Risk for Major Bleeding in Patients Receiving Ticagrelor Compared With Aspirin After Transient Ischemic Attack or Acute Ischemic Stroke in the SOCRATES Study (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes)

An alternative reduced dose regimen of ticagrelor for neuroendovascular patients

OBJECTIVE

There is a growing use of ticagrelor in patients undergoing neuroendovascular procedures, especially those who demonstrate clopidogrel resistance. While multiple dosages are studied in the cardiology literature, the optimal dose for patients with neurological pathology has yet to be established. Here, we describe a single center experience involving 39 patients who underwent neuroendovascular procedures that then received an adjusted lower dose of ticagrelor.

METHODS

A retrospective chart review was performed between 2013 and 2017 for patients on dual anti-platelet therapy (DAPT) for either cervical or intracranial vascular pathologies, as well as stenting of the neurovasculature, including carotid arteries. Patients were placed on ticagrelor if their measured P2Y12 reaction units (PRU) responses to clopidogrel were outside the expected range in our center using the VerifyNow™ P2Y12 test. All patients were maintained on a dose of 45 mg twice daily except for one patient who received 22.5 mg twice daily. Responsiveness to ticagrelor were measured utilizing the VerifyNow™ P2Y12 test.

RESULTS

The mean number of days for follow-up post treatment initiation was 532 days. A total of 39 patients were included in the analysis. Of these, 8 patients (21%) received implantation of intracranial stents (5 patients received pipeline embolization devices, 1 patient received stent-assisted coiling, and 2 patients received intracranial stents for atherosclerotic disease). Fourteen patients (35%) received carotid angioplasty and stenting. Seventeen patients (44%) did not receive permanent implantation of a stent. All patients on the lower dose ticagrelor of 45 mg twice daily achieved responsiveness (i.e., PRU < 194). Hemorrhagic transformation of ischemic stroke occurred in one patient (2.5%). No other hemorrhagic complications were encountered. No thromboembolic events were recorded aside from one patient (2.5%) with intracranial atherosclerotic disease who had an ischemic event.

CONCLUSIONS

A lower dose of ticagrelor (45 mg twice daily) appears to be safe and effective in this small cohort of patients who are resistant to clopidogrel per P2Y12 testing and who have increased risk of ischemic or hemorrhagic strokes due to neurovascular pathologies and implants. Further randomized studies are required to confirm these findings.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Unruptured Intracranial Aneurysm Treated with Stent-Assisted Coil Embolization: A Single-Center Cohort Study

BACKGROUND

Dual antiplatelet therapy (DAPT) of aspirin plus clopidogrel is commonly used in patients with unruptured intracranial aneurysms treated with stent-assisted coil (SAC) embolization. However, the unpredictable clopidogrel efficacy of the 5%-55% nonresponders limits its use. Ticagrelor, as a potential alternative of clopidogrel, is an antiplatelet agent with low resistance rates but uncertain efficacy and safety in these patients.

METHODS

A single-center cohort study was performed to compare the efficacy and safety of ticagrelor with clopidogrel in the DAPT regimen in patients with unruptured intracranial aneurysms and treated with SAC. The patients with clopidogrel resistance identified as inadequate adenosine diphosphate inhibition rate determined by thromboelastography were treated with ticagrelor instead, and both drugs achieved adequate suppression of platelet aggregation when stents were implanted. The occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) and bleeding events was recorded through 6 months follow-up.

RESULTS

Data from 86 patients with 99 unruptured intracranial aneurysms and treated by SAC with clopidogrel were compared with those from 108 patients with 111 aneurysms and treated with ticagrelor. Neither the baseline characteristics nor the incidence of the MACCE or bleeding events differed between the groups. Ticagrelor exerted significantly higher adenosine diphosphate inhibition rate than that of the clopidogrel. Multivariable logistic regression analysis showed that the incidence of MACCE was related to hematocrit and fibrinogen levels.

CONCLUSIONS

Ticagrelor seemed to be as effective and safe as clopidogrel for SAC in unruptured intracranial aneurysms. Hematocrit and fibrinogen levels were independent risk factors for the incidence of MACCE.

Time Course for Benefit and Risk With Ticagrelor and Aspirin in Individuals With Acute Ischemic Stroke or Transient Ischemic Attack Who Carry CYP2C19 Loss-of-Function Alleles: A Secondary Analysis of the CHANCE-2 Randomized Clinical Trial

Importance

Dual antiplatelet therapy (DAPT) with ticagrelor and aspirin has been found to be effective for secondary prevention after minor ischemic stroke or transient ischemic attack (TIA) in individuals who carry CYP2C19 loss-of-function (LOF) alleles; however, uncertainties remain about the time course of benefit and risk with ticagrelor and aspirin in these patients.

Objective

To obtain time-course estimates of efficacy and risk with ticagrelor and aspirin after minor stroke or TIA in individuals with CYP2C19 LOF alleles.

Design, Setting, and Participants

The Ticagrelor or Clopidogrel With Aspirin in High-risk Patients With Acute Nondisabling Cerebrovascular Events II (CHANCE-2) randomized clinical trial enrolled patients 40 years and older from 202 hospitals in China with acute minor stroke or TIA who carried CYP2C19 LOF alleles between September 23, 2019, and March 22, 2021, and were followed up for 90 days. All 6412 patients enrolled in the CHANCE-2 trial were included in this secondary analysis. Data were analyzed in October 2021.

