Selection of Candidates for Endovascular Treatment: Characteristics According to Three Different Selection Methods

Abstract

Background and purpose: To investigate the number and characteristics of patients eligible for endovascular treatment (EVT) determined using three different selection methods clinical-core mismatch, target mismatch, and collateral status.

Methods: Using the data of consecutive patients from two prospectively maintained registries of university medical centers, the number and characteristics of patients according to the three selection methods were investigated and their correlation was analyzed. Patients with anterior circulation stroke due to occlusion of the middle cerebral and/or internal carotid artery and a National Institute of Health Stroke Scale (NIHSS) score of ≥6 points, who arrived within 8 hours or between 6 and 12 hours of symptom onset and underwent magnetic resonance imaging prior to EVT, were included. Collateral status was assessed using magnetic resonance perfusion-derived collateral flow maps.

Results: Three hundred thirty-five patients were investigated; the proportions of patients who were eligible and ineligible for EVT in all three selection methods were both small (n=85, 25.4%; n=54, 16.1%, respectively). The intercorrelation among the three selection methods was low (κ=0.235). The baseline NIHSS score and onset-to-selection time interval were associated with the presence of clinical-core mismatch, while the penumbra/core volume ratio and onset-to-selection time interval were related to target mismatch; none of these variables were associated with collateral status. The infarct core volume was associated with favorable profiles in all three selection methods.

Conclusion: s Although the application of individual selection methods resulted in favorable outcomes after EVT in clinical trials, there is a significant discrepancy in EVT eligibility depending on the selection method used.

Keywords: Collateral; Endovascular treatment; Mismatch; Selection.

Figure 1.

Number of patients with favorable and unfavorable profiles according to the three selection methods. (A) Samsung Medical Center cohort (onset-to-selection time interval, <8 hours), (B) Seoul National University Bundang Hospital cohort (onset-to-selection time interval, 6 to 12 hours). EVT, endovascular treatment.

Figure 2.

Typical examples of mismatch among the selection methods. Images of a 76-year-old man with left middle cerebral artery occlusion with an initial National Institutes of Health Stroke Scale score of 21 points and an onset-to-selection time interval of 520 minutes. The patient is classified as ineligible for endovascular treatment in the clinical-core mismatch selection method (A) but eligible in the target mismatch (A, B) and collateral status selection methods (C).