PLATO
(2023)Objective
To compare clinical outcomes of endovascular therapy (EVT) versus medical management (MM) in patients with isolated posterior cerebral artery (PCA) occlusion presenting within 24 hours.
Study Summary
• EVT carried significantly higher sICH (6.2% vs 1.7%; aOR 3.11, P=0.014) and mortality (10.1% vs 5.0%; MV aOR 2.29, P=0.004).
• Functional independence was similar (~51–53%), reinforcing clinical equipoise and the need for ongoing randomized trials in PCA occlusion.
Intervention
Endovascular therapy (stent retriever, aspiration, or IA thrombolysis) ± IVT vs. medical management ± IVT
Inclusion Criteria
Age ≥18, isolated PCA occlusion (P1–P4, fetal, or bilateral), presentation within 24 hours, prestroke mRS 0–3
Study Design
Arms: EVT ± IVT vs. MM ± IVT
Patients per Arm: 1023 total (EVT: 378, MM: 645)
Outcome
• Secondary: Excellent outcome favored EVT (aOR 1.50, P=0.018); functional independence similar; complete vision recovery higher with EVT.
• Safety: sICH 3-fold higher with EVT (aOR 3.11, P=0.014); mortality higher (MV aOR 2.29, P=0.004).
Bottom Line
EVT did not improve overall disability by ordinal mRS shift or functional independence (mRS 0–2) compared to MM in isolated PCA occlusion. However, EVT was associated with higher odds of excellent outcome (mRS 0–1), early NIHSS improvement, and complete vision recovery, at the cost of significantly higher sICH and mortality rates.
Major Points
- No difference in 90-day ordinal mRS shift between EVT and MM (IPTW aOR 1.13, P=0.41).
- EVT associated with higher odds of ≥2-point NIHSS decrease (aOR 1.84, P=0.0001).
- EVT associated with higher likelihood of excellent outcome (mRS 0–1; aOR 1.50, P=0.018).
- Functional independence (mRS 0–2) similar between groups (51.0% vs 53.3%).
- Complete vision recovery significantly greater in EVT (70.2% vs 42.9%; P=0.002).
- sICH 3-fold higher with EVT (6.2% vs 1.7%; IPTW aOR 3.11, P=0.014).
- Mortality higher with EVT (10.1% vs 5.0%; MV aOR 2.29, P=0.004; IPTW aOR 1.67, P=0.082).
- Successful recanalization (mTICI ≥2b) achieved in 79.3% of EVT patients.
- Baseline visual field deficit present in 68.7% of patients overall.
- sICH rates were similar between P1 and P2 EVT patients (7% vs 6%), suggesting distal location does not explain hemorrhagic risk.
- Of 34 patients with sICH, 44.1% died.
- IVT administered in 42.9% overall with no difference between groups.
Study Design
- Study Type
- International, multicenter, retrospective cohort (case-control) study
- Randomization
- No
- Blinding
- Unblinded; 90-day mRS collected by site investigators/coordinators who could have been unblinded to treatment
- Sample Size
- 1023
- Follow-up
- 90 days
- Centers
- 27
- Countries
- USA, Switzerland, Finland, Germany, Spain, Portugal, Italy, Greece
Primary Outcome
Definition: Co-primary: (1) 90-day mRS ordinal shift; (2) ≥2-point decrease in NIHSS at 24 hours or discharge
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| (1) Median mRS 2 [1–3]; (2) 270/617 (43.8%) | (1) Median mRS 2 [1–4]; (2) 224/342 (65.5%) | - ((1) IPTW: 0.85–1.50; (2) IPTW: 1.35–2.52) | (1) IPTW P=0.413; (2) IPTW P=0.0001 |
Limitations & Criticisms
- Retrospective, non-randomized design with inherent selection bias.
- Unblinded outcome assessment (mRS, NIHSS).
- EVT group had higher baseline NIHSS and more proximal occlusions, creating confounding despite IPTW/MV adjustment.
- Vision recovery data missing in substantial proportion of patients with visual field defects (only 227/611 had follow-up data).
- Cognitive outcomes not assessed; PCA strokes can cause significant cognitive impairment.
- pc-ASPECTS was designed for basilar artery occlusion, not isolated PCA occlusion.
- No adjustment for multiple testing across secondary endpoints.
- Higher transfer rates in EVT group may introduce lead-time bias.
- No core lab for imaging adjudication.
- Complete case analysis without imputation for missing data.
- 3-fold higher sICH and doubled mortality in EVT group raise significant safety concerns for routine EVT in PCA occlusion.
Citation
Stroke. 2023;54:1708–1717. DOI: 10.1161/STROKEAHA.123.042674