Alteplase: a review of its use in the management of acute ischaemic stroke

Comparative efficacy and safety of tenecteplase and alteplase in acute ischemic stroke: A pairwise and network meta-analysis of randomized controlled trials

BACKGROUND

Studies on tenecteplase have been yielding mixed results for several important outcomes at different doses, thus hampering objective guideline recommendations in acute ischemic stroke management. This meta-analysis stratifies doses in order to refine our interpretation of outcomes and quantify the benefits and harms of tenecteplase at different doses.

METHODS

PubMed/MEDLINE, the Cochrane Library, and reference lists of the included articles were systematically searched. Several efficacy and safety outcomes were pooled and reported as risk ratios (RRs) with 95% confidence intervals (CIs). Network meta-analysis was used to find the optimal dose of tenecteplase. Meta-regression was run to investigate the impact of baseline NIHSS scores on functional outcomes and mortality.

RESULTS

Ten randomized controlled trials with a total of 4140 patients were included. 2166 (52.32%) patients were enrolled in the tenecteplase group and 1974 (47.68%) in the alteplase group. Tenecteplase at 0.25 mg/kg dose demonstrated significant improvement in excellent functional outcome at 3 months (RR 1.14, 95% CI 1.04-1.26), and early neurological improvement (RR 1.53, 95% CI 1.03-2.26). There was no statistically significant difference between tenecteplase and alteplase in terms of good functional outcome, intracerebral hemorrhage (ICH), symptomatic intracerebral hemorrhage (sICH), and 90-day mortality at any dose. Meta-regression demonstrated superior tenecteplase efficacy with increasing stroke severity, however, the results were statistically nonsignificant.

CONCLUSIONS

Tenecteplase at 0.25 mg/kg dose is more efficacious and at least as safe as alteplase for stroke thrombolysis. Newer analyses need to focus on direct comparison of tenecteplase doses and whether tenecteplase is efficacious at longer needle times.

Thrombolytic Agents: Nanocarriers in Targeted Release

A thrombus, known as a blood clot, may form within the vascular system of the body and impede blood flow. Thrombosis is the most common underlying pathology of cardiovascular diseases, contributing to high morbidity and mortality. However, the main thrombolytic drugs (urokinase, streptokinase, etc.) have shortcomings, including a short half-life, serious side effects and a lack of targeting, that limit their clinical application. The use of nano-drug delivery systems is expected to address these problems and a variety of approaches, including biological and physical responsive systems, have been explored. In this report, recent advances in the development of targeted nano-drug delivery systems are thoroughly reviewed.

Recombinant Tissue Plasminogen Activator Induces Neurological Side Effects Independent on Thrombolysis in Mechanical Animal Models of Focal Cerebral Infarction: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Recombinant tissue plasminogen activator (rtPA) is the only effective drug approved by US FDA to treat ischemic stroke, and it contains pleiotropic effects besides thrombolysis. We performed a meta-analysis to clarify effect of tissue plasminogen activator (tPA) on cerebral infarction besides its thrombolysis property in mechanical animal stroke.

METHODS

Relevant studies were identified by two reviewers after searching online databases, including Pubmed, Embase, and ScienceDirect, from 1979 to 2016. We identified 6, 65, 17, 12, 16, 12 and 13 comparisons reporting effect of endogenous tPA on infarction volume and effects of rtPA on infarction volume, blood-brain barrier, brain edema, intracerebral hemorrhage, neurological function and mortality rate in all 47 included studies. Standardized mean differences for continuous measures and risk ratio for dichotomous measures were calculated to assess the effects of endogenous tPA and rtPA on cerebral infarction in animals. The quality of included studies was assessed using the Stroke Therapy Academic Industry Roundtable score. Subgroup analysis, meta-regression and sensitivity analysis were performed to explore sources of heterogeneity. Funnel plot, Trim and Fill method and Egger's test were obtained to detect publication bias.

RESULTS

We found that both endogenous tPA and rtPA had not enlarged infarction volume, or deteriorated neurological function. However, rtPA would disrupt blood-brain barrier, aggravate brain edema, induce intracerebral hemorrhage and increase mortality rate.

CONCLUSIONS

This meta-analysis reveals rtPA can lead to neurological side effects besides thrombolysis in mechanical animal stroke, which may account for clinical exacerbation for stroke patients that do not achieve vascular recanalization with rtPA.

Determination of Vascular Reactivity of Middle Cerebral Arteries from Stroke and Spinal Cord Injury Animal Models Using Pressure Myography

Stroke and other neurovascular derangements are main causes of global death. They, along with spinal cord injuries, are responsible for being the principal cause of disability due to neurological and cognitive problems. These problems then lead to a burden on scarce financial resources and societal care facilities as well as have a profound effect on patients' families. The mechanism of action in these debilitating diseases is complex and unclear. An important component of these problems arises from derangement of blood vessels, such as blockage due to clotting/embolism, endothelial dysfunction, and overreactivity to contractile agents, as well as alteration in endothelial permeability. Moreover, the cerebro-vasculature (large vessels and arterioles) is involved in regulating blood flow by facilitating auto-regulatory processes. Moreover, the anterior (middle cerebral artery and the surrounding region) and posterior (basilar artery and its immediate locality) regions of the brain play a significant role in triggering the pathological progression of ischemic stroke particularly due to inflammatory activity and oxidative stress. Interestingly, modifiable and non-modifiable cardiovascular risk factors are responsible for driving ischemic and hemorrhagic stroke and spinal cord injury. There are different stroke animal models to examine the pathophysiology of middle cerebral and basilar arteries. In this context, arterial myography offers an opportunity to determine the etiology of vascular dysfunction in these diseases. Herein, we describe the technique of pressure myography to examine the reactivity of cerebral vessels to contractile and vasodilator agents and a prelude to stroke and spinal cord injury.