Infarct Recurrence in Intracranial Atherosclerosis: Results from the MyRIAD Study

J Stroke Cerebrovasc Dis. 2021 Feb;30(2):105504. doi: 10.1016/j.jstrokecerebrovasdis.2020.105504. Epub 2020 Dec 1.


Background: Intracranial atherosclerotic disease (ICAD) is a common cause of ischemic stroke with a high risk of clinical stroke recurrence. Multiple mechanisms may underlie cerebral ischemia in this condition. The study's objective is to discern the mechanisms of recurrent ischemia in ICAD through imaging biomarkers of impaired antegrade flow, poor distal perfusion, abnormal vasoreactivity, and artery-to-artery embolism.

Methods: This prospective multicenter observational study enrolled patients with recent (≤21 days) ischemic stroke or transient ischemic attack (TIA) caused by ICAD with 50-99% stenosis treated medically. We obtained baseline quantitative MRA (QMRA), perfusion MRI (PWI), transcranial Doppler vasoreactivity (VMR), and emboli detection studies (EDS). The primary outcome was ischemic stroke in the territory of the stenotic artery within 1 year of follow-up; secondary outcomes were TIA at 1 year and new infarcts in the territory on MRI at 6-8 weeks.

Results: Amongst 102 of 105 participants with clinical follow-up (mean 253±131 days), the primary outcome occurred in 8.8% (12.7/100 patient-years), while 5.9% (8.5/100 patient-years) had a TIA. A new infarct in the territory of the symptomatic artery was noted in 24.7% at 6-8 weeks. A low flow state on QMRA was noted in 25.5%, poor distal perfusion on PWI in 43.5%, impaired vasoreactivity on VMR in 67.5%, and microemboli on EDS in 39.0%. No significant association was identified between these imaging biomarkers and primary or secondary outcomes.

Conclusions: Despite intensive medical management in ICAD, there is a high risk of clinical cerebrovascular events at 1 year and an even higher risk of new imaging-evident infarcts in the subacute period after index stroke. Hemodynamic and plaque instability biomarkers did not identify a higher risk group. Further work is needed to identify mechanisms of ischemic stroke and infarct recurrence and their consequence on long-term physical and cognitive outcomes.

Trial registration: NCT02121028.

Keywords: Biomarkers; Cerebral infarction; Intracranial arterial disease; Stroke.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Aged
  • Cerebrovascular Circulation
  • Female
  • Hemodynamics
  • Humans
  • Intracranial Arteriosclerosis / complications*
  • Intracranial Arteriosclerosis / diagnostic imaging
  • Intracranial Arteriosclerosis / physiopathology
  • Intracranial Embolism / diagnostic imaging
  • Intracranial Embolism / etiology*
  • Intracranial Embolism / physiopathology
  • Ischemic Attack, Transient / diagnostic imaging
  • Ischemic Attack, Transient / etiology*
  • Ischemic Attack, Transient / physiopathology
  • Ischemic Stroke / diagnostic imaging
  • Ischemic Stroke / etiology*
  • Ischemic Stroke / physiopathology
  • Male
  • Middle Aged
  • Plaque, Atherosclerotic
  • Prognosis
  • Prospective Studies
  • Recurrence
  • Risk Factors
  • Rupture, Spontaneous
  • Time Factors
  • Ultrasonography, Doppler, Transcranial
  • United States

Associated data