Thrombolysis, time-to-treatment and in-hospital outcomes among young adults with ischaemic stroke in China: findings from a nationwide registry study in China

BACKGROUND AND PURPOSE

We aimed to determine whether young adults (<50 years) with acute ischaemic stroke (AIS) are more likely to receive intravenous tissue plasminogen activator (IV tPA) and have shorter time to treatment than older patients with stroke.

METHODS

We analysed data from the Chinese Stroke Center Alliance registry for patients with AIS hospitalised between August 2015 and July 2019. Patients were classified into two groups according to age: young adults (<50 years of age) and older adults (≥50 years of age).

RESULTS

Of 793 175 patients with AIS admitted to 1471 hospitals, 9.1% (71 860) were young adults. Compared with older adults, a higher proportion of young adults received IV tPA among patients without contraindicaitons (7.2% vs 6.1%, adjusted OR (aOR) 1.13, 95% CI 1.10 to 1.17) and among patients without contraindications and with onset-to-door time ≤3.5 hours (23.6% vs 19.3%, aOR 1.20, 95% CI 1.15 to 1.24). We did not observe differences in onset-to-needle time (median hours 2.7 hours) or door-to-needle time (DNT) (median minutes 60 min) between young and older adults. The proportion of DNT ≤30 min, DNT ≤45 min and DNT ≤60 min in young and older IV tPA-treated patients were 16.9% vs 18.8%, 30.2% vs 32.8% and 50.2% vs 54.2%, respectively. Compared with older adults, young adults treated with IV tPA had lower odds of in-hospital mortality (0.5% vs 1.3%, aOR 0.54, 95% CI 0.35 to 0.82) and higher odds of independent ambulation at discharge (61.0% vs 53.6%, aOR 1.15, 95% CI 1.08 to 1.22), and the associations may be partly explained by stroke severity measured by the National Institutes of Health Stroke Scale score.

CONCLUSION

Young adults with AIS were more likely to receive IV tPA than older adults, although there was no difference between the two groups in time to treatment. Compared with older adults, young adults may had better in-hospital outcomes.

Update in the Early Management and Reperfusion Strategies of Patients with Acute Ischemic Stroke

Acute ischemic stroke (AIS) remains a leading cause of death and long-term disability. The paradigms on prehospital care, reperfusion therapies, and postreperfusion management of patients with AIS continue to evolve. After the publication of pivotal clinical trials, endovascular thrombectomy has become part of the standard of care in selected cases of AIS since 2015. New stroke guidelines have been recently published, and the time window for mechanical thrombectomy has now been extended up to 24 hours. This review aims to provide a focused up-to-date review for the early management of adult patients with AIS and introduce the new upcoming areas of ongoing research.

Reperfusion therapies of acute ischemic stroke: potentials and failures

Over the past 20 years, clinical research has focused on the development of reperfusion therapies for acute ischemic stroke (AIS), which include the use of systemic intravenous thrombolytics (alteplase, desmoteplase, or tenecteplase), the augmentation of systemic intravenous recanalization with ultrasound, the bridging of intravenous with intra-arterial thrombolysis, the use of multi-modal approaches to reperfusion including thrombectomy and thromboaspiration with different available retrievers. Clinical trials testing these acute reperfusion therapies provided novel insight regarding the comparative safety and efficacy, but also raised new questions and further uncertainty on the field. Intravenous alteplase (tPA) remains the fastest and easiest way to initiate acute stroke reperfusion treatment, and should continue to be the first-line treatment for patients with AIS within 4.5 h from onset. The use of tenecteplase instead of tPA and the augmentation of systemic thrombolysis with ultrasound are both novel therapeutical modalities that may emerge as significant options in AIS treatment. Endovascular treatments for AIS are rapidly evolving due to technological advances in catheter-based interventions and are currently emphasizing speed in order to result in timely restoration of perfusion of still-salvageable, infarcted brain tissue, since delayed recanalization of proximal intracranial occlusions has not been associated with improved clinical outcomes. Comprehensive imaging protocols in AIS may enable better patient selection for endovascular interventions and for testing multi-modal combinatory strategies.

Towards effective and safe thrombolysis and thromboprophylaxis: preclinical testing of a novel antibody-targeted recombinant plasminogen activator directed against activated platelets

RATIONALE

Fibrinolysis is a valuable alternative for the treatment of myocardial infarction when percutaneous coronary intervention is not available in a timely fashion. For acute ischemic stroke, fibrinolysis is the only treatment option with a very narrow therapeutic window. Clinically approved thrombolytics have significant drawbacks, including bleeding complications. Thus their use is highly restricted, leaving many patients untreated.

OBJECTIVE

We developed a novel targeted fibrinolytic drug that is directed against activated platelets.

