Dataset Information

Evaluation of Systolic Blood Pressure, Use of Aspirin and Clopidogrel, and Stroke Recurrence in the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke Trial.

ABSTRACT:

Importance

Elevated systolic blood pressure (SBP) after acute ischemic stroke and transient ischemic attack (TIA) is associated with future stroke risk.

Objective

To explore the association of dual antiplatelet therapy (DAPT) with stroke recurrence among patients with acute ischemic stroke and TIA with or without elevated baseline SBP.

Design, setting, and participants

This cohort study performed a post hoc subgroup analysis of the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial, which was a multicenter trial conducted from 2010 to 2018 at 269 sites in 10 countries in North America, Europe, Australia, and New Zealand. Patients enrolled in POINT with available blood pressure and outcome data were included in this cohort. Statistical analysis was performed from November 2020 to January 2021.

Exposures

Baseline SBP less than 140 mm Hg vs greater than or equal to 140 mm Hg and the interaction term of SBP (<140 mm Hg vs ≥140 mm Hg) × treatment group (aspirin vs DAPT).

Main outcomes and measures

The primary outcome was ischemic stroke during 90 days of follow-up. The statistical analysis fit Cox proportional hazards models adjusted for patient age, race, premorbid hypertension, diabetes, and final diagnosis of the qualifying event (stroke vs TIA).

Results

Among 4781 patients in the cohort, the mean (SD) age was 64.6 (13.1) years; 2142 (44.8%) were male individuals, 3487 (72.9%) were White individuals, and 266 (5.6%) had a primary outcome of ischemic stroke during follow-up. There were 946 patients (19.8%) with baseline SBP less than 140 mm Hg and 3835 (80.2%) with SBP greater than or equal to 140 mm Hg. The interaction term (SBP × treatment) was significant (P for interaction = .03). In the subgroup of patients with SBP less than 140 mm Hg, the hazard ratio (HR) of DAPT vs aspirin alone for ischemic stroke was 0.36 (95% CI, 0.18-0.72; P = .004), whereas the HR in the subgroup with SBP greater than or equal to 140 mm Hg was 0.79 (95% CI, 0.60-1.02; P = .08). When evaluating the outcome of ischemic stroke within 7 days of randomization, the interaction term was significant (P for interaction = .02), and the HR for patients with DAPT with SBP less than 140 mm Hg was 0.19 (95% CI, 0.07-0.55; P = .002).

Conclusions and relevance

In the POINT trial, patients with SBP less than 140 mm Hg at presentation received a greater benefit from 90 days of DAPT than those with higher baseline SBP, particularly for reduction of early ischemic stroke recurrence. Additional research is needed to replicate these findings and potentially test whether mild SBP reduction and DAPT within 12 hours of stroke onset lowers early risk of stroke recurrence.

SUBMITTER: de Havenon A

PROVIDER: S-EPMC8178708 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ImportanceDual antiplatelet therapy with clopidogrel and aspirin is effective for secondary prevention after minor ischemic stroke or transient ischemic attack (TIA). Uncertainties remained about the optimal duration of dual antiplatelet therapy for minor stroke or TIA.ObjectiveTo obtain precise estimates of efficacy and risk of dual antiplatelet therapy after minor ischemic stroke or TIA.Design, setting, and participantsThis analysis pooled individual patient-level data from 2 large-scale randomized clinical trials that evaluated clopidogrel-aspirin as a treatment to prevent stroke after a minor stroke or high-risk TIA. The Clopidogrel in High-Risk Patients With Acute Non-Disabling Cerebrovascular Events (CHANCE) trial enrolled patients at 114 sites in China from October 1, 2009, to July 30, 2012. The Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial enrolled patients at 269 international sites from May 28, 2010, to December 19, 2017. Both were followed up for 90 days. Data analysis occurred from November 2018 to May 2019.InterventionsIn the 2 trials, patients with minor stroke or high-risk TIA were randomized to clopidogrel-aspirin or aspirin alone within 12 hours (POINT) or 24 hours (CHANCE) of symptom onset.Main outcomes and measuresThe primary efficacy outcome was a major ischemic event (ischemic stroke, myocardial infarction, or death from ischemic vascular causes). The primary safety outcome was major hemorrhage.ResultsThe study enrolled 5170 patients (CHANCE) and 4881 patients (POINT). Analysis included individual data from 10 051 patients (5016 in the clopidogrel-aspirin treatment group and 5035 in the control group) with a median age of 63.2 (interquartile range, 55.0-72.9) years; 6106 patients (60.8%) were male. Clopidogrel-aspirin treatment reduced the risk of major ischemic events at 90 days compared with aspirin alone (328 of 5016 [6.5%] vs 458 of 5035 [9.1%]; hazard ratio [HR], 0.70 [95% CI, 0.61-0.81]; P < .001), mainly within the first 21 days (263 of 5016 [5.2%] vs 391 of 5035 [7.8%]; HR, 0.66 [95% CI, 0.56-0.77]; P < .001), but not from day 22 to day 90. No evidence of heterogeneity of treatment outcome across trials or prespecified subgroups was observed. Major hemorrhages were more frequent in the clopidogrel-aspirin group, but the difference was nonsignificant.Conclusions and relevanceIn this analysis of the POINT and CHANCE trials, the benefit of dual antiplatelet therapy appeared to be confined to the first 21 days after minor ischemic stroke or high-risk TIA.

