Recurrent Stroke while on Antiplatelet Therapy

Impact of CYP2C19 Genotype on Efficacy and Safety of Clopidogrel-based Antiplatelet Therapy in Stroke or Transient Ischemic Attack Patients: An Updated Systematic Review and Meta-analysis of Non-East Asian Studies

PURPOSE

Inconclusive and limited results have been reported on the clinical utility of CYP2C19 genotyping in stroke/TIA patients of non-East Asian ancestries. We herein performed an updated systematic review and meta-analysis to quantitatively estimate the association of CYP2C19 loss-of function (LOF) status with efficacy and safety of clopidogrel-based antiplatelet therapy in non-East Asian patients affected by stroke or TIA.

METHODS

A comprehensive search was performed up to July 2023 using PubMed, Web of Knowledge, and Cochrane Library databases. The clinical outcomes investigated were stroke, composite vascular events and bleeding. Pooled estimates were calculated as risk ratios (RR) with 95% CI using the Mantel- Haenszel random-effects model. The quality of evidence was assessed using the GRADEpro tool.

RESULTS

A total number of 1673 stroke/TIA patients from 8 non-East Asian studies, published between 2014 and 2022, were included in the systematic review. Clopidogrel-treated carriers of CYP2C19 LOF alleles were found at increased risk of stroke compared to non-carriers (RR: 1.68, 95%CI: 1.04-2.71, P = 0.03). However, no significant association was observed with the risk of composite vascular events (RR: 1.15, 95%CI: 0.58-2.28, P = 0.69) or bleeding (RR: 0.84, 95%CI: 0.38-1.86, P = 0.67). Similarly, European ancestry patients carrying CYP2C19 LOF alleles displayed a higher risk of stroke (RR: 2.69 (1.11-6.51, P = 0.03), but not of composite vascular events or bleeding.

CONCLUSION

The present updated meta-analysis provides moderate quality evidence of association between CYP2C19 LOF alleles and an increased risk of stroke in non-East Asian patients with stroke/TIA after receiving clopidogrel therapy. Further large pharmacogenetic studies are still warranted to corroborate these findings.

Appropriate use of antiplatelet medications following transient ischemic attacks and stroke: a 9-year study from the Middle East

Background and purpose

Guidelines recommend that patients with high-risk TIAs and minor strokes presenting within 1-3 days from onset should be offered dual antiplatelet therapy (DAPT). There are little data on real-world adherence to these recommendations. We evaluated the appropriateness of DAPT use in TIA and stroke patients in a prospective database.

Methods

The Qatar Stroke Database began the enrollment of patients with TIAs and acute stroke in 2014 and currently has ~16,000 patients. For this study, we evaluated the rates of guideline-adherent use of antiplatelet treatment at the time of discharge in patients with TIAs and stroke. TIAs were considered high-risk with an ABCD2 score of 4, and a minor stroke was defined as an NIHSS of 3. Patient demographics, clinical features, risk factors, previous medications, imaging and laboratory investigations, final diagnosis, discharge medications, and discharge and 90-day modified Rankin Scale (mRS) were analyzed.

Results

After excluding patients with ICH, mimics, and rare secondary causes, 8,082 patients were available for final analysis (TIAs: 1,357 and stroke: 6,725). In high-risk TIAs, 282 of 666 (42.3%) patients were discharged on DAPT. In patients with minor strokes, 1,207 of 3,572 (33.8%) patients were discharged on DAPT. DAPT was inappropriately offered to 238 of 691 (34.4%) low-risk TIAs and 809 of 3,153 (25.7%) non-minor stroke patients.

Conclusion

This large database of prospectively collected patients with TIAs and stroke shows that, unfortunately, despite several guidelines, a large majority of patients with TIAs and stroke are receiving inappropriate antiplatelet treatment at discharge from the hospital. This requires urgent attention and further investigation.

