Pre-Procedural Computed Tomography Angiogram for Patients Transferred for Thrombectomy: Can We Minimize Costs?

Area of Science:

• Neurology
• Interventional Radiology
• Health Economics

Background:

• Large vessel occlusion (LVO) stroke patients often require transfer for endovascular thrombectomy (EVT).
• Previous research indicated a ≥33% improvement in National Institute of Health Stroke Scale (NIHSS) score correlates with early recanalization, potentially negating the need for EVT.
• This study aimed to validate this NIHSS improvement correlation and evaluate cost-effectiveness of non-invasive imaging before digital subtraction angiography (DSA).

Purpose of the Study:

• To validate the correlation between ≥33% NIHSS score improvement and early recanalization in LVO stroke patients.
• To assess potential cost savings by implementing non-invasive imaging prior to DSA in transferred LVO stroke patients.
• To determine the optimal threshold for predicting early recanalization based on NIHSS score changes.

Main Methods:

• Retrospective analysis of 257 LVO stroke patients transferred for EVT between January 2023 and April 2024.
• Collected data included NIHSS changes, demographics, treatments, and anatomical factors.
• Correlated NIHSS changes with early recanalization and calculated hyperacute investigation and DSA costs.

Main Results:

• A ≥33% NIHSS improvement threshold demonstrated the best sensitivity (74%) and specificity (88%) for predicting early recanalization, identified in 11% of patients who avoided EVT.
• Implementing non-invasive imaging prior to DSA for patients with ≥33% NIHSS improvement resulted in modest cost savings of AUD 34 per patient.
• The median NIHSS score at presentation was 14, with 50% of patients receiving intravenous thrombolytics.

Conclusions:

• The ≥33% neurological recovery threshold effectively predicts early recanalization in LVO stroke patients.
• While cost savings were modest in this study, the strategy may be more significant in resource-limited settings.
• This approach can help optimize treatment pathways and resource allocation for LVO stroke patients.