Reviews/P2Y12 Antiplatelets/Clopidogrel-aspirin reduces stroke recurrence vs aspirin after TIA
Stroke · P2Y12-STR-01 · v2
Borderline: within 4 points of the Established/Likely boundary, so a re-grade could land either side.
Several large, well-conducted randomised trials compared clopidogrel plus aspirin against aspirin alone in people who had just had a minor stroke or a high-risk TIA, and they agreed: the combination lowered the chance of a further stroke or ischemic event over the following three months [4],[2],[5]. A pooled analysis that combined the individual patients from two of these trials reached the same conclusion [20]. The protection shows up almost entirely in the first few weeks, and the combination also raises the risk of serious bleeding [2],[5],[20]. The trials enrolled TIA patients alongside minor-stroke patients and did not report a TIA-only result, so the 'after TIA' part of the claim rests on a mixed population. One analysis found the benefit was absent in patients with established cardiovascular disease [1]. The consistency and size of the trials is why the panel treated the core effect as well supported despite these qualifications.
Three independent double-blind randomised trials report a lower risk of recurrent stroke or major ischemic events with clopidogrel-aspirin than with aspirin alone: CHANCE stroke 8.2% vs 11.7% (HR 0.68, 95% CI 0.57 to 0.81) [4], POINT major ischemic events 5.0% vs 6.5% (HR 0.75, 95% CI 0.59 to 0.95) [2], and INSPIRES new stroke 7.3% vs 9.2% (HR 0.79, 95% CI 0.66 to 0.94) [5]. A pooled individual-patient analysis of CHANCE and POINT (10,051 patients) found HR 0.70 (95% CI 0.61 to 0.81), concentrated in the first 21 days (HR 0.66, 95% CI 0.56 to 0.77) [20]. All of these populations enrolled high-risk TIA patients, though TIA was the qualifying event in a minority (13.1% in INSPIRES [5]). The same trials show more bleeding on the combination, with POINT major hemorrhage HR 2.32 (95% CI 1.10 to 4.87) [2] and INSPIRES moderate-to-severe bleeding HR 2.08 (95% CI 1.07 to 4.04) [5]. The contested point: The division is over the 'after TIA' population and over net benefit: no included trial reports a TIA-only recurrence estimate, and the effect that is reported is confined to the first weeks and carries a bleeding penalty [2],[5],[20],[19]. A post hoc INSPIRES analysis also found no benefit in patients with established cardiovascular disease (HR 0.97, 95% CI 0.73 to 1.28; P for interaction 0.04) [1].
All 21 papers behind this claim with their DOIs and what each does to it, the panel’s arbitration, the evidence gap map and the open research questions. Free, and sent to your inbox.
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One reviewer's only job is to attack the finding. The challenges below were weighed before the grade was set.
Every eligible trial enrolled a mixed minor-stroke + high-risk-TIA population; no included trial reports a TIA-only recurrence estimate, so the 'after TIA' claim is inferred from a subgroup never analysed in isolation.
The benefit is time-limited (confined to the first ~21 days in [20], first 2 weeks in [19]) and offset by increased major hemorrhage ([2] HR 2.32; [5] moderate-severe bleeding HR 2.08), so an unqualified 'reduces recurrence' overstates net benefit.
Where it remains uncertain. No trial isolates a TIA-only result, the benefit is time-limited and offset by increased major bleeding ([2] HR 2.32; [5] HR 2.08), and it was absent in the established-CVD subgroup ([1] HR 0.97).
Aleatory
Recurrence outcomes rest on relatively few events and confidence intervals are wide for subgroups, e.g. the established-CVD estimate [1] and the bleeding estimates [2],[5].
The load-bearing papers from a corpus of 21, each classified by what it does to the claim. Every DOI is taken from the corpus the claim was graded on.
Boundary condition: benefit attenuated in patients with established cardiovascular disease.
“DAPT was associated with a reduced risk of new stroke (hazard ratio [HR] = 0.67, 95%CI: 0.54-0.85, P < 0.001) in non-CVD patients but not in those with established CVD (HR = 0.97, 95%CI: 0.73-1.28, P = 0.82), compared with aspirin (P for interaction = 0.04).”
Panel auditInternal validity: medium · scope of inference: Patients with mild ischemic stroke or high-risk TIA of presumed atherosclerotic cause, stratified by prior cardiovascular disease.Key limitations: post hoc subgroup · TIA pooled with stroke · subgroup-dependent effect
POINT: independent international RCT confirming reduction in major ischemic events.
“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)”
Panel auditInternal validity: high · scope of inference: Patients with minor ischemic stroke or high-risk TIA, 90-day composite ischemic outcome; higher major hemorrhage.Key limitations: composite endpoint not pure stroke recurrence · TIA pooled with minor stroke · trial halted early · increased major hemorrhage
CHANCE: primary RCT showing clopidogrel-aspirin reduces 90-day stroke in TIA/minor stroke.
“Stroke occurred in 8.2% of patients in the clopidogrel-aspirin group, as compared with 11.7% of those in the aspirin group (hazard ratio, 0.68; 95% confidence interval, 0.57 to 0.81; P<0.001).”
Panel auditInternal validity: high · scope of inference: Chinese patients with minor ischemic stroke or high-risk TIA treated within 24 hours.Key limitations: TIA pooled with minor stroke · single-country (China) population
New stroke was lower with clopidogrel-aspirin across windows, reaching significance in the 48-72 hour group (HR 0.70, 95% CI 0.53-0.94).
Panel auditInternal validity: medium · scope of inference: Mild ischemic stroke or TIA within 72 hours, effect by initiation timing.Key limitations: subgroup analysis · TIA pooled with stroke · not all windows individually significant
4 of 21 papers shown. The full review lists all of them, with the panel’s arbitration →
Claims are graded at each quarterly release, and re-graded between releases only when a pivotal trial lands. Every change is a new version of the claim.
Multiple large, consistent, directly-on-point RCTs carry the effect, with only modest discount for mixed TIA/minor-stroke populations and time-limited, bleeding-offset benefit.
Release 2026-q4 re-graded every claim from its corpus under protocol v0.19. An earlier release's grade is shown for the record; it came from an earlier protocol and is not a movement.
Assumptions that carry weight but are not themselves established.
The panel records the gap that would most move the claim, and the study that would close it.
TIA-only recurrence estimate. Every included trial pools TIA with minor stroke and TIA is a minority of enrollment [5], so the 'after TIA' claim has no population-specific effect size. The panel rates this the highest-importance open gap for the claim, and names the study design that would close it: A prespecified TIA-only subgroup or a trial enrolling only high-risk TIA, reporting recurrent stroke and bleeding separately.
Open question: Does clopidogrel-aspirin reduce recurrent stroke in patients whose qualifying event was a TIA rather than a minor stroke? Why it is still open: No included trial reports a TIA-only recurrence estimate; TIA patients are pooled with minor stroke and form a minority of enrollment [4],[2],[5],[20].
Priors is a sceptical first reader, not peer review, and not medical advice.
Release 2026-q4 · graded 21 Oct 2026 · protocol v0.19