Antiplatelet treatment for acute secondary prevention of non-cardioembolic minor stroke / transient ischaemic attack: an update for the acute physician

Acute stroke is the leading cause of disability in the UK and a leading cause of mortality worldwide. The majority of patients with ischaemic stroke present with minor deficits or transient ischaemic attack (TIA), and are often first seen by patient-facing clinicians. Urgent evaluation and treatment are important as many patients are at high risk of major vascular events and death within hours to days after the index event. This narrative review summarises the evidence on four antiplatelet treatments for non-cardioembolic stroke prevention: aspirin, clopidogrel, dipyridamole and ticagrelor. Each of these drugs has a unique mechanism and has been tested as a single agent or in combination. Aspirin, when given early is beneficial and short-term treatment with aspirin and clopidogrel has been shown to be more effective in high-risk TIA / minor stroke. This review concludes by highlighting gaps in evidence, including scope for future trials that could potentially change clinical practice.

Red blood cell distribution width in different time-points of peripheral thrombolysis period in acute ischemic stroke is associated with prognosis

The relationship between red blood cell distribution width (RDW) in peripheral thrombolysis period and prognosis is not fully clarified in those who underwent intravenous thrombolysis (IVT) for acute ischemic stroke (AIS). Our study aimed to clarify this issue. A retrospective analysis of about 510 consecutive thrombolysis cases for AIS from January 2015 to March 2019 in a single-center database was done and followed-up for 3 months. We used univariate and multivariable models to evaluate the relationship between RDW levels at various time-points after IVT and the occurrence risk of hemorrhagic transformation (HT) and recurrent stroke, and used COX regression to assess the hazard ratios of outcomes with RDW levels. Elevated risk of HT was found in higher tertiles of RDW (OR = 10.282, 95% confidence interval (CI) 2.841–39.209, P < 0.001 in Tp tertile G3; OR = 5.650, 95% CI 1.992–16.025, P = 0.001 in T24 tertile G3; OR = 4.308, 95% CI 1.480–12.542, P = 0.007 in T48 tertile G3 and OR = 6.384, 95% CI 2.201–18.515, P = 0.001 in T72 tertile G3, respectively). Occurrence of recurrent stroke was highest in the RDW tertile G3 (HR = 4.580, 95% CI 2.123–9.883, P < 0.001 in Tp tertile G3; HR = 5.731, 95% CI 2.498–13.151, P = 0.001 in T24 tertile G3; HR = 3.019, 95% CI 1.969–4.059, P = 0.031 in T48 tertile G3; HR = 3.318, 95% CI 1.598–6.890, P = 0.001 in T72 tertile G3, respectively). Mean RDW levels ≥13.60 among AIS patients undergoing thrombolysis was associated with higher risk of HT and recurrent stroke.

Investigational drugs for ischemic stroke: what's in the clinical development pipeline for acute phase and prevention?

INTRODUCTION

Stroke is a leading cause of disability and mortality and its burden expected to increase. The only approved drug for acute ischemic stroke is the intravenous thrombolytic alteplase. The risk of bleeding complications is one of the reasons for the undertreatment of eligible patients. Numerous drugs are currently being developed to improve safety-efficacy.

AREAS COVERED

We reviewed literature from January 1^st, 2000, to 15^th January 2022 for the development and testing of novel drugs with the aim of targeting treatment at prevention of ischemic stroke: PubMed, MEDLINE, Google Scholar, and ClinicalTrial.gov.

EXPERT OPINION

The pathophysiology of ischemic stroke involves multiple pathways causing cerebral artery obstruction and brain tissue ischemia. Data suggest that tenecteplase is a more promising fibrinolytic agent with a superior efficacy-safety profile, compared to the currently approved alteplase. Current guidelines consider a short-term cycle of mannitol or hypertonic saline to be advisable in patients with space-occupying hemispheric infarction. Regarding primary and secondary prevention, research is primarily focused on identifying mechanisms to improve the safety-efficacy profile using a "hemostasis-sparing" approach. Further evaluation on those agents that have already shown promise for their risk/benefit profiles, would benefit greatly a neurologist's capacity to successfully prevent and treat ischemic stroke patients.

