# Impact of transport modality on time to endovascular thrombectomy: A population-based registry study in rural Sweden

## TL;DR

Using helicopters to transport rural stroke patients significantly reduces the time to receive life-saving treatment.

## Contribution

This study demonstrates that Helicopter Emergency Medical Services (HEMS) significantly reduce time to endovascular thrombectomy for rural stroke patients.

## Key findings

- HEMS transport reduced median dispatch-to-EVT time by over 60 minutes compared to ground transport for patients ≥50 km from a CSC.
- HEMS use was associated with a 3.6-fold higher likelihood of receiving EVT within the critical 180-minute window.
- Regional differences in transport strategies correlate with disparities in timely stroke treatment access.

## Abstract

Endovascular thrombectomy (EVT) is a time-critical treatment for acute ischemic stroke; however, timely access to comprehensive stroke centers (CSCs) is often limited by distance. Regional variations in prehospital transport strategies, particularly Helicopter Emergency Medical Services (HEMS) use, exist in Sweden, which may contribute to inequities in care. This study analyzed how transport modality affected the time to EVT for rural patients across two large Swedish regions with differing transport strategies.

A retrospective registry-based study was performed, using comprehensive stroke registries and ambulance records from 2018 to 2022. All patients who underwent EVT in two healthcare regions (Västra Götaland and Southeastern healthcare regions) were included. The primary analysis focused on those located ≥ 50 km from the CSC. The main outcome was the time from emergency medical service (EMS) dispatching to EVT start. Logistic regression was used to assess the odds of receiving EVT within 180 min.

Among the 1,222 patients, 623 (51%) were ≥ 50 km from a CSC. Direct CSC transfer and HEMS use were more frequent in Västra Götaland compared to the Southeastern region (52.0% vs. 28.4% and 8.9% vs. 0.9%, respectively; P < 0.001 and P = 0.003, respectively). For patients ≥ 50 km away, HEMS transport yielded a shorter median dispatch-to-EVT time than ground transport (224.2 vs 287.5 min; P < 0.001). After adjusting for distance, HEMS was associated with a 3.6-fold higher likelihood of EVT within 180 min (OR 3.6 [95% CI 1.6–7.8], P = 0.001).

Geographical distance significantly delays time to EVT. Use of HEMS markedly shortens transport time leading to timelier EVT for patients with long distances to CSC and has the potential to mitigate regional disparities. Integrating HEMS into stroke transport protocols is essential to ensure timely and equitable EVT access for rural patients.

The online version contains supplementary material available at 10.1186/s13049-026-01587-4.