Interventions

Ticagrelor (180 mg on day 1 followed by 90 mg twice daily on days 2-90) or clopidogrel (300 mg on day 1 followed by 75 mg daily on days 2-90). All patients received aspirin (75-300 mg on day 1 followed by 75 mg daily for 21 days).

Main Outcomes and Measures

The efficacy outcome was major ischemic event, defined as the composite of ischemic stroke or nonhemorrhagic death. Safety outcomes included moderate to severe bleeding and any bleeding.

Results

A total of 6412 patients were included (3205 in the ticagrelor and aspirin group and 3207 in the clopidogrel and aspirin group). The median (IQR) age was 65 (57-71) years, and 4242 patients (66%) were men. The reduction of major ischemic events with ticagrelor and aspirin predominately occurred in the first week (absolute risk reduction, 1.34%; 95% CI, 0.29 to 2.39) and attenuated but remained in the next 3 weeks (absolute risk reduction in the second week, 0.11%; 95% CI, -0.24 to 0.45; absolute risk reduction in the third week, 0.14%; 95% CI, -0.11 to 0.38; absolute risk reduction in the fourth week, 0.04%; 95% CI, -0.18 to 0.25). The risk of moderate to severe bleeding was consistently low in the ticagrelor and aspirin group. The absolute increase in any bleeding seen in the first week (0.87%; 95% CI, 0.25 to 1.50) remained in the next 3 weeks (absolute increase in the second week, 1.21%; 95% CI, 0.75 to 1.68; absolute increase in the third week, 0.33%; 95% CI, -0.05 to 0.72; absolute increase in the fourth week, 0.23%; 95% CI, -0.03 to 0.49).

Conclusion and Relevance

Among patients with minor stroke or TIA who carried CYP2C19 LOF alleles, benefit with ticagrelor and aspirin was present predominately in the first week, with additional small benefit accruing in the next 2 weeks.

Long-term Risk of Bleeding and Ischemic Events After Ischemic Stroke or Transient Ischemic Attack in Young Adults

BACKGROUND AND OBJECTIVES

Guidelines recommend antithrombotic medication as secondary prevention for patients with ischemic stroke or TIA at young age based on results from trials in older patients. We investigated the long-term risk of bleeding and ischemic events in young patients after ischemic stroke or TIA.

METHODS

We included 30-day survivors of first-ever ischemic stroke or TIA aged 18-50 years from the FUTURE study, a prospective cohort study of stroke at young age. We obtained information on recurrent ischemia based on structured data collection from 1995 until 2014 as part of the FUTURE study follow-up, complemented with information on any bleeding and ischemic events by retrospective chart review from baseline until last medical consultation or June 2020. Primary outcome was any bleeding, secondary outcome any ischemic event during follow-up. Both were stratified for sex, age, etiology, and use of antithrombotic medication at discharge. Bleeding and ischemic events were classified according to location and bleeding events also by severity.

RESULTS

We included 544 patients (56.1% women, median age of 42.2; interquartile range [IQR] 36.5-46.7 years) with a median follow-up of 9.6 (IQR 2.5-14.3) years. Ten-year cumulative risk of any bleeding event was 21.8% (95% confidence interval [CI] 17.4-26.0) and 33.9% (95% CI 28.3-37.5) of any ischemic event. Risk of bleeding was higher in women with a cumulative risk of 28.2% (95% CI 21.6-34.3) versus 13.7% (95% CI 8.2-18.9) in men (p<0.01), mainly due to gynecological bleeds. Female sex (p<0.001) and age between 40 and 49 years old (p=0.04) were independent predictors of bleeding.

DISCUSSION

Young patients after ischemic stroke or TIA have a substantial long-term risk of both bleeding (especially women) and ischemic events. Future studies should investigate the effects of long-term antithrombotics in young patients, taking into account the risk of bleeding complications.

Time Course for Benefit and Risk of Ticagrelor and Aspirin in Acute Ischemic Stroke or Transient Ischemic Attack

OBJECTIVES

To investigate the short-term time course benefit and risk of ticagrelor with aspirin in acute mild-moderate ischemic stroke or high-risk transient ischemic attack (TIA) in the THALES (The Acute Stroke or Transient Ischemic Attack Treated with Ticagrelor and ASA for Prevention of Stroke and Death) trial.

METHODS

In an exploratory analysis of the THALES trial, we evaluated the cumulative incidence of irreversible efficacy and safety outcomes at different timepoints during the 30-day treatment period. The efficacy outcome was major ischemic events defined as a composite of ischemic stroke or non-hemorrhagic death. The safety outcome was major hemorrhage defined as a composite of intracranial hemorrhage and fatal bleedings. Net clinical impact was defined as the combination of these two endpoints.

RESULTS

This analysis included a total of 11,016 patients (5523 in the ticagrelor-aspirin group and 5493 in the aspirin group) with mean age of 65 years, and 39% were women. The reduction of major ischemic events by ticagrelor occurred in the first week (4.1% vs 5.3%; absolute risk reduction 1.15%, 95% CI 0.36% to 1.94%), and remained throughout the 30-day treatment period. An increase in major hemorrhage was seen during the first week and remained relatively constant in the following weeks (absolute risk increase, approximately 0.3%). Cumulative analysis showed that the net clinical impact favored ticagrelor-aspirin in the first week (absolute risk reduction 0.97%, 95% CI, 0.17% to 1.77%) and remained constant throughout the 30 days.

