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CLEAR LVO

Reperfusion Without Functional Independence in Late Presentation of Stroke With Large Vessel Occlusion

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Year of Publication: 2022

Authors: Fatih Seker, Muhammad M. Qureshi, Markus A. Möhlenbruch, ..., Simon Nagel

Journal: Stroke

Citation: Stroke. 2022;53:3594–3604. doi:10.1161/STROKEAHA.122.039476

Link: https://www.ahajournals.org/doi/10.1161/STROKEAHA.122.039476

PDF: https://www.ahajournals.org/doi/pdf/10.1...EAHA.122.039476

Clinical Question

Does the imaging modality used for thrombectomy selection in the extended time window (CT vs CTP vs MRI) impact the rate of reperfusion without functional independence (RFI), symptomatic ICH, or mortality?

Bottom Line

Imaging modality (CT, CTP, MRI) did not influence the likelihood of RFI, sICH, or mortality after thrombectomy in the extended window. Risk was more dependent on age, stroke severity, and prestroke disability.

        Major Points
        Multicenter retrospective analysis of 715 patients with anterior circulation stroke treated with thrombectomy 6–24 hours from last seen well
All patients achieved mTICI 2c or 3 reperfusion
50.9% experienced RFI (mRS 3–6 at 90 days)
No significant difference in RFI by imaging modality (CT, CTP, MRI)
Older age, higher NIHSS, and higher prestroke mRS predicted both RFI and mortality; longer TLSW-to-puncture independently predicted RFI (but not mortality), and transfer to a comprehensive stroke center predicted both
Hypertension was associated with symptomatic ICH

      

Design

Study Type: Multicenter retrospective cohort

Randomization:

Blinding: Unblinded

Enrollment Period: January 2014 – December 2020

Follow-up Duration: 90 days

Centers: 15

Countries: 5

Sample Size: 715

Analysis: Multivariable regression with generalized estimating equations; multiple imputation for missing data; adjusted for age, NIHSS, mRS, comorbidities, occlusion site, ASPECTS, and time metrics

Inclusion Criteria

Acute ischemic stroke due to ICA, M1, or M2 occlusion
NIHSS ≥6
Prestroke mRS 0–2
Time-last-seen-well to treatment 6–24 hours
Successful reperfusion (mTICI 2c or 3)

Exclusion Criteria

mTICI 2b or lower reperfusion
Missing 90-day mRS data
Missing key covariates (e.g., ASPECTS, IV tPA status)

Baseline Characteristics

Age: Median 71 (IQR 59–81)

Sex - Female: 52.2%

Baseline NIHSS: Median 16 (IQR 11–20)

Prestroke mRS 0: 61.7%

Hypertension: 72.5%

Diabetes: 29.4%

Transferred from another hospital: 61.5%

ASPECTS: Mean 8.1 (SD 1.5)

Arms

Field	Control	CTP	MRI
Intervention	Noncontrast CT ± CTA for thrombectomy selection	CT perfusion including NCCT and CTA for thrombectomy selection	MRI with or without perfusion-weighted imaging for thrombectomy selection
Duration	Imaging modality used at presentation	Imaging modality used at presentation	Imaging modality used at presentation

Outcomes

Outcome	Type	Control	Intervention	P-value
Reperfusion without functional independence (mRS 3–6 at 90 days after mTICI 2c/3)	Primary	50.9% overall	No difference by imaging modality (CTP vs CT adj OR 1.11 [0.68–1.81]; MRI vs CT 0.73 [0.49–1.08])	CTP vs CT p=0.664; MRI vs CT p=0.115
Symptomatic intracranial hemorrhage	Secondary	5.2% overall	No difference by imaging type (CTP vs CT OR 0.77 [0.31–1.94]; MRI vs CT 0.71 [0.22–2.25])	CTP vs CT p=0.583; MRI vs CT p=0.560
90-day mortality	Secondary	17.8% overall	No difference by imaging type (CTP vs CT OR 1.48 [0.77–2.83]; MRI vs CT 1.04 [0.67–1.63])	CTP vs CT p=0.238; MRI vs CT p=0.853
Symptomatic Intracranial Hemorrhage	Adverse	5.2%	No difference by imaging (CTP vs CT OR 0.77 [0.31–1.94]; MRI vs CT 0.71 [0.22–2.25])	CTP vs CT p=0.583; MRI vs CT p=0.560; hypertension was the significant predictor (OR 2.41 [1.16–5.03] p=0.019)

Subgroup Analysis

Older age, higher NIHSS, prestroke mRS ≥1, lower ASPECTS, and ICA/M1 occlusion were associated with worse functional outcomes regardless of imaging modality

Criticisms

Retrospective, nonrandomized design
Imaging modality choice was site-dependent and not standardized
No data on patients not undergoing thrombectomy
No core/perfusion imaging parameters included
No adjustment for postprocedural variables like infarct size or anesthesia

Funding

Medtronic and the Society of Vascular and Interventional Neurology (SVIN)

Based on: CLEAR LVO (Stroke, 2022)