Clopidogrel Plus Aspirin Reduces Risk of Recurrent Stroke: The CHANCE Trial

Summary

Transient ischemic attack (TIA) and minor stroke are common cerebrovascular disorders after which there is a high risk of recurrent stroke. Results from the recently completed Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events study [CHANCE] indicate that an early period of clopidogrel plus aspirin reduces the risk of recurrent stroke in these patients without increasing bleeding compared with aspirin alone.

  • Thrombotic Disorders Clinical Trials
  • Episodic & Paroxysmal Disorders
  • Neurology
  • Thrombotic Disorders
  • Neurology Clinical Trials
  • Episodic & Paroxysmal Disorders

Transient ischemic attack (TIA) and minor stroke are common cerebrovascular disorders after which there is a high risk of recurrent stroke. Results from the recently completed Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events study [CHANCE] indicate that an early period of clopidogrel plus aspirin reduces the risk of recurrent stroke in these patients without increasing bleeding compared with aspirin alone.

The objective of the CHANCE study was to assess the effects an early 21-day period of clopidogrel plus aspirin versus aspirin alone on reducing the risk of a new stroke when initiated within 24 hours of symptom onset in patients with minor stroke (National Institutes of Health Stroke Score [NIHSS] ≤3) or TIA (ABCD2 score ≥4). The study design has been published [Wang Y et al. Am Heart J 2010]. Yongjun Wang, MD, Beijing Tian Tan Hospital, Beijing, China, presented the 3-month results.

Study participants (n=5170) were randomly assigned to receive clopidogrel (loading dose of 300 mg then 75 mg/day for up to 3 months) plus aspirin (75 mg/day for 21 days; n=2584) or aspirin (75 mg/day for 3 months) plus placebo (n=2586). The primary efficacy outcome was the percentage of new strokes (ischemic or hemorrhagic) at 3 months. The secondary efficacy outcome was a combination of new clinical vascular events (ischemic stroke, hemorrhagic stroke, myocardial infarction, or vascular death) at 3 months. The primary safety outcome was combined moderate and severe bleeding, according to the GUSTO definition. Other safety outcomes included intracranial hemorrhage, total mortality, and adverse events (including serious adverse events). Study visits were performed on the day of randomization at Day 21 and Day 90.

Subjects were mean 62.5 years of age and mostly men. Approximately 72% of the enrolled patients had minor stroke; mean time to randomization was 13 hours. At 3 months, the risk of recurrent stroke was significantly lower among patients assigned to clopidogrel plus aspirin compared with those receiving aspirin alone (HR, 0.68; 95% CI, 0.57 to 0.81; p<0.001). More patients on the dual regimen were also free of the secondary outcome of combined events (HR, 0.69; 95% CI, 0.58 to 0.82; p<0.001). Patients on the dual regimen were also less likely to experience a recurrent ischemic stroke (7.9% vs 11.4%; HR, 0.67; 95% CI, 0.56 to 0.81; p<0.0001). The differences on the remaining secondary outcomes of hemorrhagic stroke, myocardial infarction, and cardiovascular death were not statistically different. There was no difference in the rates of severe, moderate, or mild bleeding, or death from any cause. As the greatest separation of the 2 treatment arms appeared to occur during the first 21 days post stroke, the authors suggested that the early period of dual antiplatelet therapy may have been the major cause of superior outcome.

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