Nonstenotic Intracranial Plaques Common in Embolic Stroke of Undetermined Source

stroke caused by atherosclerosis
Nonstenotic intracranial plaque likely has an etiologic role in embolic stroke of undetermined source.

Nonstenotic intracranial plaque likely has an etiologic role in embolic stroke of undetermined source (ESUS), according to results of a retrospective study published in the Journal of the American College of Cardiology.

This study retrospectively enrolled patients (N=403) with small vessel disease (SVD; n=160) or ESUS (n=243) who were treated at the General Hospital of Northern Theater Command in China between 2015 and 2019. Study researchers performed a clinical assessment of plaque from magnetic resonance imaging (MRI) data included in patient medical records.

Ipsilateral and contralateral plaque characteristics did not differ significantly among patients with SVD. Among patients with ESUS, the ipsilateral and contralateral plaques differed for burden (63.8% vs 60.4%; P =.002), remodeling index (1.166 vs 1.091; P <.001), discontinuity of plaque surface (73.5% vs 59.6%; P =.018), and complicated plaque (76.8% vs 59.6%; P =.003), respectively.

Among patients with ESUS, 25.9% had only ipsilateral plaques, 4.9% only contralateral plaques, and 37.9% had bilateral plaques. Patients with ESUS were at increased risk for presenting with plaques (odds ratio [OR], 5.25; 95% CI, 2.83-9.73) and more nonstenotic intracranial plaques were seen in patients with ESUS (68.7%) compared with those with SVD (40.0%; P <.001).

In a multivariate regression analysis, increased remodeling index (per 0.1 increase) was found to be the only significant predictor of ESUS (odds ratio [OR], 2.295; 95% CI, 1.661-3.172; P <.001). A cutoff for remodeling index of 1.162 corresponded with an accurate ESUS prediction (area under the receiving operator characteristic curve [AUC], 0.740) and was not significantly improved by the addition of other clinical variables.

This study was limited by not having histologic validation data and by a possible underestimation of the remodeling index due to the role of atherosclerosis.

The study authors concluded that their study “provides the first evidence supporting an etiologic role for high-risk nonstenotic intracranial plaque in patients with ESUS.” They added, however, “The optimal preventive strategies in these patients remain unclear.”


Tao L, Li XQ, Hou XW, et al. Intracranial atherosclerotic plaque as a potential cause of embolic stroke of undetermined source. J Am Coll Cardiol. 2021;77(6):680-691. doi:10.1016/j.jacc.2020.12.015