Comparative Effectiveness of Dual Antiplatelet Therapy With Aspirin and Clopidogrel Versus Aspirin Monotherapy in Mild-to-Moderate Acute Ischemic Stroke According to the Risk of Recurrent Stroke: An Analysis of 15 000 Patients From a Nationwide, Multicenter Registry

Circ Cardiovasc Qual Outcomes. 2020 Nov;13(11):e006474. doi: 10.1161/CIRCOUTCOMES.119.006474. Epub 2020 Nov 17.

Abstract

Background: This study compared the effectiveness of dual antiplatelet therapy (DAPT) with clopidogrel-aspirin with that of aspirin monotherapy (AM) in mild-to-moderate acute ischemic stroke considering the risk of recurrent stroke using the Stroke Prognosis Instrument II (SPI-II) score.

Methods: This study is a retrospective analysis of data from a prospective, nationwide, multicenter stroke registry database between January 2011 and July 2018. We included patients with mild-to-moderate (National Institutes of Health Stroke Scale score ≤10), acute (within 24 hours of onset), noncardioembolic ischemic stroke. The primary outcome was a 3-month composite of stroke (either hemorrhagic or ischemic), myocardial infarction, and all-cause mortality. Propensity scores using the inverse probability of treatment weighting method were used to mitigate baseline imbalances between the DAPT and AM groups and within each subgroup considering SPI-II scores.

Results: Among the 15 430 patients (age, 66±13 years; men, 62.0%), 45.1% (n=6960) received DAPT and 54.9% (n=8470) received AM. Primary outcome events were significantly more frequent in the AM group (16.7%) than in the DAPT group (15.5%; P=0.03). Weighted Cox proportional hazards models showed a reduced risk of 3-month primary vascular events in the DAPT group versus the AM group (hazard ratio, 0.84 [0.78-0.92]; P<0.001), with no interaction between acute treatment type and SPI-II risk subgroups (Pinteraction=0.44). However, among the high-risk patients with SPI-II scores >7, a substantially larger absolute benefit was observed for 3-month composite vascular events in the DAPT group (weighted absolute risk differences, 5.4%), whereas smaller absolute benefits were observed among patients in the low- or medium-risk SPI-II subgroups (1.7% and 2.4%, respectively).

Conclusions: Treatment with clopidogrel-aspirin was associated with a reduction in 3-month vascular events compared with AM in mild-to-moderate acute noncardioembolic ischemic stroke patients. Larger magnitudes of the effects of DAPT with clopidogrel-aspirin were observed in the high-risk subgroup by SPI-II risk scores.

Keywords: aspirin; clopidogrel; prognosis; prospective studies; registries.

Publication types

  • Comparative Study
  • Multicenter Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aspirin / adverse effects
  • Aspirin / therapeutic use*
  • Clopidogrel / adverse effects
  • Clopidogrel / therapeutic use*
  • Comparative Effectiveness Research
  • Databases, Factual
  • Dual Anti-Platelet Therapy* / adverse effects
  • Dual Anti-Platelet Therapy* / mortality
  • Female
  • Hemorrhagic Stroke / mortality
  • Hemorrhagic Stroke / prevention & control
  • Humans
  • Ischemic Stroke / diagnosis
  • Ischemic Stroke / drug therapy*
  • Ischemic Stroke / mortality
  • Male
  • Middle Aged
  • Myocardial Infarction / mortality
  • Myocardial Infarction / prevention & control
  • Platelet Aggregation Inhibitors / adverse effects
  • Platelet Aggregation Inhibitors / therapeutic use*
  • Recurrence
  • Registries
  • Republic of Korea / epidemiology
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Severity of Illness Index
  • Time Factors
  • Treatment Outcome

Substances

  • Platelet Aggregation Inhibitors
  • Clopidogrel
  • Aspirin