Stroke: does asymptomatic intracranial stenosis increase recurrence risk?

  • Hurford R & al.
  • JAMA Neurol
  • 26 May 2020

  • curated by Susan London
  • Clinical Essentials
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Takeaway

  • Patients with transient ischemic attack (TIA) or minor stroke who have isolated asymptomatic intracranial stenosis do not have elevated recurrence risk.

Why this matters

  • Asymptomatic intracranial stenosis is a common finding of unknown clinical importance. 
  • Editorial highlights the "good news" that with modern medical therapy, "asymptomatic intracranial stenosis is one less thing to worry about.”

Key results

  • 19.0% of patients had intracranial stenosis:
    • 4.2% had symptomatic stenoses.
    • 11.3% had asymptomatic stenoses.
    • 3.4% had both.
  • Prevalence of asymptomatic intracranial stenosis rose with age:
    • From 3.8% for age for trend<.001>
    • OR per decade of age: 1.96 (95% CI, 1.69-2.27).
  • Compared with peers with no intracranial stenosis, patients with asymptomatic disease did not have elevated risk for ischemic stroke:
    • Unadjusted HR, 1.03 (95% CI, 0.49-2.17).
    • Age-adjusted HR, 0.80 (95% CI, 0.38-1.71).
  • Midterm outcomes for this group:
    • 7-year risk for any recurrent ischemic stroke: 6.8%.
    • Annualized risk for same-territory ischemic stroke: 0.59%.

Study design

  • English population-based cohort study of 1579 patients (~95% white) with TIA or minor ischemic stroke (Oxford Vascular Study).
  • Intracranial stenosis: ≥50% narrowing on imaging (MRI/MRA in two-thirds).
  • Main outcome: prevalence, prognosis of asymptomatic intracranial stenosis.
  • Funding: The Wellcome Trust; Wolfson Foundation; others.

Limitations

  • Findings may not apply to nonwhite patients, major stroke.
  • Likely elevated medication adherence, risk factor control.
  • Excluded patients without intracranial vascular imaging.