Silencing of circCDC14A prevents cerebral ischemia-reperfusion injury via miR-23a-3p/CXCL12 axis

Ischemic stroke is one of the main causes of death and disability. Circular RNAs (circRNAs) have received extensive attention in the pathogenesis of ischemic stroke. Here, we evaluated the role of circCDC14A in cerebral ischemia-reperfusion (CI/R) injury in vivo and in vitro. The expression of circCDC14A was significantly upregulated in the middle cerebral artery occlusion (MCAO) model and oxygen and glucose deprivation/reoxygenation (OGD/R)-treated HT22 cells. Knockdown of circCDC14A suppressed the cell viability reduction caused by OGD/R, as well as cell damage and apoptosis. Mechanistically, circCDC14A acted as a sponge for miR-23a-3p and promoted the expression of chemokine stromal-derived factor-1 (CXCL12) by negatively regulating miR-23a-3p. Rescue experiments further confirmed that miR-23a-3p inhibitor or circCDC14A-overexpression vectors blocked the beneficial effects of circCDC14A knockdown in OGD/R-induced HT22 cells. Moreover, knockdown of circCDC14A suppressed MCAO-induced cerebral infarction and neurological damage, as well as the brain tissue damage and neuronal apoptosis in vivo. Consistently, miR-23a-3p antagomir treatment abolished the cerebral protective effects of circCDC14A knockdown on MCAO mice. In conclusion, circCDC14A promoted CI/R injury by regulating the miR-23a-3p/CXCL12 axis, which suggested that circCDC14A may become a potential therapeutic target for CI/R injury.

MicroRNA miR-497 is closely associated with poor prognosis in patients with cerebral ischemic stroke

Cerebral ischemic stroke (CIS) is the most common type of stroke, which is highly hazardous. This investigation aims to analyze the correlation of miR-497 with CIS, so as to provide reliable evidence for clinical response to CIS and lay a solid foundation for follow-up research. Eighty-nine CIS patients and 39 concurrent physical examinees selected between June 2017 and October 2018 were enrolled as the research participants. Additionally, SD rats with increased miR-497 expression and normal SD rats were purchased for CIS modeling to observe the clinical implications of miR-497 in CIS, as well as the water content of brain tissue and neuronal apoptosis of rats. miR-497 expression was lower in CIS patients than in physical examinees, and that in patients with complete stroke (CS) was the lowest, which increased after treatment. As determined by the receiver operating characteristic curve (ROC) analysis, miR-497 had an outstanding diagnostic efficacy for CIS and was negatively correlated with the National Institutes of Health Stroke Scale (NIHSS) and MDA concentration, while positively related to SOD concentration. Prognostic follow-up demonstrated that decreased miR-497 expression in patients after treatment predicted an increased risk of prognostic death and recurrence. However, observed in rats, the water content of the brain tissue of rats with increased miR-497 expression was reduced, and the neuronal apoptosis rate of the brain tissue was inhibited. Taken together, with low expression in CIS, miR-497 is strongly related to CIS progression and is a candidate CIS marker.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Anti-Platelet Therapy in Mild Cerebral Infarction Patients on the Basis of CYP2C19 Metabolizer Status

