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ORIENTAL MEVO

Year of Publication: 2025

Authors: Raul Nogueira, Xiao-Zhong Jing, Wei Hu

Journal: Not published yet

Clinical Question

Does thrombectomy improve functional outcomes compared to medical management alone in patients with medium vessel occlusion stroke and moderate-to-severe deficits (NIHSS ≥6) presenting within 24 hours?

Bottom Line

Thrombectomy significantly improved functional independence (mRS 0–2) and excellent outcome (mRS 0–1) at 90 days compared to medical management alone in MeVO stroke patients with NIHSS ≥6, with an NNT of 8 and no significant increase in sICH or mortality. Benefit was not seen in the NIHSS <8 subgroup.

        Major Points
        First positive RCT for thrombectomy in MeVO stroke, targeting patients with NIHSS ≥6 — a key design difference from neutral trials DISTAL and ESCAPE-MeVO.
Primary endpoint of ordinal mRS shift violated the proportional odds assumption; prespecified alternative of 90-day mRS 0–2 showed significant benefit (58.6% vs 46.6%; aRR 1.24, P=0.004).
Median 90-day mRS was 2 in thrombectomy group vs 3 in medical management group.
Excellent outcome (mRS 0–1) also significantly favored thrombectomy (48.9% vs 33.2%; aRR 1.47, P<0.001).
Successful reperfusion (eTICI 2b–3) achieved in 74.4% of thrombectomy patients.
Vessel patency at 24–72 hours was 82.1% vs 46.2% favoring thrombectomy.
sICH was numerically higher but not statistically different (4.7% vs 2.2%).
Mortality was comparable (11.1% vs 10.2%).
No benefit of thrombectomy observed in NIHSS <8 subgroup, corroborating findings from ESCAPE-MeVO and DISTAL.
ACA and PCA occlusions combined exceeded 40% of the cohort, indicating substantial posterior and anterior distal territory representation.
IVT rates were below 40% in both groups.
NNT of 8 for functional independence; per 100 treated, 54 had less disability and 12 additional achieved mRS 0–2.

      

Design

Study Type: Investigator-initiated, prospective, open-label, randomized controlled trial

Randomization: 1

Blinding: Open-label (unblinded)

Follow-up Duration: 90 days

Centers: 48

Countries: China

Sample Size: 563

Analysis: Intention-to-treat. Ordinal mRS shift prespecified as primary but proportional odds assumption was violated, triggering prespecified alternative of mRS 0–2 as primary. Adjusted risk ratios reported.

Inclusion Criteria

Ischemic stroke due to MeVO (co-dominant or non-dominant M2, M3 of MCA; A1, A2, A3 of ACA; P1, P2, P3 of PCA)
Baseline NIHSS score ≥6
Presentation within 24 hours of symptom onset

Arms

Field	Thrombectomy + Medical Management	Control
Intervention	Mechanical thrombectomy plus standard medical management	Standard medical management alone (including IVT when eligible)
Duration

Outcomes

Outcome	Type	Control	Intervention	HR / OR / RR	P-value
90-day mRS 0–2 (prespecified alternative after proportional odds violation for ordinal mRS shift)	Primary	46.6%	58.6%	9	P=0.004
Excellent outcome (mRS 0–1 at 90 days)	Secondary	33.2%	48.9%	aRR 1.47	P<0.001
Vessel patency at 24–72 hours	Secondary	46.2%	82.1%
Ordinal mRS shift (prespecified primary — invalidated)	Secondary	Median mRS 3	Median mRS 2	Proportional odds assumption violated; common OR not reported
Symptomatic ICH	Adverse	2.2%	4.7%		NS
Mortality	Adverse	10.2%	11.1%		NS
Radiological ICH (24–72h)	Adverse	6.0%	11.4%

Subgroup Analysis

No significant benefit of thrombectomy in patients with NIHSS <8, consistent with findings from the negative ESCAPE-MeVO and DISTAL trials. This supports targeting thrombectomy to MeVO patients with moderate-to-severe deficits.

Criticisms

Open-label design with no blinding of patients, clinicians, or outcome assessors.
Proportional odds assumption violated for the prespecified primary endpoint (ordinal mRS shift), requiring switch to the prespecified alternative (mRS 0–2).
Conducted exclusively in China (48 sites), which may limit generalizability to other healthcare systems and ethnic populations.
IVT rates below 40% in both groups — lower than many Western practice settings.
Successful reperfusion rate (eTICI 2b–3) of 74.4% is lower than in LVO thrombectomy trials (typically >85%).
Baseline characteristics details limited (derived from conference presentation, not full manuscript).
ACA and PCA occlusions made up >40% of the cohort, mixing heterogeneous vascular territories.
No NIHSS ≥6 threshold validation as the optimal cutoff for MeVO thrombectomy benefit.
Numerically higher sICH (4.7% vs 2.2%) and radiological ICH (11.4% vs 6.0%) in thrombectomy arm, though not statistically significant.
Full manuscript with detailed baseline tables, subgroup analyses, and per-protocol results not yet available.

