Advanced modality imaging evaluation in acute ischemic stroke may lead to delayed endovascular reperfusion therapy without improvement in clinical outcomes

Abstract

Purpose Advanced neuroimaging techniques may improve patient selection for endovascular stroke treatment but may also delay time to reperfusion. We studied the effect of advanced modality imaging with CT perfusion (CTP) or MRI compared with non-contrast CT (NCT) in a multicenter cohort. Materials and methods This is a retrospective study of 10 stroke centers who select patients for endovascular treatment using institutional protocols. Approval was obtained from each institution's review board as only de-identified information was used. We collected demographic and radiographic data, selected time intervals, and outcome data. ANOVA was used to compare the groups (NCT vs CTP vs MRI). Binary logistic regression analysis was performed to determine factors associated with a good clinical outcome. Results 556 patients were analyzed. Mean age was 66±15 years and median National Institutes of Health Stroke Scale score was 18 (IQR 14–22). NCT was used in 286 (51%) patients, CTP in 190 (34%) patients, and MRI in 80 (14%) patients. NCT patients had significantly lower median times to groin puncture (61 min, IQR (40–117)) compared with CTP (114 min, IQR (81–152)) or MRI (124 min, IQR (87–165)). There were no differences in clinical outcomes, hemorrhage rates, or final infarct volumes among the groups. Conclusions The current retrospective study shows that multimodal imaging may be associated with delays in treatment without reducing hemorrhage rates or improving clinical outcomes. This exploratory analysis suggests that prospective randomised studies are warranted to support the hypothesis that advanced modality imaging is superior to NCT in improving clinical outcomes.

CTA Collateral Status and Response to Recanalization in Patients with Acute Ischemic Stroke

“…MR imaging, however, takes time to screen, perform, and interpret. 19 Many patients do not tolerate it as well as CT; image quality is affected by patient motion. MR imaging also has limited availability "after hours."…”

“…Collateral status by use of the rLMC score (0 -20) was trichotomized into 3 groups: good (17)(18)(19)(20), intermediate (11)(12)(13)(14)(15)(16), and poor (0 -10), according to previously published literature. 3 Differences between these 3 groups were assessed by means of the Fisher exact test for proportions, 1-way ANOVA for parametric data, and a rank sum test for nonparametric data.…”

Perfusion-Based Selection for Endovascular Reperfusion Therapy in Anterior Circulation Acute Ischemic Stroke

“…5,8,9,11 Few studies have compared NCCT-based selection with perfusion imaging-based selection of patients for ERT following acute ischemic stroke. 12,13 We, therefore, sought to compare NCCT selection with perfusion imaging selection as a predictor of good outcome following ERT. We hypothesized that perfusion imaging-based selection would be associated with better functional outcomes at 3 months compared with NCCT-based selection alone.…”

Multimodal Diagnostic Imaging for Hyperacute Stroke

“…These delays of 18 -30 minutes may seem small, but when considering an emergency department arrival to groin puncture times of 95 minutes, the delays are significant. 19,20 In addition to delays, MR imaging is contraindicated in up to 20% of patients with acute stroke due to patient-related factors such as cardiac pacemakers and medical instability.…”

“…The only contraindication to CTA is a severe contrast allergy, in which case MRA can be performed but will potentially delay time-sensitive therapies by 18 -30 minutes. 19,20 Detection of Core and Penumbra. Patients with a large infarct core are unlikely to benefit from endovascular therapy.…”