Dual Antiplatelet Treatment up to 72 Hours after Ischemic Stroke

Developing targeted antioxidant nanomedicines for ischemic penumbra: Novel strategies in treating brain ischemia-reperfusion injury

During cerebral ischemia-reperfusion conditions, the excessive reactive oxygen species in the ischemic penumbra region, resulting in neuronal oxidative stress, constitute the main pathological mechanism behind ischemia-reperfusion damage. Swiftly reinstating blood perfusion in the ischemic penumbra zone and suppressing neuronal oxidative injury are key to effective treatment. Presently, antioxidants in clinical use suffer from low bioavailability, a singular mechanism of action, and substantial side effects, severely restricting their therapeutic impact and widespread clinical usage. Recently, nanomedicines, owing to their controllable size and shape and surface modifiability, have demonstrated good application potential in biomedicine, potentially breaking through the bottleneck in developing neuroprotective drugs for ischemic strokes. This manuscript intends to clarify the mechanisms of cerebral ischemia-reperfusion injury and provides a comprehensive review of the design and synthesis of antioxidant nanomedicines, their action mechanisms and applications in reversing neuronal oxidative damage, thus presenting novel approaches for ischemic stroke prevention and treatment.

Beyond RCTs: Short-term dual antiplatelet therapy in secondary prevention of ischemic stroke and transient ischemic attack

BACKGROUND AND PURPOSE

Randomized controlled trials (RCTs) proved the efficacy of short-term dual antiplatelet therapy (DAPT) in secondary prevention of minor ischemic stroke or high-risk transient ischemic attack (TIA). We aimed at evaluating effectiveness and safety of short-term DAPT in real-world, where treatment use is broader than in RCTs.

METHODS

READAPT (REAl-life study on short-term Dual Antiplatelet treatment in Patients with ischemic stroke or Transient ischemic attack) (NCT05476081) was an observational multicenter real-world study with a 90-day follow-up. We included patients aged 18+ receiving short-term DAPT soon after ischemic stroke or TIA. No stringent NIHSS and ABCD2 score cut-offs were applied but adherence to guidelines was recommended. Primary effectiveness outcome was stroke (ischemic or hemorrhagic) or death due to vascular causes, primary safety outcome was moderate-to-severe bleeding. Secondary outcomes were the type of ischemic and hemorrhagic events, disability, cause of death, and compliance to treatment.

RESULTS

We included 1920 patients; 69.9% started DAPT after an ischemic stroke; only 8.9% strictly followed entry criteria or procedures of RCTs. Primary effectiveness outcome occurred in 3.9% and primary safety outcome in 0.6% of cases. In total, 3.3% cerebrovascular ischemic recurrences occurred, 0.2% intracerebral hemorrhages, and 2.7% bleedings; 0.2% of patients died due to vascular causes. Patients with NIHSS score ⩽5 and those without acute lesions at neuroimaging had significantly higher primary effectiveness outcomes than their counterparts. Additionally, DAPT start >24 h after symptom onset was associated with a lower likelihood of bleeding.

CONCLUSIONS

In real-world, most of the patients who receive DAPT after an ischemic stroke or a TIA do not follow RCTs entry criteria and procedures. Nevertheless, short-term DAPT remains effective and safe in this population. No safety concerns are raised in patients with low-risk TIA, more severe stroke, and delayed treatment start.

Ticagrelor versus clopidogrel in dual antiplatelet therapy after minor stroke or transient ischemic attack: an updated network meta-analysis

BACKGROUND

Dual antiplatelet therapy (DAPT) with clopidogrel plus aspirin is a well-established practice after a minor stroke or transient ischemic attack (TIA). However, ticagrelor plus aspirin may be an alternative.

AIMS

We systematically searched PubMed, Embase, and Cochrane Central from inception to January 2024. We included randomized controlled trials (RCTs) enrolling adults with acute minor stroke or TIA within 72 hours of the onset of the symptoms.

RESULTS

A total of 8 RCTs were included in our meta-analysis. Ticagrelor plus aspirin (RR, 0.70; 95% CrI 0.52, 0.91) and clopidogrel plus aspirin (RR, 0.79; 95% CrI 0.64, 0.98) were superior to aspirin in preventing stroke recurrence in overall analysis. Excluding studies with dual antiplatelet up to 90 days, ticagrelor plus aspirin was the only strategy that maintained superiority compared with aspirin regarding stroke recurrence (RR, 0.70; 95% CrI 0.51, 0.95) and ischemic stroke (RR, 0.68; 95% CrI 0.47, 0.94). There was no significant difference between treatment groups regarding hemorrhagic stroke, functional disability, and mortality.

CONCLUSIONS

DAPTs were superior to aspirin in preventing recurrence or ischemic stroke. Although no significant difference was observed between DAPTs, ticagrelor plus aspirin may be related to worse major bleeding results, including intracranial bleeding. Ticagrelor plus aspirin is a considerable option for patients after a minor stroke or TIA.

Balloon angiopLasty for intracranial Atherosclerotic minor Stroke/TIA (BLAST): study protocol for a multicenter prospective cohort study

Rationale/Aim

Intracranial atherosclerotic stenosis (ICAS) is a common cause of stroke in Asia and is significantly associated with stroke recurrence. The Balloon angiopLasty for intracranial Atherosclerotic minor Stroke/TIA (BLAST) study aims to evaluate the safety and effectiveness of early submaximal balloon angioplasty (SBA) combined with standard medical therapy vs. standard medical therapy alone in patients with minor stroke or transient ischemic attack (TIA) due to ICAS.