DISCUSSION

In patients with mild-moderate ischemic stroke or high-risk TIA, the treatment effect of ticagrelor-aspirin was present from the first week. The ischemic benefit of ticagrelor-aspirin outweighs the risk of major hemorrhage throughout the treatment period, which may support the use of 30 days treatment with ticagrelor and aspirin in these patients.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for patients with mild-moderate ischemic stroke or high-risk TIA, the ischemic benefit of ticagrelor-aspirin outweighs the risk of major hemorrhage throughout the 30-day treatment period.

Ischemic Benefit and Hemorrhage Risk of Ticagrelor-Aspirin Versus Aspirin in Patients With Acute Ischemic Stroke or Transient Ischemic Attack

Supplemental Digital Content is available in the text.

Background and Purpose:

In patients with acute mild-moderate ischemic stroke or high-risk transient ischemic attack, the THALES trial (Acute Stroke or Transient Ischemic Attack Treated With Ticagrelor and Aspirin for Prevention of Stroke and Death) demonstrated that when added to aspirin, ticagrelor reduced stroke or death but increased risk of severe hemorrhage compared with placebo. The primary efficacy outcome of THALES included hemorrhagic stroke and death, events also counted in the primary safety outcome. We sought to disentangle risk and benefit, assess their relative impact, and attempt to identify subgroups with disproportionate risk or benefit.

Methods:

In a randomized, placebo-controlled, double-blind trial of patients with mild-to-moderate acute noncardioembolic ischemic stroke or high-risk transient ischemic attack, patients were randomized within 24 hours after symptom onset to a 30-day regimen of either ticagrelor plus aspirin or matching placebo plus aspirin. For the present analyses, we defined the efficacy outcome, major ischemic events, as the composite of ischemic stroke or nonhemorrhagic death, and defined the safety outcome, major hemorrhage, as intracranial hemorrhage or hemorrhagic death. Net clinical impact was defined as the combination of these 2 end points.

Results:

In 11 016 patients (5523 ticagrelor-aspirin and 5493 aspirin), a major ischemic event occurred in 294 patients (5.3%) in the ticagrelor-aspirin group and in 359 patients (6.5%) in the aspirin group (absolute risk reduction 1.19% [95% CI, 0.31%–2.07%]). Major hemorrhage occurred in 22 patients (0.4%) in the ticagrelor-aspirin group and 6 patients (0.1%) in the aspirin group (absolute risk increase 0.29% [95% CI, 0.10%–0.48%]). Net clinical impact favored ticagrelor-aspirin (absolute risk reduction 0.97% [95% CI, 0.08%–1.87%]). Findings were similar when different thresholds for disability were applied and over a range of predefined subgroups.

Conclusions:

In patients with mild-moderate ischemic stroke or high-risk transient ischemic attack, ischemic benefits of 30-day treatment with ticagrelor-aspirin outweigh risks of hemorrhage.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03354429.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Intracranial Stenting or Flow-Diverter Treatment for Unruptured Cerebral Aneurysms: A Single-Center Cohort Study

BACKGROUND AND PURPOSE

Ticagrelor is a novel P2Y12 antagonist, and little is known about its efficacy and safety in the endovascular treatment of aneurysms. This study evaluated the efficacy and safety of ticagrelor versus clopidogrel for stent-assisted coiling or flow-diversion treatment in patients with unruptured cerebral aneurysms.

MATERIALS AND METHODS

From November 2003 to February 2019, two hundred one patients (mean age, 57.5 years; 156 women) with 233 unruptured aneurysms underwent stent-assisted coiling or flow-diversion treatment. All patients received antiplatelet therapy of aspirin plus clopidogrel (clopidogrel group, 121 patients with 140 aneurysms) or aspirin plus ticagrelor (ticagrelor group, 80 patients with 93 aneurysms). The clinical and radiologic data in each group were retrospectively reviewed and compared.

RESULTS

Two hundred thirty-six procedures were performed, including stent-assisted coiling (n = 101) and flow diversion (n = 135). At 90 days, the primary outcome-a composite of any stroke and death-occurred in 9.9% of the clopidogrel group and 8.6% of the ticagrelor group (P = .822). Ischemic stroke occurred in 10 (7.0%) of the clopidogrel group and 7 (7.5%) of the ticagrelor group (P > .999). Disabling stroke occurred in 4 (2.8%) in the clopidogrel group and in 4 (4.3%) in the ticagrelor group (P = .716). Ninety-day death occurred in 3 (2.1%) in the clopidogrel group and 1 (1.1%) in the ticagrelor group (P > .999). Any bleeding at 90 days occurred in 13 (9.2%) in the clopidogrel group and 6 (6.5%) in the ticagrelor group (P = .479).

CONCLUSIONS

Ticagrelor appears to be as effective and safe as clopidogrel in stent-assisted coiling or flow-diversion treatment for unruptured cerebral aneurysms.

Clopidogrel underactivity is a common in patients with acute symptomatic severe carotid stenosis

BACKGROUND

Clopidogrel is commonly used for secondary stroke prevention in patients with large vessel stenosis. Reduced Clopidogrel high on treatment platelet reactivity (CR) can lead to Clopidogrel underactivity (CU) causing acute thrombosis. However, the prevalence of CU among patients with acute symptomatic carotid disease remains unknown. Therefore, we aimed to find the prevalence and identify the predictors for CU among patients with acutely symptomatic carotid stenosis.

