Optimizing Head Positioning in Large Vessel Occlusion Stroke Before Thrombectomy: Evidence from a Randomized Clinical Trial

Highlight

• A randomized clinical trial compared 0° versus 30° head positioning in patients with acute large vessel occlusion (LVO) stroke awaiting thrombectomy.
• 0° positioning significantly maintained neurological stability, reducing NIHSS worsened score events before thrombectomy versus 30° elevation.
• 30° head elevation was associated with higher risk of neurological deterioration, increased mortality at 3 months but no differences in hospital-acquired pneumonia.
• Findings support 0° head positioning as a protective measure while awaiting definitive mechanical thrombectomy treatment.

Study Background and Disease Burden

Acute ischemic stroke due to large vessel occlusion (LVO) represents a significant proportion of disabling strokes worldwide and is associated with high morbidity and mortality if revascularization is delayed. Mechanical thrombectomy, the endovascular removal of the occlusive clot, has become the standard of care within a specific time window. However, optimizing supportive care in the interval before thrombectomy may improve neurological outcomes by preserving the ischemic penumbra—the area of salvageable brain tissue.

Prior research, primarily small observational studies, suggested that the patient’s head position affects cerebral hemodynamics, with a flat (0°) head-of-bed position potentially enhancing collateral blood flow and penumbral perfusion. Many stroke centers currently use a 30° head elevation to reduce aspiration risks and intracranial pressure, but the clinical benefits or harms regarding neurological stability remain unclear. Establishing evidence-based head positioning protocols could improve outcomes during the critical prethrombectomy phase.

Study Design

This prospective, blinded randomized clinical trial was conducted from May 2018 to November 2023 at certified thrombectomy centers across the United States. The trial enrolled consecutive consenting adult patients who:

– Had ischemic stroke with anterior or posterior circulation LVO confirmed by computed tomography angiography (CTA).
– Were eligible for mechanical thrombectomy.
– Had baseline modified Rankin Scale scores of 0 to 1 (indicating no or minimal pre-stroke disability).
– Demonstrated viable ischemic penumbra (CT perfusion or Alberta Stroke Program Early CT Score ≥6).
– Were within 24 hours of stroke symptom onset.

Exclusion criteria included inability to obtain consent (e.g., patients with severe disabilities without legal representatives) and delayed systemic thrombolysis beyond 15 minutes after consent to minimize confounding.

Randomization assigned patients to either 0° (flat) or 30° head-of-bed positioning immediately after enrollment, sustained until transfer to the catheterization laboratory for thrombectomy. Neurological status was assessed every 10 minutes using the National Institutes of Health Stroke Scale (NIHSS).

Primary outcome was defined as worsening by 2 or more points on NIHSS before thrombectomy. Secondary safety outcomes included severe neurological deterioration (worsening of 4 or more NIHSS points), hospital-acquired pneumonia (HAP), and all-cause mortality within 3 months.

Key Findings

The study planned to enroll 182 participants but was closed early by the data and safety monitoring board after randomizing 92 patients due to significant outcomes:

– Patients’ mean age was 66.6 years, with 52.2% males, and baseline characteristics were similar between groups.
– Among 45 patients in the 0° position group and 47 in the 30° group:
– Worsening by ≥2 NIHSS points occurred significantly more in the 30° group; hazard ratio (HR) for worsening NIHSS was 34.40 (95% CI, 4.65–254.37; P < .001), indicating markedly higher risk with 30° elevation.
– Severe neurological deterioration (≥4-point worsening) was reported in 20 patients with 30° vs. 1 patient with 0° head position (HR, 23.57; 95% CI, 3.16–175.99; P = .002).
– No cases of hospital-acquired pneumonia were observed in either group.
– Mortality at 3 months was significantly lower in 0° group (4.4%) compared to 30° group (21.7%; P = .03).

These data strongly suggest that a flat head-of-bed position preserves neurological function and improves survival in acute LVO stroke patients while awaiting thrombectomy.

Expert Commentary

The findings from this rigorously conducted randomized trial provide high-quality evidence supporting a shift in routine supportive care for LVO stroke patients. Previously, standard practice of elevating the head of bed by 30° was grounded largely on extrapolations regarding aspiration pneumonia risk and intracranial pressure management rather than direct neurological benefit.

Mechanistically, flat positioning likely enhances collateral cerebral blood flow to the ischemic penumbra by reducing gravitational resistance, thereby sustaining neuronal viability. This concept aligns with physiological principles and prior hemodynamic studies but now has robust clinical outcome support.

The trial’s early termination underscores the magnitude of difference in neurological deterioration, buttressing clinical equipoise and safety concerns about continued 30° elevation.

Limitations include the early closure potentially reducing power to detect less common adverse events such as aspiration pneumonia. Additionally, the exclusion of patients unable to consent may limit generalizability to more disabled or older populations. Future studies might elucidate whether these findings apply beyond the time windows or stroke subtypes studied.

Conclusion

Optimal patient positioning prior to thrombectomy in LVO stroke is a crucial element of acute management. This randomized trial identifies 0° head-of-bed positioning as a superior strategy for maintaining neurological stability and reducing mortality during the prethrombectomy phase.

Stroke centers should consider revising protocols to embrace flat head positioning, balancing risks and benefits on an individualized basis. Further research might explore integration with other supportive measures, long-term functional outcomes, and broader patient populations.

References

Alexandrov AW, Shearin AJ, Mandava P, Torrealba-Acosta G, Elangovan C, Krishnaiah B, Nearing K, Robinson E, Guthrie-Chu C, Holzmann M, Fill B, Trivedi DR, Richardson A, Middleton S, Brewer BB, Liebeskind DS, Goyal N, Grotta JC, Alexandrov AV; ZODIAC Investigators. Optimal Head-of-Bed Positioning Before Thrombectomy in Large Vessel Occlusion Stroke: A Randomized Clinical Trial. JAMA Neurol. 2025 Sep 1;82(9):905-914. doi: 10.1001/jamaneurol.2025.2253. PMID: 40465238; PMCID: PMC12138796.