Endovascular Treatment After Stroke Due to Large Vessel Occlusion for Patients Presenting Very Late From Time Last Known Well

Abstract

Importance: Endovascular treatment (EVT) after ischemic stroke due to emergent large vessel occlusion is usually constrained by a specific window of less than 16 to 24 hours from the time the patient was last known well (LKW). Patients with slow progression and tenacious collateral circulation may persist beyond 16 hours.

Objectives: To estimate the prevalence of salvageable tissues 16 hours or more from LKW after ischemic stroke due to emergent large vessel occlusion and investigate the effectiveness of EVT in delayed large vessel occlusion.

Design, setting and participants: In this case-control study, from a total of 8032 patients with stroke or transient ischemic attack who were admitted between January 1, 2012, and December 31, 2018, to a single referral university hospital, 150 patients were retrospectively identified who had an acute ischemic stroke with internal carotid artery or middle cerebral artery occlusion, had a baseline National Institutes of Health Stroke Scale score of 6 or more, and arrived 16 hours or more from time LKW. The decision for EVT was made by a treating physician according to the institutional protocol.

Main outcomes and measures: Baseline ischemic core, collateral circulation status, and computed tomographic or magnetic resonance perfusion parameters were retrospectively quantified. Follow-up images, evaluated a median of 93 hours (interquartile range, 66-120 hours) after arrival, were used to assess the final infarct and hemorrhagic transformation. The main outcome was the modified Rankin Scale score at 90 days.

Results: For 150 patients (81 men [54%]; mean [SD] age at onset, 70.1 [13.0] years; median National Institutes of Health Stroke Scale score, 12 [interquartile range, 8-18]), the median ischemic core volume was 11.5 mL (interquartile range, 0-39.1 mL), the median penumbra volume (>6 seconds) was 55.0 mL (interquartile range, 15-128 mL), and the median mismatch ratio was 4.0 (interquartile range, 0.9-18.3). By the imaging inclusion criteria for EVT trials, there were 50 DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-up and Late Presenting Strokes Undergoing Neurointervention With Trevo)-eligible patients (33%), 58 DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke)-eligible patients (39%), and 57 ESCAPE (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times)-eligible patients (38%). Endovascular treatment was performed for 24 patients (16%). In propensity score-matched analyses, EVT was associated with better odds of a 90-day modified Rankin Scale score of 0 to 2 (adjusted odds ratio, 11.08 [95% CI, 1.88-108.60]) and a 90-day modified Rankin Scale score shift (common adjusted odds ratio, 5.17 [95% CI, 1.80-15.62]). Type 2 parenchymal hemorrhage was seen in 3 of 24 patients (13%) who received EVT and in 4 of 126 patients (3%) who received medical management (adjusted odds ratio, 4.06 [95% CI, 0.63-26.30]). In a subgroup of 109 patients who were 24 hours from time LKW, EVT was associated with a favorable mRS shift (common adjusted odds ratio, 10.54 [95% CI, 2.18-59.34]).

Conclusions and relevance: This study suggests that patients with anterior circulation large vessel occlusion presenting very late (>16 hours to 10 days) from the time they were LKW may benefit from EVT.

Figure 1.. Effectiveness of Endovascular Treatment (EVT) in 3-Month Functional Recovery for Patients With Large Vessel Occlusion Who Presented in a Very Late Time Window

A, Distribution of modified Rankin Scale (mRS) scores at 3 months after stroke. B, Effectiveness of EVT at 3 months after stroke by delay from the time patient was last known well. Dotted lines indicate 95% CI.

Figure 2.. Benefit of Endovascular Recanalization According to Imaging Criteria of the Selected Endovascular Treatment (EVT) Trials

A, Modified Rankin Scale (mRS) score of 0-2 at 3 months after stroke. B, Favorable shift in mRS scores at 3 months after stroke. P values represent the statistical significance of the effect modifications according to trial eligibility. The eligibility according to the imaging criteria of selected trials was evaluated in 127 cases for the ESCAPE (Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times) trial, 150 cases for the DAWN (DWI or CTP Assessment with Clinical Mismatch in the Triage of Wake-up and Late Presenting Strokes Undergoing Neurointervention With Trevo) trial, and 109 cases for the DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke) trial. ^aThe odds ratios (ORs) and 95% CIs of EVT were from the main model without the propensity score matching.

Figure 3.. Comparison of Tissue Fate After Medical Management or Endovascular Treatment (EVT) in the Very Late Time Period

The final infarct growth from the baseline ischemic core as a ratio (A) and the final infarct growth from the baseline ischemic core as a volume (B) were similar. However, the extent of reperfused penumbra from the baseline penumbra volume greater than 6 seconds as a ratio (C) and the extent of reperfused penumbra from the baseline penumbra volume greater than 6 seconds as a volume (D) showed a trend toward a benefit of EVT. The thick horizontal line in the middle of the box denotes the median, boxes indicate the interquartile range, dots indicate individual extreme values out of the interquartile range, and curves indicate the probability density of the data at each y-axis, smoothed by a kernel density estimator.