Methods

The BLAST study is a multicenter prospective cohort study which will enroll patients with minor stroke or TIA due to symptomatic ICAS within 1 week of symptom onset from 20 centers in China. Eligible patients will receive either SBA with standard medical therapy or standard medical therapy alone based on the decision of the patient or legal representative. Participants will be followed up for 1 year.

Study outcomes

The primary outcome is a composite of stroke or death within 30 days or ischemic stroke in the culprit artery territory from 30 days to 1 year. Secondary outcomes include stroke or death within 30 days, ischemic stroke in the culprit artery territory from 30 days to 1 year, restenosis rate of the culprit artery at 1 year, and neurological improvement at 90 days (assessed by mRS score). Safety outcomes include intracranial hemorrhage within 30 days and endovascular complications.

Sample size estimate

According to previous studies, the incidence of the composite clinical outcomes is 15% in the group receiving medical therapy alone. We assumed the incidence would decrease to 5% in the SBA combined with the medical therapy group. The target sample size is 416 patients (208 per group), with 90% power and 5% type I error, allowing for a 10% loss to follow-up.

Implications

The BLAST study will provide evidence regarding whether early SBA can reduce stroke recurrence and mortality in patients with minor stroke/TIA due to ICAS compared with medical therapy alone.Clinical trial registration:Clinicaltrials.gov, NCT06014723.

Stroke

Stroke affects up to one in five people during their lifetime in some high-income countries, and up to almost one in two in low-income countries. Globally, it is the second leading cause of death. Clinically, the disease is characterised by sudden neurological deficits. Vascular aetiologies contribute to the most common causes of ischaemic stroke, including large artery disease, cardioembolism, and small vessel disease. Small vessel disease is also the most frequent cause of intracerebral haemorrhage, followed by macrovascular causes. For acute ischaemic stroke, multimodal CT or MRI reveal infarct core, ischaemic penumbra, and site of vascular occlusion. For intracerebral haemorrhage, neuroimaging identifies early radiological markers of haematoma expansion and probable underlying cause. For intravenous thrombolysis in ischaemic stroke, tenecteplase is now a safe and effective alternative to alteplase. In patients with strokes caused by large vessel occlusion, the indications for endovascular thrombectomy have been extended to include larger core infarcts and basilar artery occlusion, and the treatment time window has increased to up to 24 h from stroke onset. Regarding intracerebral haemorrhage, prompt delivery of bundled care consisting of immediate anticoagulation reversal, simultaneous blood pressure lowering, and prespecified stroke unit protocols can improve clinical outcomes. Guided by underlying stroke mechanisms, secondary prevention encompasses pharmacological, vascular, or endovascular interventions and lifestyle modifications.

Deep Learning-Based Automatic Classification of Ischemic Stroke Subtype Using Diffusion-Weighted Images

BACKGROUND AND PURPOSE

Accurate classification of ischemic stroke subtype is important for effective secondary prevention of stroke. We used diffusion-weighted image (DWI) and atrial fibrillation (AF) data to train a deep learning algorithm to classify stroke subtype.

METHODS

Model development was done in 2,988 patients with ischemic stroke from three centers by using U-net for infarct segmentation and EfficientNetV2 for subtype classification. Experienced neurologists (n=5) determined subtypes for external test datasets, while establishing a consensus for clinical trial datasets. Automatically segmented infarcts were fed into the model (DWI-only algorithm). Subsequently, another model was trained, with AF included as a categorical variable (DWI+AF algorithm). These models were tested: (1) internally against the opinion of the labeling experts, (2) against fresh external DWI data, and (3) against clinical trial dataset.

RESULTS

In the training-and-validation datasets, the mean (±standard deviation) age was 68.0±12.5 (61.1% male). In internal testing, compared with the experts, the DWI-only and the DWI+AF algorithms respectively achieved moderate (65.3%) and near-strong (79.1%) agreement. In external testing, both algorithms again showed good agreements (59.3%-60.7% and 73.7%-74.0%, respectively). In the clinical trial dataset, compared with the expert consensus, percentage agreements and Cohen's kappa were respectively 58.1% and 0.34 for the DWI-only vs. 72.9% and 0.57 for the DWI+AF algorithms. The corresponding values between experts were comparable (76.0% and 0.61) to the DWI+AF algorithm.

CONCLUSION

Our model trained on a large dataset of DWI (both with or without AF information) was able to classify ischemic stroke subtypes comparable to a consensus of stroke experts.

Dual Antiplatelet Therapy for the Acute Management and Long-term Secondary Prevention of Ischemic Stroke and Transient Ischemic Attack, An Updated Review

To improve the efficacy over antiplatelet monotherapy, dual antiplatelet therapy (DAPT) has been increasingly adopted in the management of non-cardioembolic stroke. For minor ischemic stroke and high-risk transient ischemic attack, the aspirin-clopidogrel combination is now recommended for acute short-term treatment, whereas aspirin-ticagrelor combination may be considered in selected patients, especially those with resistance to clopidogrel. For long-term stroke prevention, aspirin-dipyridamole combination has been used as an alternative to antiplatelet monotherapy, and aspirin or clopidogrel combined with cilostazole may be prescribed for added protection in high-risk patients. In this paper, we review the development of DAPT from a historical perspective and describe the findings from major clinical trials published up until the end of 2023. Using the 2021 American Heart Association guideline for secondary stroke prevention as a basis for our recommendations, we further discuss areas of controversy and more recent developments to provide an updated review for clinicians to consider in their daily practice.