This study aimed to investigate the effects of CYP2C19 metabolizer status on the clinical therapeutic efficacy of cerebral infarction. Patients with cerebral infarction (n = 180; NIHSS score ≤ 5) were recruited and divided into Group A and Group B according to CYP2C19 metabolizer status. In Group A, patients received routine clopidogrel therapy for 1 year; in Group B, the patients with extensive metabolizer (EM) were treated with clopidogrel, and patients with intermediate metabolizer (IM) and poor metabolizer (PM) were treated with aspirin for 1 year. On admission, National Institutes of Health Stroke Scale score was determined, and the therapeutic efficacy was evaluated with Modified Rankin Scale score after 1 year of treatment. The outcomes and adverse effects were recorded during the treatment. After routine clopidogrel treatment, the efficacy in EM patients was significantly better than in PM and IM patients. After adjustment of therapeutic protocol, the therapeutic efficacy in PM and IM patients was markedly improved, which was accompanied by significant reduction in recurrence rate of cerebral infarction. Although the adverse effects increased in patients receiving aspirin treatment, they resolved after symptomatic therapy. CYP2C19 metabolizer status is closely related to the clinical efficacy of clopidogrel. Thus, it is necessary to adjust the anti-platelet treatment according to the CYP2C19 metabolizer status to maximize therapeutic efficacy without increasing recurrence and adverse effects.

Stroke occurrence while on antiplatelet therapy may predict atrial fibrillation detected after stroke

BACKGROUND AND AIMS

Stroke occurrence while on antiplatelet therapy, i.e., a breakthrough stroke, is often conveniently attributed to antiplatelet resistance. However, undetected paroxysmal atrial fibrillation (AF) may underlie breakthrough strokes. We hypothesized that a breakthrough stroke may be a clinical marker for patients at risk of having AF detected after stroke (AFDAS).

METHODS

Consecutive patients without known AF hospitalized for ischemic stroke between 2000 and 2013 were identified from nationwide claims data. The independent variable of interest was continued use of antiplatelet therapy within 30 days before stroke. The diagnosis of AF and comorbidities were ascertained using validated algorithms. Stroke severity (National Institutes of Health Stroke Scale [NIHSS]) was estimated using a validated claims-based method. Univariable and multivariable Cox regression analyses were used to determine the effect of breakthrough strokes on the occurrence of AFDAS separately in patients with mild and severe stroke (estimated NIHSS ≤10 versus >10).

RESULTS

Among 17,076 patients (40% female, mean age 69 years), 3314 (19%) were on antiplatelet therapy before stroke. In patients with mild stroke, prior antiplatelet use was significantly associated with the occurrence of AFDAS (adjusted hazards ratio, 1.26; 95% confidence interval, 1.08-1.48). In contrast, no association existed between prior antiplatelet use and the risk of AFDAS in those with severe stroke.

CONCLUSIONS

Patients with a breakthrough stroke of mild severity while on antiplatelet therapy carried an increased risk of AFDAS compared to those not on antiplatelet therapy. Our findings may help prioritize patients for advanced cardiac monitoring in daily practice.

Carotid stenting with proximal cerebral protection in symptomatic low-grade vulnerable recurrent carotid stenosis

Background

Although the management of carotid disease is well established for symptomatic lesions ⩾70%, carotid revascularization for symptomatic low-grade (⩽50%) stenosis is not actually supported by data from randomized clinical trials. Such patients may occasionally have recurrent neurological symptoms despite optimal medical treatment owing to vulnerable plaques. In such cases, carotid artery stenting (CAS) may represent an option for treatment but this has not been tested in clinical trials. This study analyzed early and long-term outcomes of CAS performed in patients with low-grade symptomatic recurrent carotid stenosis.

Methods

From a prospective registry of 322 carotid revascularization in symptomatic patients, 21 consecutive patients with low-grade symptomatic recurrent carotid stenosis who underwent CAS with proximal cerebral protection device Mo.Ma, after ruling out any other source of cerebral embolization, were involved in the study.All patients had suggestive evidence of unstable plaque or plaque ulceration.

Results

Procedural technical success rate was 100%. No 30-day stroke or death occurred, and no patients had recurrent neurological events related to the revascularized hemisphere during follow up. No 30-day local complications were reported. No late carotid occlusions were detected. There was one late death, and no stroke-related deaths. Survival rates were 100% at 1 year and 96% at 3 years.

Conclusions

This study shows that CAS is a well-tolerated, effective and durable treatment for patients with recurrent symptomatic low-grade carotid stenosis associated with a vulnerable plaque. Patients had excellent protection against further ischemic events and survived long enough.