Project description:BACKGROUND:Combination antiplatelet therapy with clopidogrel and aspirin may reduce the rate of recurrent stroke during the first 3 months after a minor ischemic stroke or transient ischemic attack (TIA). A trial of combination antiplatelet therapy in a Chinese population has shown a reduction in the risk of recurrent stroke. We tested this combination in an international population. METHODS:In a randomized trial, we assigned patients with minor ischemic stroke or high-risk TIA to receive either clopidogrel at a loading dose of 600 mg on day 1, followed by 75 mg per day, plus aspirin (at a dose of 50 to 325 mg per day) or the same range of doses of aspirin alone. The dose of aspirin in each group was selected by the site investigator. The primary efficacy outcome in a time-to-event analysis was the risk of a composite of major ischemic events, which was defined as ischemic stroke, myocardial infarction, or death from an ischemic vascular event, at 90 days. RESULTS:A total of 4881 patients were enrolled at 269 international sites. The trial was halted after 84% of the anticipated number of patients had been enrolled because the data and safety monitoring board had determined that the combination of clopidogrel and aspirin was associated with both a lower risk of major ischemic events and a higher risk of major hemorrhage than aspirin alone at 90 days. Major ischemic events occurred in 121 of 2432 patients (5.0%) receiving clopidogrel plus aspirin and in 160 of 2449 patients (6.5%) receiving aspirin plus placebo (hazard ratio, 0.75; 95% confidence interval [CI], 0.59 to 0.95; P=0.02), with most events occurring during the first week after the initial event. Major hemorrhage occurred in 23 patients (0.9%) receiving clopidogrel plus aspirin and in 10 patients (0.4%) receiving aspirin plus placebo (hazard ratio, 2.32; 95% CI, 1.10 to 4.87; P=0.02). CONCLUSIONS:In patients with minor ischemic stroke or high-risk TIA, those who received a combination of clopidogrel and aspirin had a lower risk of major ischemic events but a higher risk of major hemorrhage at 90 days than those who received aspirin alone. (Funded by the National Institute of Neurological Disorders and Stroke; POINT ClinicalTrials.gov number, NCT00991029 .).

Project description:Background: The combination of clopidogrel and aspirin is recommended for the treatment of patients with acute minor stroke or transient ischemic attack (TIA). However, with varied clopidogrel resistance (often due to CYP2C19 loss-of-function (LOF) alleles), alternatives like ticagrelor have been suggested. Previous studies showed that ticagrelor had a lower platelet reactivity assessed by VerifyNow P2Y12 assay than clopidogrel. We aimed to compare the effect of ticagrelor vs. clopidogrel on platelet reactivity assessed by a different method (Aggrestar platelet function analyzer) and analyze whether CYP2C19 genotypes were involved. Methods: A pre-specified subgroup analysis of a randomized controlled trial- Platelet Reactivity in Acute Non-disabling Cerebrovascular Events (PRINCE) was conducted. Patients with minor stroke or TIA were randomized for treatment with ticagrelor plus aspirin or clopidogrel plus aspirin. Platelet reactivity was assessed by Aggrestar (PL) platelet function analyzer and high on-treatment platelet reactivity (HOPR) on ticagrelor or clopidogrel was compared. Clinical outcomes included any stroke, composite vascular events and bleeding events within 90 days. Patients were categorized into carriers and non-carriers according to the carrier status of CYP2C19 LOF alleles. Results: Among 675 patients enrolled in the PRINCE trial, 387 patients were included in this subgroup: 197 were randomized to ticagrelor plus aspirin and 190 to clopidogrel plus aspirin. At 90 ± 7 days, compared with clopidogrel/aspirin group, the proportion of HOPR in ticagrelor/aspirin group was significantly lower (19.6 vs. 40.8%, P < 0.001). No significant treatment-by-genotype interactions were found (P for interaction = 0.12). Within 90 days, a trend toward a lower risk of new stroke in ticagrelor/aspirin compared to clopidogrel/aspirin was observed (4.6 vs. 9.5%, HR 0.47, 95% CI 0.21-1.05, P = 0.06). Conclusions: Ticagrelor is superior to clopidogrel in inhibiting platelet reactivity measured by the PL platelet function analyzer among patients with acute minor stroke or TIA. Our study confirmed the finding of the main analysis of PRINCE trial in a different assay. Large randomized controlled trials are needed to evaluate our findings. Clinical Trial Registration: Clinicaltrials.gov NCT02506140.