PATIENTS AND METHODS

Over the span of 14 months, CR was measured at the time of endovascular procedure in all patients undergoing angiography and stenting because of acute symptomatic carotid stenosis. Only patients treated per institutional protocol with a combination of Clopidogrel and Aspirin were included. CR was measured with VerifyNowP2Y12 reaction units (PRU) and CU was defined as PRU > 208. Patients with CU were compared to those without CU.

RESULTS

Thirty-five patients were included (mean age 71.3 ± 10, 76% men) and twelve (34.3%, mean age 71.8 ± 8.4, 58% men) had CU at the time of endovascular intervention. On univariate analysis more severe carotid stenosis was seen in CU patients (92.6 ± 6.5% vs 81.6 ± 13.6%, p = 0.013) and percent stenosis was independently associated with CU on multivariate analysis (p = 0.023).

CONCLUSIONS

CU is present in 1 of every 3 patients with acutely symptomatic carotid disease. The current results suggest that CR testing should become part of routine care in patients with acutely symptomatic carotid disease.

Ticagrelor Added to Aspirin in Acute Nonsevere Ischemic Stroke or Transient Ischemic Attack of Atherosclerotic Origin

BACKGROUND AND PURPOSE

Among patients with a transient ischemic attack or minor ischemic strokes, those with ipsilateral atherosclerotic stenosis of cervicocranial vasculature have the highest risk of recurrent vascular events.

METHODS

In the double-blind THALES (The Acute Stroke or Transient Ischemic Attack Treated With Ticagrelor and ASA for Prevention of Stroke and Death) trial, we randomized patients with a noncardioembolic, nonsevere ischemic stroke, or high-risk transient ischemic attack to ticagrelor (180 mg loading dose on day 1 followed by 90 mg twice daily for days 2-30) or placebo added to aspirin (300-325 mg on day 1 followed by 75-100 mg daily for days 2-30) within 24 hours of symptom onset. The present paper reports a prespecified analysis in patients with and without ipsilateral, potentially causal atherosclerotic stenosis ≥30% of cervicocranial vasculature. The primary end point was time to the occurrence of stroke or death within 30 days.

RESULTS

Of 11 016 randomized patients, 2351 (21.3%) patients had an ipsilateral atherosclerotic stenosis. After 30 days, a primary end point occurred in 92/1136 (8.1%) patients with ipsilateral stenosis randomized to ticagrelor and in 132/1215 (10.9%) randomized to placebo (hazard ratio 0.73 [95% CI, 0.56-0.96], P=0.023) resulting in a number needed to treat of 34 (95% CI, 19-171). In patients without ipsilateral stenosis, the corresponding event rate was 211/4387 (4.8%) and 230/4278 (5.4%), respectively (hazard ratio, 0.89 [95% CI, 0.74-1.08]; P=0.23, Pinteraction=0.245). Severe bleeding occurred in 4 (0.4%) and 3 (0.2%) patients with ipsilateral atherosclerotic stenosis on ticagrelor and on placebo, respectively (P=NS), and in 24 (0.5%) and 4 (0.1%), respectively, in 8665 patients without ipsilateral stenosis (hazard ratio=5.87 [95% CI, 2.04-16.9], P=0.001).

CONCLUSIONS

In this exploratory analysis comparing ticagrelor added to aspirin to aspirin alone, we found no treatment by ipsilateral atherosclerosis stenosis subgroup interaction but did identify a higher absolute risk and a greater absolute risk reduction of stroke or death at 30 days in patients with ipsilateral atherosclerosis stenosis than in those without. In this easily identified population, ticagrelor added to aspirin provided a clinically meaningful benefit with a number needed to treat of 34 (95% CI, 19-171). Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03354429.

Longitudinal Monitoring of Flow-Diverting Stent Tissue Coverage After Implant in a Bifurcation Model Using Neurovascular High-Frequency Optical Coherence Tomography

BACKGROUND

Tissue growth over covered branches is a leading cause of delayed thrombotic complications after flow-diverter stenting (FDS). Due to insufficient resolution, no imaging modality is clinically available to monitor this phenomenon.

OBJECTIVE

To evaluate high-frequency optical coherence tomography (HF-OCT), a novel intravascular imaging modality designed for the cerebrovascular anatomy with a resolution approaching 10 microns, to monitor tissue growth over FDS in an arterial bifurcation model.

METHODS

FDS were deployed in a rabbit model (n = 6), covering the aortic bifurcation. The animals were divided in different groups, receiving dual antiplatelet therapy (DAPT) (n = 4), aspirin only (n = 1), and no treatment (n = 1). HF-OCT data were obtained in vivo at 3 different time points in each animal. For each cross-sectional image, metal and tissue coverage of the jailed ostium was quantified. Scanning electron microscopy images of harvested arteries were subsequently obtained.

RESULTS

Good quality HF-OCT data sets were successfully acquired at implant and follow-up. A median value of 41 (range 21-55) cross-sectional images were analyzed per ostium for each time point. Between 0 and 30 d after implant, HF-OCT analysis showed a significantly higher ostium coverage when DAPT was not given. After 30 d, similar growth rates were found in the DAPT and in the aspirin group. At 60 d, a coverage of 90% was reached in all groups.

CONCLUSION

HF-OCT enables an accurate visualization of tissue growth over time on FDS struts. The use of FDS in bifurcation locations may induce a drastic reduction of the jailed-branch ostium area.

