To Do or Not to Do; Dilemma of Intra-Arterial Revascularization in Acute Ischemic Stroke

<div><p>Background</p><p>There has still been lack of evidence for definite imaging criteria of intra-arterial revascularization (IAR). Therefore, IAR selection is left largely to individual clinicians. In this study, we sought to investigate the overall agreement of IAR selection among different stroke clinicians and factors associated with good agreement of IAR selection.</p><p>Methods</p><p>From the prospectively registered data base of a tertiary hospital, we identified consecutive patients with acute ischemic stroke. IAR selection based on the provided magnetic resonance imaging (MRI) results and clinical information were independently performed by 5 independent stroke physicians currently working at 4 different university hospitals. MRI results were also reviewed by 2 independent experienced neurologists blinded to clinical data and physicians' IAR selection. The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) was calculated on initial DWI and MTT. We arbitrarily used ASPECTS differences between DWI and MTT (D-M ASPECTS) to quantitatively evaluate mismatch.</p><p>Results</p><p>The overall interobserver agreement of IAR selection was fair (kappa = 0.398). In patients with DWI-ASPECTS >6, interobserver agreement was moderate to substantial (0.398–0.620). In patients with D-M ASPECTS >4, interobserver agreement was moderate to almost perfect (0.532–1.000). Patients with higher DWI or D-M ASPECTS had better agreement of IAR selection.</p><p>Conclusion</p><p>Our study showed that DWI-ASPSECTS >6 and D-M ASPECTS >4 had moderate to substantial agreement of IAR selection among different stroke physicians. However, there is still poor agreement as to whether IAR should not be performed in patients with lower DWI and D-M ASPECTS.</p></div

The general characteristics of the 3 groups according to the proportion of physicians who selected IAR.

<p>Abbreviations: FAT; first known abnormal time, FLAIR; Fluid-attenuated inversion recovery, PVWMH; periventricular white matter hyperintensity, M2; M2 segment of middle cerebral artery. ICA; internal carotid artery, dICA; distal ICA, M1; M1 segment of middle cerebral artery, M2; M2 segment of middle cerebral artery, DWI; diffusion-weighted imaging, ASPECTS; Alberta Stroke Program Early Computed Tomography Score, MTT; mean transit time, D-M ASPECTS; ASPECTS differences between DWI and MTT.</p

Comparisons of outcomes according to IAR treatment in patients of each group.

<p>Abbreviations: IVT, Intravenous thrombolysis; HT, hemorrhagic transformation; HI, hemorrhagic infarction; PH, parenchymal hemorrhage; mRS, modified Rankin Scale.</p><p>*P<0.05 (OR, 6.059; 95% CI, 1.003–36.583) by multivariate logistic regression analysis, adjusted by age and initial NIHSS.</p

The general characteristics of the subjects.

<p>Abbreviations: ICA; internal carotid artery, M1; M1 segment of middle cerebral artery, M2; M2 segment of middle cerebral artery, FAT; first known abnormal time, IVT; intravenous thrombolysis, IAR; intra-arterial revascularization.</p

Interobserver agreement of IAR selection between 5 clinicians for 125 stroke patients.

<p>The level of agreement is represented by kappa (κ) value calculated using DWI, MTT, and D-M ASPECTS.</p><p>Abbreviations: DWI; diffusion-weighted imaging, ASPECTS; Alberta Stroke Program Early Computed Tomography Score, MTT; mean transit time, D-M ASPECTS; ASPECTS differences between DWI and MTT.</p

Representative cases of lesion patterns of poor agreements for IAR (A, group B) and lesion patterns with good agreement for IAR decision (B, group C).

<p>(A) The figures show moderate sized lesions of right hemisphere on DWI, occlusion of right distal internal carotid artery, and large perfusion deficit on PWI. (B) The figures show small lesion of basal ganglia on DWI, occlusion of right internal carotid artery, and large hemispheric perfusion deficit on PWI.</p