Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial

BACKGROUND

The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized.

METHODS

SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined.

RESULTS

Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77).

CONCLUSIONS

ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

Sex differences in endovascular thrombectomy outcomes in large vessel occlusion: a propensity-matched analysis from the SELECT study

BACKGROUND

Sex disparities in acute ischemic stroke outcomes are well reported with IV thrombolysis. Despite several studies, there is still a lack of consensus on whether endovascular thrombectomy (EVT) outcomes differ between men and women.

OBJECTIVE

To compare sex differences in EVT outcomes at 90-day follow-up and assess whether progression in functional status from discharge to 90-day follow-up differs between men and women.

METHODS

From the Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT) prospective cohort study (2016-2018), adult men and women (≥18 years) with anterior circulation large vessel occlusion (internal carotid artery, middle cerebral artery M1/M2) treated with EVT up to 24 hours from last known well were matched using propensity scores. Discharge and 90-day modified Rankin Scale (mRS) scores were compared between men and women. Furthermore, we evaluated the improvement in mRS scores from discharge to 90 days in men and women using a repeated-measures, mixed-effects regression model.

RESULTS

Of 285 patients, 139 (48.8%) were women. Women were older with median (IQR) age 69 (57-81) years vs 64.5 (56-75), p=0.044, had smaller median perfusion deficits (Tmax >6 s) 109 vs 154 mL (p<0.001), and had better collaterals on CT angiography and CT perfusion but similar ischemic core size (relative cerebral blood flow <30%: 7.6 (0-25.2) vs 11.4 (0-38) mL, p=0.22). In 65 propensity-matched pairs, despite similar discharge functional independence rates (women: 42% vs men: 48%, aOR=0.55, 95% CI 0.18 to 1.69, p=0.30), women exhibited worse 90-day functional independence rates (women: 46% vs men: 60%, aOR=0.41, 95% CI 0.16 to 1.00, p=0.05). The reduction in mRS scores from discharge to 90 days also demonstrated a significantly larger improvement in men (discharge 2.49 and 90 days 1.88, improvement 0.61) than in women (discharge 2.52 and 90 days 2.44, improvement 0.08, p=0.036).

CONCLUSION

In a propensity-matched cohort from the SELECT study, women had similar discharge outcomes as men following EVT, but the improvement from discharge to 90 days was significantly worse in women, suggesting the influence of post-discharge factors. Further exploration of this phenomenon to identify target interventions is warranted.

TRIAL REGISTRATION NUMBER

NCT02446587.

EXPRESS: A Randomized Controlled Trial to Optimize Patientâs Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT2): Study Protocol

RATIONALE

Randomized evidence for endovascular thrombectomy(EVT) safety and efficacy in patients with large core strokes is lacking.

AIMS

To demonstrate EVT efficacy and safety in patients with large core on non-contrast CT or perfusion imaging(CT/MR) and determine if there is heterogeneity of treatment effect in large cores based on the imaging modality.

DESIGN

SELECT2 is a prospective, randomized, multi-center, assessor-blinded controlled trial with adaptive enrichment design, enrolling up to 560 patients.

PROCEDURE

Patients who meet the clinical criteria and have anterior circulation large vessel occlusions with large core on either NCCT(ASPECTS 3-5) or perfusion imaging(CTP[rCBF<30%] and/or MRI[ADC <620]â¥50cc) will be randomized in a 1:1 ratio to undergo EVT or medical management(MM) only up to 24 hours of last known well.

STUDY OUTCOMES

The distribution of 90-day mRS scores is the primary outcome. Functional independence(mRS=0-2) rate is a secondary outcome. Other secondary outcomes include safety(symptomatic ICH, neurological worsening, mortality) and imaging outcomes.

ANALYSIS

A normal approximation of the Wilcoxon-Mann-Whitney test(the generalized likelihood ratio test) to assess the primary outcome. Functional independence rates, safety and imaging outcomes will also be compared.

DISCUSSION

The SELECT2 trial will evaluate EVT safety and efficacy in large cores on either CT or perfusion imaging and may provide randomized evidence to extend EVT eligibility to larger population. Registration: ClinicalTrials.govâNCT03876457.

Endovascular thrombectomy in patients with large core ischemic stroke: a cost-effectiveness analysis from the SELECT study

Background

It is unknown whether endovascular thrombectomy (EVT) is cost effective in large ischemic core infarcts.