Ticagrelor Added to Aspirin in Acute Ischemic Stroke or Transient Ischemic Attack in Prevention of Disabling Stroke: A Randomized Clinical Trial

IMPORTANCE

Reduction of subsequent disabling stroke is the main goal of preventive treatment in the acute setting after transient ischemic attack (TIA) or minor ischemic stroke.

OBJECTIVE

To evaluate the superiority of ticagrelor added to aspirin in preventing disabling stroke and to understand the factors associated with recurrent disabling stroke.

DESIGN, SETTING, AND PARTICIPANTS

The Acute Stroke or Transient Ischemic Attack Treated With Ticagrelor and Aspirin for Prevention of Stroke and Death (THALES) was a randomized clinical trial conducted between January 22, 2018, and December 13, 2019, with a 30-day follow-up, at 414 hospitals in 28 countries. The trial included 11 016 patients with a noncardioembolic, nonsevere ischemic stroke or high-risk TIA, including 10 803 with modified Rankin Scale score (mRS) recorded at 30 days.

INTERVENTIONS

Ticagrelor (180-mg loading dose on day 1 followed by 90 mg twice daily for days 2-30) or placebo within 24 hours of symptom onset. All patients received aspirin, 300 to 325 mg on day 1 followed by 75 to 100 mg daily for days 2 to 30.

MAIN OUTCOMES AND MEASURES

Time to the occurrence of disabling stroke (progression of index event or new stroke) or death within 30 days, as measured by mRS at day 30. Disabling stroke was defined by mRS greater than 1.

RESULTS

Among participants with 30-day mRS greater than 1, mean age was 68.1 years, 1098 were female (42.6%), and 2670 had an ischemic stroke (95.8%) as a qualifying event. Among 11 016 patients, a primary end point with mRS greater than 1 at 30 days occurred in 221 of 5511 patients (4.0%) randomized to ticagrelor and in 260 of 5478 patients (4.7%) randomized to placebo (hazard ratio [HR], 0.83; 95% CI, 0.69-0.99, P = .04). A primary end point with mRS 0 or 1 at 30 days occurred in 70 of 5511 patients (1.3%) and 87 of 5478 patients (1.6%) (HR, 0.79; 95% CI, 0.57-1.08; P = .14). The ordinal analysis of mRS in patients with recurrent stroke showed a shift of the disability burden following a recurrent ischemic stroke in favor of ticagrelor (odds ratio, 0.77; 95% CI, 0.65-0.91; P = .002). Factors associated with disability were baseline National Institutes of Health Stroke Scale score 4 to 5, ipsilateral stenosis of at least 30%, Asian race/ethnicity, older age, and higher systolic blood pressure, while treatment with ticagrelor was associated with less disability.

CONCLUSIONS AND RELEVANCE

In patients with TIA and minor ischemic stroke, ticagrelor added to aspirin was superior to aspirin alone in preventing disabling stroke or death at 30 days and reduced the total burden of disability owing to ischemic stroke recurrence.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03354429.

Impact of Bleeding and Myocardial Infarction on Mortality in All-Comer Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND

Bleeding and myocardial infarction (MI) after percutaneous coronary intervention are independent risk factors for mortality. This study aimed to investigate the association of all-cause mortality after percutaneous coronary intervention with site-reported bleeding and MI, when considered as individual, repeated, or combined events.

METHODS

We used the data from the GLOBAL LEADERS trial (GLOBAL LEADERS: A Clinical Study Comparing Two Forms of Anti-Platelet Therapy After Stent Implantation), an all-comers trial of 15 968 patients undergoing percutaneous coronary intervention. Bleeding was defined as Bleeding Academic Research Consortium (BARC) 2, 3, or 5, whereas MI included periprocedural and spontaneous MIs according to the Third Universal Definition.

RESULTS

At 2-year follow-up, 1061 and 498 patients (6.64% and 3.12%) experienced bleeding and MI, respectively. Patients with a bleeding event had a 10.8% mortality (hazard ratio [HR], 5.97 [95% CI, 4.76-7.49]; P<0.001), and the mortality of patients with an MI was 10.4% (HR, 5.06 [95% CI, 3.72-6.90]; P<0.001), whereas the overall mortality was 2.99%. Albeit reduced over time, MI and even minor BARC 2 bleeding significantly influenced mortality beyond 1 year after adverse events (HR of MI, 2.32 [95% CI, 1.18-4.55]; P=0.014, and HR of BARC 2 bleeding, 1.79 [95% CI, 1.02-3.15]; P=0.044). The mortality rates in patients with repetitive bleeding, repetitive MI, and both bleeding and MI were 16.1%, 19.2%, and 19.0%, and their HRs for 2-year mortality were 8.58 (95% CI, 5.63-13.09; P<0.001), 5.57 (95% CI, 2.53-12.25; P<0.001), and 6.60 (95% CI, 3.44-12.65; P<0.001), respectively. De-escalation of antiplatelet therapy at the time of BARC 3 bleeding was associated with a lower subsequent bleeding or MI rate, compared with continuation of antiplatelet therapy (HR, 0.32 [95% CI, 0.11-0.92]; P=0.034).

CONCLUSIONS

The fatal impact of bleeding and MI persisted beyond one year. Additional bleeding or MIs resulted in a poorer prognosis. De-escalation of antiplatelet therapy at the time of BARC 3 bleeding could have a major safety merit. These results emphasize the importance of considering the net clinical benefit including ischemic and bleeding events. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01813435.