Based on: ORIENTAL MEVO (Not published yet, 2025)

Authors: Raul Nogueira, Xiao-Zhong Jing, Wei Hu

Content summarized and formatted by NeuroTrials.ai.

ORIENTAL MEVO

(2025)

Objective

To compare thrombectomy plus standard medical management versus medical management alone in patients with medium vessel occlusion (MeVO) stroke and baseline NIHSS ≥6, presenting within 24 hours.

Study Summary

• Thrombectomy significantly improved 90-day functional independence (mRS 0–2: 58.6% vs 46.6%; aRR 1.24, P=0.004) and excellent outcome (mRS 0–1: 48.9% vs 33.2%; aRR 1.47, P<0.001) compared to medical management alone, with NNT of 8.
• Safety was comparable between groups, with no significant differences in sICH (4.7% vs 2.2%) or mortality (11.1% vs 10.2%).
• No benefit was observed in the NIHSS <8 subgroup, consistent with prior neutral trials (DISTAL, ESCAPE-MeVO) that enrolled lower-severity patients.

Intervention

Thrombectomy + standard medical management vs. standard medical management alone

Inclusion Criteria

Ischemic stroke due to MeVO (M2 co/non-dominant, M3, A1–A3, P1–P3), baseline NIHSS ≥6, presentation within 24 hours of symptom onset

Study Design

Arms: Thrombectomy + medical management vs. medical management alone

Patients per Arm: 563 total (Thrombectomy: 280, Medical management: 283)

Outcome

• Primary: Proportional odds violated for ordinal mRS shift; prespecified alternative of mRS 0–2 at 90 days favored thrombectomy (58.6% vs 46.6%; aRR 1.24, P=0.004).
• Secondary: mRS 0–1 favored thrombectomy (48.9% vs 33.2%; aRR 1.47, P<0.001); vessel patency at 24–72h: 82.1% vs 46.2%; eTICI 2b–3 achieved in 74.4%.
• Safety: sICH 4.7% vs 2.2% (NS); mortality 11.1% vs 10.2% (NS); radiological ICH 11.4% vs 6.0%.

Bottom Line

Major Points

First positive RCT for thrombectomy in MeVO stroke, targeting patients with NIHSS ≥6 — a key design difference from neutral trials DISTAL and ESCAPE-MeVO.
Primary endpoint of ordinal mRS shift violated the proportional odds assumption; prespecified alternative of 90-day mRS 0–2 showed significant benefit (58.6% vs 46.6%; aRR 1.24, P=0.004).
Median 90-day mRS was 2 in thrombectomy group vs 3 in medical management group.
Excellent outcome (mRS 0–1) also significantly favored thrombectomy (48.9% vs 33.2%; aRR 1.47, P<0.001).
Successful reperfusion (eTICI 2b–3) achieved in 74.4% of thrombectomy patients.
Vessel patency at 24–72 hours was 82.1% vs 46.2% favoring thrombectomy.
sICH was numerically higher but not statistically different (4.7% vs 2.2%).
Mortality was comparable (11.1% vs 10.2%).
No benefit of thrombectomy observed in NIHSS <8 subgroup, corroborating findings from ESCAPE-MeVO and DISTAL.
ACA and PCA occlusions combined exceeded 40% of the cohort, indicating substantial posterior and anterior distal territory representation.
IVT rates were below 40% in both groups.
NNT of 8 for functional independence; per 100 treated, 54 had less disability and 12 additional achieved mRS 0–2.

Study Design

Study Type: Investigator-initiated, prospective, open-label, randomized controlled trial
Randomization: Yes
Blinding: Open-label (unblinded)
Sample Size: 563
Follow-up: 90 days
Centers: 48
Countries: China

Primary Outcome

Definition: 90-day mRS 0–2 (prespecified alternative after proportional odds violation for ordinal mRS shift)

Control	Intervention	HR/OR	P-value
46.6%	58.6%	-	P=0.004

Limitations & Criticisms

Open-label design with no blinding of patients, clinicians, or outcome assessors.
Proportional odds assumption violated for the prespecified primary endpoint (ordinal mRS shift), requiring switch to the prespecified alternative (mRS 0–2).
Conducted exclusively in China (48 sites), which may limit generalizability to other healthcare systems and ethnic populations.
IVT rates below 40% in both groups — lower than many Western practice settings.
Successful reperfusion rate (eTICI 2b–3) of 74.4% is lower than in LVO thrombectomy trials (typically >85%).
Baseline characteristics details limited (derived from conference presentation, not full manuscript).
ACA and PCA occlusions made up >40% of the cohort, mixing heterogeneous vascular territories.
No NIHSS ≥6 threshold validation as the optimal cutoff for MeVO thrombectomy benefit.
Numerically higher sICH (4.7% vs 2.2%) and radiological ICH (11.4% vs 6.0%) in thrombectomy arm, though not statistically significant.
Full manuscript with detailed baseline tables, subgroup analyses, and per-protocol results not yet available.

ORIENTAL MEVO

ORIENTAL MEVO

Clinical Question

Bottom Line

Major Points

Design

Inclusion Criteria

Arms

Outcomes

Subgroup Analysis

Criticisms

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