Project description:Background and objectiveGenotype data of the Clopidogrel with Aspirin in Acute Minor Stroke or Transient Ischemic Attack (CHANCE) trial showed that efficacy of clopidogrel aspirin depended on CYP2C19 genotype and risk profile. A stratification of patients who carried CYP2C19 loss-of-function (LOF) alleles according to the risk of recurrent stroke may be important for selecting optimal antiplatelet therapy. We aimed to compare the efficacy and safety of ticagrelor aspirin with clopidogrel aspirin in CYP2C19 LOF carriers with minor stroke or transient ischemic attack (TIA) stratified by risk profile.MethodsData were obtained from Ticagrelor or Clopidogrel with Aspirin in High-Risk Patients with Acute Nondisabling Cerebrovascular Events II (CHANCE-2) trial. Low-risk and high-risk profiles were defined by Essen Stroke Risk Score (ESRS) (<3 [low risk] and ≥3 [high risk], respectively).ResultsA total of 6,412 CYP2C19 LOF carriers were enrolled; ticagrelor aspirin was associated with a reduced risk of primary outcome (new stroke within 90-day follow-up) in patients at low risk (hazard ratio [HR], 0.65; 95% CI, 0.48-0.82), but not in those at high risk (HR, 0.97; 95% CI, 0.73-1.29), compared with clopidogrel aspirin (p = 0.02 for interaction). Secondary outcomes generally went in the same direction as the primary outcome. The primary safety outcome of severe or moderate bleeding did not differ based on risk profile (p = 0.24 for interaction), although the incidence of total bleeding was greater with ticagrelor aspirin than with clopidogrel aspirin among patients at low risk (p < 0.01 for interaction). Analysis in the per-protocol population yielded similar results.DiscussionThis post hoc analysis of CHANCE-2 trial showed that CYP2C19 LOF carriers with minor stroke or TIA at low risk of recurrent stroke received a greater benefit from ticagrelor aspirin than from clopidogrel aspirin.Classification of evidenceThis study provides Class II evidence that CYP2C19 LOF carriers with minor stroke or TIA at low risk, but not at high risk, of recurrent stroke (by the ESRS) received a greater benefit from ticagrelor aspirin than from clopidogrel aspirin.Trial registration informationURL: www.Clinicaltrialsgov. Unique identifier: NCT04078737.

Project description:Importance:Debate continues about the value of event adjudication in clinical trials and whether independent centralized assessments improve reliability and validity of study results in masked randomized trials compared with local, investigator-assessed end points. Objective:To assess the results of the adjudicated end point process in the Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) trial by comparing end points assessed by local site investigators with centrally adjudicated end points. Design, Setting, and Participants:This is an ad hoc secondary analysis of a randomized, double-blind clinical trial comparing safety and effectiveness of clopidogrel bisulphate plus aspirin vs placebo plus aspirin. Patients received either 600 mg of clopidogrel bisulphate on day 1, then 75 mg per day through day 90 plus 50 to 325 mg of aspirin per day, or the same range of dosages of placebo plus aspirin. Investigators reported all potential end points; independent masked adjudicators were randomly assigned to review using definitions specified in the study protocol. This was a multicenter study; 269 international sites in 10 countries enrolled from May 28, 2010, to December 19, 2017. The study enrolled 4881 patients 18 years or older with transient ischemic attack or minor acute ischemic stroke within 12 hours of symptom onset and followed for 90 days from randomization; last follow-up was completed in March 2018. Main Outcomes and Measures:Independent adjudicators external to the study and masked to study treatment assignment adjudicated 467 primary and secondary effectiveness outcomes and major and minor bleeding events, including the primary composite end point, which was the risk of a composite of major ischemic events at 90 days, defined as ischemic stroke, myocardial infarction, or death from an ischemic vascular event. The primary safety end point was major hemorrhage. All components of the primary and safety outcomes were adjudicated. Results:In this secondary analysis of an international randomized clinical trial, a total of 269 sites worldwide randomized 4881 patients (median age, 65.0 years; interquartile range, 55-74 years); 55.0% were male. The primary results have been published previously. The hazard ratios for clopidogrel plus aspirin vs placebo plus aspirin for the primary composite end point were 0.75 (95% CI, 0.59-0.95) for adjudicator-assessed events and 0.76 (95% CI, 0.60-0.95) for investigator-assessed events. Agreement between adjudicator and investigator assessments was 90.7%. The hazard ratios for clopidogrel plus aspirin vs placebo plus aspirin for the primary safety end point were 2.32 (95% CI, 1.10-4.87) for adjudicator-assessed events and 2.58 (95% CI, 1.19-5.58) for investigator-assessed events, with an agreement rate of 77.5%. Conclusions and Relevance:Independent end point adjudication did not substantially alter estimates of the primary treatment effectiveness in the POINT trial. Trial Registration:ClinicalTrials.gov identifier: NCT00991029.