Ticagrelor and Aspirin or Aspirin Alone in Acute Ischemic Stroke or TIA

BACKGROUND

Trials have evaluated the use of clopidogrel and aspirin to prevent stroke after an ischemic stroke or transient ischemic attack (TIA). In a previous trial, ticagrelor was not better than aspirin in preventing vascular events or death after stroke or TIA. The effect of the combination of ticagrelor and aspirin on prevention of stroke has not been well studied.

METHODS

We conducted a randomized, placebo-controlled, double-blind trial involving patients who had had a mild-to-moderate acute noncardioembolic ischemic stroke, with a National Institutes of Health Stroke Scale (NIHSS) score of 5 or less (range, 0 to 42, with higher scores indicating more severe stroke), or TIA and who were not undergoing thrombolysis or thrombectomy. The patients were assigned within 24 hours after symptom onset, in a 1:1 ratio, to receive a 30-day regimen of either ticagrelor (180-mg loading dose followed by 90 mg twice daily) plus aspirin (300 to 325 mg on the first day followed by 75 to 100 mg daily) or matching placebo plus aspirin. The primary outcome was a composite of stroke or death within 30 days. Secondary outcomes were first subsequent ischemic stroke and the incidence of disability within 30 days. The primary safety outcome was severe bleeding.

RESULTS

A total of 11,016 patients underwent randomization (5523 in the ticagrelor-aspirin group and 5493 in the aspirin group). A primary-outcome event occurred in 303 patients (5.5%) in the ticagrelor-aspirin group and in 362 patients (6.6%) in the aspirin group (hazard ratio, 0.83; 95% confidence interval [CI], 0.71 to 0.96; P = 0.02). Ischemic stroke occurred in 276 patients (5.0%) in the ticagrelor-aspirin group and in 345 patients (6.3%) in the aspirin group (hazard ratio, 0.79; 95% CI, 0.68 to 0.93; P = 0.004). The incidence of disability did not differ significantly between the two groups. Severe bleeding occurred in 28 patients (0.5%) in the ticagrelor-aspirin group and in 7 patients (0.1%) in the aspirin group (P = 0.001).

CONCLUSIONS

Among patients with a mild-to-moderate acute noncardioembolic ischemic stroke (NIHSS score ≤5) or TIA who were not undergoing intravenous or endovascular thrombolysis, the risk of the composite of stroke or death within 30 days was lower with ticagrelor-aspirin than with aspirin alone, but the incidence of disability did not differ significantly between the two groups. Severe bleeding was more frequent with ticagrelor. (Funded by AstraZeneca; THALES ClinicalTrial.gov number, NCT03354429.).

Methodologies for pragmatic and efficient assessment of benefits and harms: Application to the SOCRATES trial

BACKGROUND/AIMS

Standard approaches to trial design and analyses can be inefficient and non-pragmatic. Failure to consider a range of outcomes impedes evidence-based interpretation and reduces power. Traditional approaches synthesizing information obtained from separate analysis of each outcome fail to incorporate associations between outcomes and recognize the cumulative nature of outcomes in individual patients, suffer from competing risk complexities during interpretation, and since efficacy and safety analyses are often conducted on different populations, generalizability is unclear. Pragmatic and efficient approaches to trial design and analyses are needed.

METHODS

Approaches providing a pragmatic assessment of benefits and harms of interventions, summarizing outcomes experienced by patients, and providing sample size efficiencies are described. Ordinal outcomes recognize finer gradations of patient responses. Desirability of outcome ranking is an ordinal outcome combining benefits and harms within patients. Analysis of desirability of outcome ranking can be based on rank-based methodologies including the desirability of outcome ranking probability, the win ratio, and the proportion in favor of treatment. Partial credit analyses, involving grading the levels of the desirability of outcome ranking outcome similar to an academic test, provides an alternative approach. The methodologies are demonstrated using the acute stroke or transient ischemic attack treated with aspirin or ticagrelor and patient outcomes study (SOCRATES; NCT01994720), a randomized clinical trial.

RESULTS

Two 5-level ordinal outcomes were developed for SOCRATES. The first was based on a modified Rankin scale. The odds ratio is 0.86 (95% confidence interval = 0.75, 0.99; p = 0.04) indicating that the odds of worse stroke categorization for a trial participant assigned to ticagrelor is 0.86 times that of a trial participant assigned to aspirin. The 5-level desirability of outcome ranking outcome incorporated and prioritized survival; the number of strokes, myocardial infarction, and major bleeding events; and whether a stroke event was disabling. The desirability of outcome ranking probability and win ratio are 0.504 (95% confidence interval = 0.499, 0.508; p = 0.10) and 1.11 (95% confidence interval = 0.98, 1.26; p = 0.10), respectively, implying that the probability of a more desirable result with ticagrelor is 50.4% and that a more desirable result occurs 1.11 times more frequently on ticagrelor versus aspirin.

CONCLUSION

Ordinal outcomes can improve efficiency through required pre-specification, careful construction, and analyses. Greater pragmatism can be obtained by composing outcomes within patients. Desirability of outcome ranking provides a global assessment of the benefits and harms that more closely reflect the experience of patients. The desirability of outcome ranking probability, the proportion in favor of treatment, the win ratio, and partial credit can more optimally inform patient treatment, enhance the understanding of the totality of intervention effects on patients, and potentially provide efficiencies over standard analyses. The methods provide the infrastructure for incorporating patient values and estimating personalized effects.