METHODS AND RESULTS

We fused single-chain urokinase plasminogen activator (scuPA) to a small recombinant antibody (scFvSCE5), which targets the activated form of the platelet-integrin glycoprotein IIb/IIIa. Antibody binding and scuPA activity of this recombinant fusion protein were on par with the parent molecules. Prophylactic in vivo administration of scFvSCE5-scuPA (75 U/g body weight) prevented carotid artery occlusion after ferric chloride injury in a plasminogen-dependent process compared with saline (P<0.001), and blood flow recovery was similar to high-dose nontargeted urokinase (500 U/g body weight). Tail bleeding time was significantly prolonged with this high dose of nontargeted urokinase, but not with equally effective targeted scFvSCE5-scuPA at 75 U/g body weight. Real-time in vivo molecular ultrasound imaging demonstrates significant therapeutic reduction of thrombus size after administration of 75 U/g body weight scFvSCE5-scuPA as compared with the same dose of a mutated, nontargeting scFv-scuPA or vehicle. The ability of scFvSCE5-scuPA to lyse thrombi was lost in plasminogen-deficient mice, but could be restored by intravenous injection of plasminogen.

CONCLUSIONS

Targeting of scuPA to activated glycoprotein IIb/IIIa allows effective thrombolysis and the potential novel use as a fibrinolytic agent for thromboprophylaxis without bleeding complications.

Comparative efficacy of different acute reperfusion therapies for acute ischemic stroke: a comprehensive benefit-risk analysis of clinical trials

BACKGROUND

Numerous acute reperfusion therapies (RPT) are currently investigated as potential new therapeutic targets in acute ischemic stroke (AIS). We conducted a comprehensive benefit-risk analysis of available clinical studies assessing different acute RPT, and investigated the utility of each intervention in comparison to standard intravenous thrombolysis (IVT) and in relation to the onset-to-treatment time (OTT).

METHODS

A comprehensive literature search was conducted to identify all available published, peer-reviewed clinical studies that evaluated the efficacy of different RPT in AIS. Benefit-to-risk ratio (BRR), adjusted for baseline stroke severity, was estimated as the percentage of patients achieving favorable functional outcome (BRR1, mRS score: 0-1) or functional independence (BRR2, mRS score: 0-2) at 3 months divided by the percentage of patients who died during the same period.

RESULTS

A total of 18 randomized (n = 13) and nonrandomized (n = 5) clinical studies fulfilled our inclusion criteria. IV therapy with tenecteplase (TNK) was found to have the highest BRRs (BRR1 = 5.76 and BRR2 = 6.82 for low-dose TNK; BRR1 = 5.80 and BRR2 = 6.87 for high-dose TNK), followed by sonothrombolysis (BRR1 = 2.75 and BRR2 = 3.38), while endovascular thrombectomy with MERCI retriever was found to have the lowest BRRs (BRR1 range, 0.31-0.65; BRR2 range, 0.52-1.18). A second degree negative polynomial correlation was detected between favorable functional outcome and OTT (R (2) value: 0.6419; P < 0.00001) indicating the time dependency of clinical efficacy of all reperfusion therapies.

CONCLUSION

Intravenous thrombolysis (IVT) with TNK and sonothrombolysis have the higher BRR among investigational reperfusion therapies. The combination of sonothrombolysis with IV administration of TNK appears a potentially promising therapeutic option deserving further investigation.

eNOS and stroke: prevention, treatment and recovery

It is common knowledge that ischemic stroke has major social and economic consequences. However, until now, translation of experimental studies into clinical reality has been sorely lacking. So far, most studies have focused on acute stroke outcome and early treatment paradigms affording neuroprotection. It is increasingly recognized that it will be necessary to harness the capacity of the brain for neuroregeneration to improve longer-term outcome. Endothelial nitric oxide synthase (eNOS) is emerging as a key target in molecular stroke research. eNOS ameliorates acute ischemic injury and promotes recovery following cerebral ischemia. This review summarizes the effects of eNOS on the regulation of cerebral blood flow, hemostasis, inflammation, angiogenesis as well as neurogenesis. The possible impact on stroke prevention as well as on strategies aimed at improving long-term stroke outcome are discussed.

Tissue-type plasminogen activator as a therapeutic target in stroke

BACKGROUND

Ischemic stroke is a leading cause of morbidity and mortality worldwide and recombinant human tissue-type plasminogen activator (tPA) is the prominent therapeutic among very few therapeutics used in its treatment. Due to complications attributed to the drug, most notably transformation of ischemia to hemorrhage, tPA is only used in a small number of ischemic stroke cases, albeit significantly more often in specialized stroke centers.

OBJECTIVE

What are the mechanisms of tPA action and side effects in ischemic stroke, and can the knowledge about these mechanisms aid in making tPA a more efficacious and safe therapeutic or in developing alternative therapeutics?

METHODS

tPA use and alternative/combination therapies in acute ischemic stroke treatment are summarized. The review focuses on literature concerning tPA neurotoxicity and its implications for further development of tPA as a stroke therapeutic.

RESULTS/CONCLUSION

Exogenously administered recombinant tPA and endogenous tPA have both turned into promising therapeutic targets for the stroke patient.