials, like film, spray, injectable hydrogel, powder, or solution type have been energetically studied based on natural and synthetic biomaterials such as alginate, hyaluronan, cellulose, starch, chondroitin sulfate, polyethylene glycol, polylactic acid, etc. Moreover, many kinds of animal adhesion models, such as cecum abrasion models and unitary horn models, are developed to evaluate new materials' efficacy. A new animal adhesion model based on hepatectomy and conventional animal adhesion models is recently developed and a new adhesion barrier by this new model is also developed. In summary, many kinds of materials and animal models are studied; thus, it is quite important to overview this field's current progress. Here, PPA is reviewed in terms of the species of biomaterials and animal models and several problems to be solved to develop better antiadhesion materials in the future are discussed.

Acute ischemic stroke management: concepts and controversies.A narrative review

INTRODUCTION

Amongst the 25.7 million survivors and 6.5 million deaths from stroke between 1990 and 2013, ischemic strokes accounted for approximately 70% and 50% of the cases, respectively. With patients still suffering from complications and stroke recurrence, more questions have been raised as to how we can better improve patient management.

AREAS COVERED

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and Newcastle-Ottawa Scale (NOS) were adopted to ensure a comprehensive inclusion of quality literature from various sources. PubMed and Embase were searched for evidence on thrombolysis, mechanical thrombectomy, artificial intelligence (AI), antiplatelet therapy, anticoagulation and hypertension management.

EXPERT OPINION

The directions of future research in these areas are dependent on the current level of validation. Endovascular therapy and applications of AI are relatively new compared to the other areas discussed in this review. As such, future studies need to focus on validating their efficacy. As for thrombolysis, antiplatelet and anticoagulation therapy, their efficacy has been well-established and future research efforts should be directed toward adjusting its use according to patient-specific factors, starting with factors with the most clinical relevance and prevalence.