Risk for Major Hemorrhages in Patients Receiving Clopidogrel and Aspirin Compared With Aspirin Alone After Transient Ischemic Attack or Minor Ischemic Stroke: A Secondary Analysis of the POINT Randomized Clinical Trial

Importance

Results show the short-term risk of hemorrhage in treating patients with acute transient ischemic attack (TIA) or minor acute ischemic stroke (AIS) with clopidogrel plus aspirin or aspirin alone.

Objective

To characterize the frequency and kinds of major hemorrhages in the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial.

Design, Setting, and Participants

This secondary analysis of the POINT randomized, double-blind clinical trial conducted in 10 countries in North America, Europe, and Australasia included patients with high-risk TIA or minor AIS who were randomized within 12 hours of symptom onset and followed up for 90 days. The total enrollment, which occurred from May 28, 2010, through December 17, 2017, was 4881 and constituted the intention-to-treat group; 4819 (98.7%) were included in the as-treated analysis group. The primary safety analyses were as-treated, classifying patients based on study drug actually received. Intention-to-treat analyses were performed as secondary analyses. Data were analyzed in April 2018.

Interventions

Patients were assigned to receive clopidogrel (600 mg loading dose on day 1 followed by 75 mg daily for days 2-90) or placebo; all patients also received open-label aspirin, 50 to 325 mg/d.

Main Outcomes and Measures

The primary safety outcome was all major hemorrhages. Other safety outcomes included minor hemorrhages.

Results

A total of 269 sites worldwide randomized 4881 patients (median age, 65.0 years [interquartile range, 55-74 years]; 2195 women [45.0%]); the primary results have been published previously. In the as-treated analyses, major hemorrhage occurred in 21 patients (0.9%) receiving clopidogrel plus aspirin and 6 (0.2%) in the aspirin alone group (hazard ratio, 3.57; 95% CI, 1.44-8.85; P = .003; number needed to harm, 159). There were 4 fatal hemorrhages (0.1%; 3 in the clopidogrel plus aspirin group and 1 in the aspirin alone group); 3 of the 4 were intracranial. There were 7 intracranial hemorrhages (0.1%); 5 were in the clopidogrel plus aspirin group and 2 in the aspirin plus placebo group. The most common location of major hemorrhages was in the gastrointestinal tract.

Conclusions and Relevance

The risk for major hemorrhages in patients receiving either clopidogrel plus aspirin or aspirin alone after TIA or minor AIS was low. Nevertheless, treatment with clopidogrel plus aspirin increased the risk of major hemorrhages over aspirin alone from 0.2% to 0.9%.

Trial Registration

ClinicalTrials.gov identifier: NCT00991029.

Estimated treatment effect of ticagrelor versus aspirin by investigator-assessed events compared with judgement by an independent event adjudication committee in the SOCRATES trial

BACKGROUND

Adjudication of endpoints is a standard procedure in cardiovascular clinical trials. However, several studies indicate that the benefit of adjudication in estimating treatment effect may be limited.

AIMS

This post hoc analysis of SOCRATES (NCT01994720) compared the treatment effects and investigated the agreement of clinical event assessment by site investigators and independent adjudicators.

METHODS

SOCRATES compared ticagrelor and aspirin in 13,199 patients with acute minor stroke or high-risk transient ischemic attack. The primary endpoint was stroke, myocardial infarction, or death. Stroke was the major component of the primary endpoint and a secondary endpoint. The endpoints were adjudicated by a blinded independent committee. We compared the treatment effect on the primary endpoint and stroke alone based on the investigators' and adjudicators' assessments, and investigated the agreement rate on the stroke endpoint and major hemorrhages.

RESULTS

The hazard ratios (95% confidence interval) for ticagrelor versus aspirin therapy for the primary endpoint were 0.89 (0.78-1.01) when calculated on adjudicator-assessed events and 0.88 (0.78-1.00) for investigator-assessed events. The hazard ratios (95% confidence intervals) for stroke were 0.86 (0.75-0.99) based on the adjudicators' diagnoses and 0.85 (0.75-0.97) based on the investigators' diagnoses. The overall agreement between adjudicator- and investigator-diagnosed stroke was 91%, and for major hemorrhages was 88%.

CONCLUSIONS

In SOCRATES, there was no clinically meaningful difference in the estimated treatment effect, on either the primary endpoint or stroke, by using investigator- or adjudicator-assessed events. Double-blind treatment outcome studies with stroke endpoints may not benefit from adjudication.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01994720.