Methods

In the prospective, multicenter, cohort study of imaging selection study (SELECT), large core was defined as computed tomography (CT) ASPECTS<6 or computed tomography perfusion (CTP) ischemic core volume (rCBF<30%) ≥50 cc. A Markov model estimated costs, quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER) of EVT compared with medical management (MM) over lifetime. The willingness to pay (WTP) per QALY was set at $50 000 and $100 000 and the net monetary benefits (NMB) were calculated. Probabilistic sensitivity analysis (PSA) and cost-effectiveness acceptability curves (CEAC) for EVT were assessed in SELECT and other pivotal trials.

Results

From 361 patients enrolled in SELECT, 105 had large core on CT or CTP (EVT 62, MM 43). 19 (31%) EVT vs 6 (14%) MM patients achieved modified Rankin Scale (mRS) score 0–2 (OR 3.27, 95% CI 1.11 to 9.62, P=0.03) with a shift towards better mRS (cOR 2.12, 95% CI 1.05 to 4.31, P=0.04). Over the projected lifetime of patients presenting with large core, EVT led to incremental costs of $33 094 and a gain of 1.34 QALYs per patient, resulting in ICER of $24 665 per QALY. EVT has a higher NMB compared with MM at lower (EVT -$42 747, MM -$76 740) and upper (EVT $155 041, MM $57 134) WTP thresholds. PSA confirmed the results and CEAC showed 77% and 92% acceptability of EVT at the WTP of $50 000 and $100 000, respectively. EVT was associated with an increment of $29 225 in societal costs. The pivotal EVT trials (HERMES, DAWN, DEFUSE 3) were dominant in a sensitivity analysis at the same inputs, with societal cost-savings of $37 901, $86 164 and $22 501 and a gain of 1.62, 2.36 and 2.21 QALYs, respectively.

Conclusions

In a non-randomized prospective cohort study, EVT resulted in better outcomes in large core patients with higher QALYs, NMB and high cost-effectiveness acceptability rates at current WTP thresholds. Randomized trials are needed to confirm these results.

Clinical trial registration

NCT02446587

Triage imaging and outcome measures for large core stroke thrombectomy – a systematic review and meta-analysis

Background

Trials of endovascular thrombectomy (EVT) mostly excluded patients with large core strokes so the safety and efficacy of EVT is not well established in such patients. Moreover, the definition of large core and its measurement differ between semi-quantitative (ASPECTS) and quantitative (core volume) imaging modalities. We evaluated functional and safety outcomes in studies reporting large core stroke patients treated with EVT and compared them with patients treated with medical management (MM) only.

Methods

A systemic search using three large databases was performed to identify studies evaluating functional and safety outcomes in patients with large core strokes (ASPECTS<6 or core volume ≥50 cc) on CT, MRI, and Perfusion imaging according to PRISMA guidelines. A random-effect meta-analysis model was used to pool reported outcomes.

Results

Twelve studies reporting outcomes for patients treated with EVT compared with MM in large core strokes were included. A pooled random-effect meta-analysis of large core patients by either definition (ASPECTS <6 or ischemic core volume ≥50 cc or both) demonstrated increased functional independence (mRS-scores 0–2) rates with EVT (EVT: 122/491 (25%), MM: 45/691 (7%), pooled OR: 4.39 [95% CI: 2.53 to 7.64], overall effect Z-score: 5.25, P<0.00001, I2=37%, P for Cochran Q:0.15) and decreased mortality (EVT: 101/439 (23%), MM: 215/645 (33%), pooled OR:0.53 [95% CI: 0.40 to 0.71], overall effect Z-score:4.32, P<0.0001, I2=0%, P for Cochran Q:0.78) at 90 days, without significant increase in symptomatic intracranial hemorrhage (ICH) (EVT: 42/462 (9%), MM: 35/663 (5%), pooled OR: 1.68 [95% CI: 0.92 to 3.09], overall effect Z-score:1.68, P=0.09, I2=26%, P for Cochran Q:0.24). Similar effects were observed in studies reporting large core outcomes based on ASPECTS <6 and ischemic core volume ≥50 cc. We observed no heterogeneity between quantitative vs semi-quantitative large core definitions, different ischemic core thresholds, and studies reporting outcomes over different time windows in subgroup analyses.

Conclusion

In large core stroke patients, EVT is associated with improved functional independence and lower mortality at 90 days without significant increase in symptomatic ICH across various definitions, thresholds of large core size, and time windows. Further randomized evidence is warranted to establish EVT efficacy and safety in this population.