Multiple versus fewer antiplatelet agents for preventing early recurrence after ischaemic stroke or transient ischaemic attack

Determinants and Temporal Trends of Dual Antiplatelet Therapy After Mild Noncardioembolic Stroke

BACKGROUND

Short-term dual antiplatelet therapy (DAPT) reduces early stroke recurrence after mild noncardioembolic ischemic stroke (NCIS). We aim to evaluate temporal trends and determinants of DAPT prescription after mild NCIS in the Florida Stroke Registry, a statewide registry across Get With The Guidelines-Stroke participating hospitals.

METHODS

In this cross-sectional analysis of a cohort study, we included patients with mild NCIS (National Institutes of Health Stroke Scale score ≤3) who were potentially eligible for DAPT across 168 Florida Stroke Registry participating hospitals between January 2010 and September 2022. Using antiplatelet prescription as the dependent variable (DAPT versus single antiplatelet therapy), we fit logistic regression models adjusted for patient-related factors, hospital-related factors, clinical presentation, vascular risk factors, and ischemic stroke subtype, to obtain adjusted odds ratios (aORs) with 95% CIs.

RESULTS

From 283 264 Florida Stroke Registry ischemic stroke patients during the study period, 109 655 NCIS were considered eligible. Among these, 37 058 patients with National Institutes of Health Stroke Scale score >3 were excluded, resulting in a sample of 72 597 mild NCIS (mean age 68±14 years; female 47.3%). Overall, 24 693 (34.0%) patients with mild NCIS were discharged on DAPT and 47 904 (66.0%) on single antiplatelet therapy. DAPT prescription increased from 25.7% in 2010 to 52.8% in 2022 (β/year 2.5% [95% CI, 1.5%-3.4%]). Factors associated with DAPT prescription were premorbid antiplatelet therapy (aOR, 4.66 [95% CI, 2.20-9.88]), large-artery atherosclerosis (aOR, 1.68 [95% CI, 1.43-1.97]), diabetes (aOR, 1.29 [95% CI, 1.13-1.47]), and hyperlipidemia (aOR, 1.24 [95% CI, 1.10-1.39]), whereas female sex (aOR, 0.83 [95% CI, 0.75-0.93]), being non-Hispanic Black patients (compared with non-Hispanic White patients; aOR, 0.78 [95% CI, 0.68-0.90]), admission to a Thrombectomy-capable Stroke Center (compared with Comprehensive Stroke Center; aOR, 0.78 [95% CI, 0.66-0.92]), time-to-presentation 1 to 7 days from last seen well (compared with <24 h; aOR, 0.86 [95% CI, 0.76-0.96]), and small-vessel disease stroke (aOR, 0.81 [95% CI, 0.72-0.94]) were associated with not receiving DAPT at discharge.

CONCLUSIONS

Despite a temporal trend increase in DAPT prescription after mild NCIS, we found substantial underutilization of evidence-based DAPT associated with significant disparities in stroke care.

Single-Dose Pharmacokinetics of Milvexian in Participants with Normal Renal Function and Participants with Moderate or Severe Renal Impairment

OBJECTIVE

The aim of this study was to assess the effect of moderate or severe renal impairment on the pharmacokinetic (PK) properties of milvexian.

METHODS

This open-label, parallel-group study assessed the PK, safety, and tolerability of a single oral 60 mg dose of milvexian in participants with normal renal function (n = 8; estimated glomerular filtration rate [eGFR] ≥ 90 mL/min/1.73 m2) and participants with moderate (n = 8; eGFR ≥ 30 to ≤ 59 mL/min/1.73 m2) or severe (n = 8; eGFR < 30 mL/min/1.73 m2) renal impairment. Regression analysis was performed using linear regression of log-transformed PK parameters versus eGFR.

RESULTS

Milvexian was well tolerated, with no deaths, serious adverse events, or serious bleeding reported. The maximum milvexian concentration (Cmax) was similar for all groups. Based on a regression analysis of milvexian concentration versus eGFR, participants with eGFR values of 30 and 15 mL/min/1.73 m2, respectively, had area under the curve (AUC) values that were 41% and 54% greater than in participants with normal renal function. Median time to maximum concentration (Tmax) was similar for the three groups (4.5-5.0 h). The half-life increased for participants with moderate (18.0 h) or severe (17.7 h) renal impairment compared with those with normal renal function (13.8 h).

CONCLUSION

A single dose of milvexian 60 mg was safe and well tolerated in participants with normal renal function and moderate or severe renal impairment. There was a similar increase in milvexian exposure between the moderate and severe renal groups.

CLINICAL TRIALS REGISTRATION

This study was registered with ClinicalTrials.gov (NCT03196206, first posted 22 June 2017).

Dual Antiplatelet Therapy in the Management of Acute Minor Ischemic Stroke and High-Risk Transient Ischemic Attack: An Expert Consensus Statement From Taiwan Stroke Society and Taiwan Society of Emergency Medicine

The aim of this review is to achieve a consensus between Taiwan Stroke Society (TSS) and Taiwan Society of Emergency Medicine (TSEM) to manage acute non-cardioembolic minor ischemic stroke (MIS) and high-risk transient ischemic attack (TIA). The methodology is to review the recent findings from clinical trials of dual antiplatelet therapy (DAPT) from 2010 to 2021 and updates in clinical practice guidelines from 2018 to 2022 for non-cardioembolic MIS/TIA management at the acute stage. Four leading clinical studies, CHANCE, POINT, THALES, and CHANCE-2 along with other relevant studies introducing DAPT, are discussed in this review. The risk-benefit profile between stroke recurrence reduction and major bleeding increase is also elucidated. TSS and TSEM concluded that for patients presenting with non-cardioembolic MIS or high-risk TIA who did not receive intravenous alteplase, initiation of DAPT within 24 hours after stroke onset and continued up to 21 days, followed by antiplatelet monotherapy, is effective in reducing recurrent ischemic stroke for a period of up to 90 days.

Effects of Itraconazole and Diltiazem on the Pharmacokinetics and Pharmacodynamics of Milvexian, A Factor XIa Inhibitor

INTRODUCTION

Modulation of Factor XIa (FXIa) may provide a novel mechanism for systemic anticoagulation with the potential to improve the risk-benefit profile observed with existing anticoagulants through greater efficacy or a safer bleeding profile. This study assessed the effects of co-administration with strong and moderate CYP3A inhibitors itraconazole and diltiazem, respectively, on the pharmacokinetic and pharmacodynamic properties of milvexian, a Factor XIa inhibitor.

METHODS

This was an open-label, non-randomized, two-period crossover study in healthy participants. In period 1, participants received a single oral dose of milvexian (30 mg) on day 1, followed by a washout on days 2 and 3. In period 2, participants received multiple oral doses of itraconazole (200 mg) or diltiazem (240 mg) with a single dose of milvexian.

RESULTS

A total of 28 participants entered the treatment period. Following itraconazole co-administration, milvexian exposure was increased; AUC(0-T), AUC(INF), and C24 were 2.5-, 2.5-, and 3.8-fold higher, while mean Cmax was 28% higher versus milvexian alone. Diltiazem co-administration also increased milvexian exposure; AUC(0-T), AUC(INF), and C24 were 38, 38, and 64% higher, and mean Cmax was 9.6% higher versus milvexian alone. Prolongation of activated partial thromboplastin time was observed with milvexian in a concentration-dependent fashion irrespective of co-administration with itraconazole or diltiazem. Administration of a single dose of milvexian, alone or in combination with itraconazole or diltiazem, was generally safe and well tolerated; there were no deaths or serious adverse events.

CONCLUSIONS

A moderate increase in milvexian exposure was observed following co-administration of itraconazole while a minimal increase was seen with diltiazem, consistent with the involvement of CYP3A metabolism and P-glycoprotein in drug absorption/elimination. Milvexian was generally safe and well tolerated in healthy participants.

TRIAL REGISTRATION

The study was registered with ClinicalTrials.gov (NCT02807909; submitted June 17, 2016).

Analysis of Prescriptions for Dual Antiplatelet Therapy After Acute Ischemic Stroke

IMPORTANCE

After the publication of the CHANCE (Clopidogrel in High Risk Patients With Acute Nondisabling Cerebrovascular Events) and POINT (Platelet-Oriented Inhibition in New Transient Ischemic Attack and Minor Ischemic Stroke) clinical trials, the American Heart Association/American Stroke Association (AHA/ASA) issued a new class 1, level of evidence A, recommendation for dual antiplatelet therapy (DAPT; aspirin plus clopidogrel) for secondary prevention in patients with minor ischemic stroke (National Institutes of Health Stroke Scale [NIHSS] score ≤3). The extent to which variations in DAPT prescribing patterns remain and the extent to which practice patterns in the US are consistent with evidence-based guidelines are unknown.

OBJECTIVE

To evaluate the discharge DAPT prescribing patterns after publication of the new AHA/ASA guidelines and assess the extent of hospital-level variation in the use of DAPT for secondary prevention in patients with minor stroke (NIHSS score ≤3), as indicated by guidelines, and in patients with nonminor stroke (NIHSS score >3), for whom the risks and benefits of DAPT have not been fully established.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter retrospective cohort study involved 132 817 patients from 1890 hospitals participating in the AHA/ASA Get With The Guidelines-Stroke program. Patients who were hospitalized for acute ischemic stroke and prescribed antiplatelet therapy at discharge between October 1, 2019, and June 30, 2020, were included.

EXPOSURES

Minor ischemic stroke (NIHSS score ≤3) vs nonminor ischemic stroke (NIHSS score >3).

MAIN OUTCOMES AND MEASURES

The primary outcome was DAPT prescription at discharge. The extent to which variations in DAPT use were explained at the hospital level was assessed by calculating the median odds ratio (OR), which was derived using multivariable logistic regression analysis and compared the likelihood that 2 patients with identical clinical features admitted to 2 randomly selected hospitals (1 with higher propensity and 1 with lower propensity for DAPT use) would receive DAPT at discharge. Associations between hospital-level DAPT use among patients with minor vs nonminor stroke were evaluated using Pearson ρ correlation coefficients.

RESULTS

Among 132 817 patients (median [IQR] age, 68 [59-78] years; 68 768 men [51.8%]), 4282 (3.2%) were Asian, 11 254 (8.5%) were Hispanic, 27 221 (20.5%) were non-Hispanic Black, 84 468 (63.6%) were non-Hispanic White, and 5592 (4.2%) were of other races and/or ethnicities (including American Indian or Alaska Native, Native Hawaiian or Pacific Islander, and unable to determine). Overall, 86 551 patients (65.2%) presented with minor ischemic stroke, and 46 266 patients (34.8%) presented with nonminor ischemic stroke. After the 2019 AHA/ASA guideline updates, 40 661 patients (47.0%) with minor stroke (NIHSS median [IQR] score, 1 [0-2]) and 19 703 patients (42.6%) with nonminor stroke (NIHSS median [IQR] score, 6 [5-9]) received DAPT at discharge. Despite guideline recommendations, 45 890 patients (53.0%) with minor stroke did not receive DAPT. After accounting for patient characteristics, substantial hospital-level variations were found in the use of DAPT in those with minor stroke (median [IQR] hospital-level DAPT prescription rate, 44.8% [33.7%-57.7%]; range, 0%-91.7%; median OR, 2.03 [95% CI, 1.97-2.09]) when comparing 2 patients with identical risk factors discharged from 2 randomly selected hospitals, 1 with higher propensity and 1 with lower propensity for DAPT use. The use of DAPT in patients with nonminor stroke also varied significantly (median [IQR] hospital-level DAPT prescription rate, 41.4% [30.0%-53.8%]; range, 0%-100%; median OR, 1.90 [95% CI, 1.83-1.97]). Overall, hospitals that were more likely to prescribe DAPT for minor strokes were also more likely to prescribe DAPT for nonminor strokes (Pearson ρ = 0.72; P < .001).

CONCLUSIONS AND RELEVANCE

This cohort study found that despite updated AHA/ASA guidelines, more than 50% of patients with minor acute ischemic stroke did not receive DAPT at discharge. In contrast, more than 40% of patients with nonminor stroke received DAPT despite lack of evidence in this setting. These findings suggest that enhancing adherence to evidence-based DAPT practice guidelines may be a target for quality improvement in the treatment of patients with ischemic 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.

Antiplatelet Use in Ischemic Stroke

Objective:

A literature review of antiplatelet agents for primary and secondary stroke prevention, including mechanism of action, cost, and reasons for lack of benefit.

Data sources:

Articles were gathered from MEDLINE, Cochrane Reviews, and PubMed databases (1980-2021). Abstracts from scientific meetings were considered. Search terms included ischemic stroke, aspirin, clopidogrel, dipyridamole, ticagrelor, cilostazol, prasugrel, glycoprotein IIb/IIIa inhibitors.

Study selection and data extraction:

English-language original and review articles were evaluated. Guidelines from multiple countries were reviewed. Articles were evaluated independently by 2 authors.

Data synthesis:

An abundance of evidence supports aspirin and clopidogrel use for secondary stroke prevention. In the acute phase (first 21 days postinitial stroke), these medications have higher efficacy for preventing further stroke when combined, but long-term combination therapy is associated with higher hemorrhage rates. Antiplatelet treatment failure is influenced by poor adherence and genetic polymorphisms. Antiplatelet agents such as cilostazol may provide extra benefit over clopidogrel and aspirin, in certain racial groups, but further research in more diverse ethnic populations is needed.

Relevance to patient care and clinical practice:

This review presents the data available on the use of different antiplatelet agents poststroke. Dual therapy, recurrence after initiation of secondary preventative therapy, and areas for future research are discussed.

Conclusions:

Although good evidence exists for the use of certain antiplatelet agents postischemic stroke, there are considerable opportunities for future research to investigate personalized therapies. These include screening patients for platelet polymorphisms that confer antiplatelet resistance and for randomized trials including more racially diverse populations.

Oral antiplatelet therapy for acute ischaemic stroke

BACKGROUND

In people with acute ischaemic stroke, platelets become activated and can cause blood clots to form and block an artery in the brain, resulting in damage to part of the brain. Such damage gives rise to the symptoms of stroke. Antiplatelet therapy might reduce the volume of brain damaged by ischaemia and also reduce the risk of early recurrent ischaemic stroke, thereby reducing the risk of early death and improving long-term outcomes in survivors. However, antiplatelet therapy might also increase the risk of fatal or disabling intracranial haemorrhage.

OBJECTIVES

To assess the efficacy and safety of immediate oral antiplatelet therapy (i.e. started as soon as possible and no later than two weeks after stroke onset) in people with acute presumed ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, and two trials registers, and performed forward reference/cited reference searching in August 2020.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing oral antiplatelet therapy (started within 14 days of the stroke) with control in people with definite or presumed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria and assessed trial quality. For the included trials, they extracted and cross-checked the data. They assessed risk of bias of each study using the Risk of Bias 1 (RoB1) tool and overall certainty of the evidence for each outcome using the GRADE approach.

MAIN RESULTS

We included 11 studies involving 42,226 participants. Three new trials have been added since the last update (743 participants). As per the previous version of this review, two trials testing aspirin 160 mg to 300 mg once daily, started within 48 hours of onset, contributed 96% of the data. The risk of bias was low. The maximum follow-up was six months. With treatment, there was a decrease in death or dependency at the end of follow-up (odds ratio (OR) 0.95, 95% confidence interval (CI) 0.91 to 0.99; 7 RCTs, 42,034 participants; moderate-certainty evidence). For every 1000 people treated with aspirin, 13 people would avoid death or dependency (number needed to treat for an additional beneficial outcome 79).

AUTHORS' CONCLUSIONS

Antiplatelet therapy with aspirin 160 mg to 300 mg daily, given orally (or by nasogastric tube or per rectum in people who cannot swallow) and started within 48 hours of onset of presumed ischaemic stroke, significantly decreased death and dependency, and reduced the risk of early recurrent ischaemic stroke without a major risk of early haemorrhagic complications; long-term outcomes were improved.

Intrasaccular flow disruption (WEB) of a large wide-necked basilar apex aneurysm using PulseRider-assistance

Large, wide-necked basilar apex aneurysms are difficult to treat. Microsurgical clipping can result in neurologic morbidity and mortality. Endovascular treatment often leaves remnants that need retreatment and/or stent placement with dual antiplatelet therapy. The Woven EndoBridge (WEB) is an intrasaccular flow disruption device that can be used without dual antiplatelet therapy. However, the WEB cannot typically be used in large or giant aneurysms > 10 mm because the largest diameter device is the 11 × 9.6 mm single layer sphere (SLS). We present a case in which we use a PulseRider aneurysm neck reconstruction device in the basilar artery to assist in WEB deployment within a 22 mm basilar apex aneurysm with 14 mm neck, thereby permitting aspirin monotherapy postoperatively.