Time to Loading Dose and Risk of Recurrent Events in the SOCRATES Trial

Background and Purpose- Recurrent ischemia risk is high in the acute period after cerebral ischemic events. Effects of antiplatelet agents may vary by time to loading dose (TLD). We explored the risk of recurrent events and safety and efficacy of ticagrelor versus aspirin in relation to TLD. Methods- We randomized 13 199 patients with noncardioembolic, nonsevere ischemic stroke, or high-risk transient ischemic attack to 90-day ticagrelor or aspirin treatment within 24 hours of symptom onset. For this analysis, 13 126 patients were categorized by TLD as <12 hours or ≥12 hours from start of index event. The primary end point was the composite of stroke, myocardial infarction, or death within 90 days. Major bleeding was the primary safety end point. Results- TLD was <12 hours in 4403 (33.5%) and ≥12 hours in 8723 (66.5%). The Kaplan-Meier% for the primary end point for all patients with TLD<12 hours was 7.5% versus 6.9% in TLD≥12 hours. Among patients with TLD<12 hours, the primary end point occurred in 147/2196 (6.8%) randomized to ticagrelor and in 184/2207 (8.3%) randomized to aspirin (hazard ratio, 0.79; 95% CI, 0.64-0.98; P=0.036). Among patients with TLD≥12 hours, the primary end point occurred in 6.7% patients randomized to ticagrelor versus 7.0% to aspirin (hazard ratio, 0.95; 95% CI, 0.81-1.12; P=0.55). There was no significant treatment-by-TLD interaction. Major bleeding rates were comparable on ticagrelor and aspirin, regardless of TLD. Conclusions- The event rate for the primary end point was higher in patients treated early (<12 hours) versus later (≥12 hours). In this exploratory analysis, a larger numerical difference in the primary end point was observed among patients on ticagrelor than on aspirin when TLD was <12 hours compared with ≥12 hours, although the interaction terms for treatment-by-TLD were not significant. For major bleeding, no relation to TLD was observed. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT01994720.

The Acute Stroke or Transient Ischemic Attack Treated with Ticagrelor and Aspirin for Prevention of Stroke and Death (THALES) trial: Rationale and design

Rationale

In patients with acute cerebral ischemia, the rate of stroke, myocardial infarction, or death during 90 days was reported to be non-significantly lower with ticagrelor compared with aspirin, with no increase in major hemorrhage. Dual antiplatelet therapy may be more effective in this setting.

Aim

To investigate whether ticagrelor combined with aspirin are superior to aspirin alone in preventing stroke or death in patients with non-severe, non-cardioembolic ischemic stroke or high-risk transient ischemic attack.

Design

The Acute Stroke or Transient Ischemic Attack Treated with Ticagrelor and Aspirin for Prevention of Stroke and Death (THALES) trial is a randomized, placebo-controlled, double-blind, event-driven study. Patients will be randomized within 24 h of onset of acute ischemic symptoms. THALES is expected to randomize 13,000 at ∼450 sites worldwide, to collect 764 primary outcome events. Study treatments are ticagrelor 180 mg loading dose on day 1, then 90 mg twice daily on days 2–30, or matching placebo. All patients will also receive open-label aspirin 300–325 mg on day 1, then 75–100 mg once daily on days 2–30.

Study outcomes

The primary efficacy outcome is time to the composite endpoint of stroke or death through 30-day follow-up. The primary safety outcome is time to first severe bleeding event.

Discussion

The THALES trial will provide important information about the benefits and risks of dual antiplatelet therapy with ticagrelor and aspirin in patients with acute cerebral ischemia in a global setting (funding: AstraZeneca).

Clinical Trial Registration URL

http://www.clinicaltrials.gov. Unique identifier: NCT03354429.

Efficacy and Safety of Ticagrelor in Relation to Aspirin Use Within the Week Before Randomization in the SOCRATES Trial

BACKGROUND AND PURPOSE

SOCRATES (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes), comparing ticagrelor with aspirin in patients with acute cerebral ischemia, found a nonsignificant 11% relative risk reduction for stroke, myocardial infarction, or death (P=0.07). Aspirin intake before randomization could enhance the effect of ticagrelor by conferring dual antiplatelet effect during a high-risk period for subsequent stroke. Therefore, we explored the efficacy and safety of ticagrelor versus aspirin in the patients who received any aspirin the week before randomization.

METHODS

A prespecified subgroup analysis in SOCRATES (n=13 199), randomizing patients with acute ischemic stroke (National Institutes of Health Stroke Scale score of ≤5) or transient ischemic attack (ABCD² score of ≥4) to 90-day treatment with ticagrelor or aspirin. Patients in the prior-aspirin group had received any aspirin within the week before randomization. Primary end point was time to stroke, myocardial infarction, or death. Safety end point was PLATO (Study of Platelet Inhibition and Patient Outcomes) major bleeding.

RESULTS

The 4232 patients in the prior-aspirin group were older, had more vascular risk factors, and vascular disease than the other patients. In the prior-aspirin group, the primary end point occurred in 138/2130 (6.5%) of patients on ticagrelor and in 177/2102 (8.3%) on aspirin (hazard ratio, 0.76; 95% confidence interval, 0.61-0.95; P=0.02); in patients with no prior-aspirin usage an event occurred in 304/4459 (6.9%) and 320/4508 (7.1%) on ticagrelor and aspirin, respectively (hazard ratio, 0.96; 95% confidence interval, 0.82-1.12; P=0.59). The treatment-by-prior-aspirin interaction was not statistically significant (P=0.10). In the prior-aspirin group, major bleeding occurred in 0.7% and 0.4% of patients on ticagrelor and aspirin, respectively (hazard ratio, 1.58; 95% confidence interval, 0.68-3.65; P=0.28).

CONCLUSIONS

In this secondary analysis from SOCRATES, fewer primary end points occurred on ticagrelor treatment than on aspirin in patients receiving aspirin before randomization, but there was no significant treatment-by-prior-aspirin interaction. A new study will investigate the benefit-risk of combining ticagrelor and aspirin in patients with acute cerebral ischemia (URL: https://www.clinicaltrials.gov. Unique identifier: NCT03354429).

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01994720.

Recent advances in the management of transient ischemic attacks

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5-10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients.