Reclassification of Ischemic Stroke Etiological Subtypes on the Basis of High-Risk Nonstenosing Carotid Plaque

Useless. You suggest  doing nothing about preventing the next stroke when this is found. 

Reclassification of Ischemic Stroke Etiological Subtypes on the Basis of High-Risk Nonstenosing Carotid Plaque

Hooman Kamel

,

Babak B. Navi

,

Alexander E. Merkler

,

Hediyeh Baradaran

,

Iván Díaz

,

Neal S. Parikh

,

Scott E. Kasner

,

David J. Gladstone

,

Costantino Iadecola

,

Ajay Gupta

Originally published18 Dec 2019https://doi.org/10.1161/STROKEAHA.119.027970Stroke. ;0:STROKEAHA.119.027970

Abstract

Background and Purpose—

Carotid artery plaque with <50% luminal stenosis may be an underappreciated stroke mechanism. We assessed how many stroke causes might be reclassified after accounting for nonstenosing plaques with high-risk features.

Methods—

We included patients enrolled in the Cornell Acute Stroke Academic Registry from 2011 to 2015 who had anterior circulation infarction, magnetic resonance imaging of the brain, and magnetic resonance angiography of the neck. High-risk plaque was identified by intraplaque hemorrhage ascertained from routine neck magnetic resonance angiography studies using validated methods. Infarct location was determined from diffusion-weighted imaging. Intraplaque hemorrhage and infarct location were assessed separately in a blinded fashion by a neuroradiologist. We used the McNemar test for matched data to compare the prevalence of intraplaque hemorrhage ipsilateral versus contralateral to brain infarction. We reclassified stroke subtypes by including large-artery atherosclerosis as a cause if there was intraplaque hemorrhage ipsilateral to brain infarction, regardless of the degree of stenosis.

Results—

Among the 1721 acute ischemic stroke patients registered in the Cornell Acute Stroke Academic Registry from 2011 to 2015, 579 were eligible for this analysis. High-risk plaque was more common ipsilateral versus contralateral to brain infarction in large-artery atherosclerotic (risk ratio [RR], 3.7 [95% CI, 2.2–6.1]), cryptogenic (RR, 2.1 [95% CI, 1.4–3.1]), and cardioembolic strokes (RR, 1.7 [95% CI, 1.1–2.4]). There were nonsignificant ipsilateral-contralateral differences in high-risk plaque among lacunar strokes (RR, 1.2 [95% CI, 0.4–3.5]) and strokes of other determined cause (RR, 1.5 [95% CI, 0.7–3.3]). After accounting for ipsilateral high-risk plaque, 88 (15.2%) patients were reclassified: 38 (22.6%) cardioembolic to multiple potential etiologies, 6 (8.5%) lacunar to multiple, 3 (15.8%) other determined cause to multiple, and 41 (20.8%) cryptogenic to large-artery atherosclerosis.

Conclusions—

High-risk carotid plaque was more prevalent ipsilateral to brain infarction across several ischemic stroke subtypes. Accounting for such plaques may reclassify the etiologies of up to 15% of cases in our sample.

Footnotes

Guest Editor for this article was Stephen M. Davis, MD.
The online-only Data Supplement is available with this article at https://www.ahajournals.org/doi/suppl/10.1161/STROKEAHA.119.027970.

Correspondence to Hooman Kamel, MD, Clinical and Translational Neuroscience Unit, Feil Family Brain and Mind Research Institute and Department of Neurology, Weill Cornell Medicine, 420 E 70th St, LH-413, New York, NY 10021. Email hok9010@med.cornell.edu