“Letter to the Editor: A Transfer Strategy Utilizing a Helicopter and a Ground Ambulance Together Does Not Prolong Door-In-Door-Out Times in Thrombectomy Patients: A Retrospective Analysis”

Abstract

We read with great interest the article written by Vuorinen et al. titled “A Transfer Strategy Utilizing a Helicopter and a Ground Ambulance Together Does Not Prolong Door-In- Door Out Times in Thrombectomy Patients: A Retrospective Analysis” [1], which evaluates the logistics of stroke transfers utilizing a hybrid transport approach. While the study significantly advances the field, we would like to highlight a few limitations and contradictions that, if addressed, could enhance the robustness of the study.

The study appropriately focuses on process efficiency, that is, the DIDO (Door-In-Door-Out) time. However, it does not address its clinical outcomes, whether reducing DIDO time improved patient survival, neurological recovery, functional status (mRS ≤ 2), or quality of life. Such costly healthcare decisions, such as deploying helicopters, must be based on patient-centered clinical outcomes. Another study evaluated the significant impact of reduced DIDO time on functional clinical outcomes in patients having large vessel occlusion strokes and undergoing thrombectomy [2]. Including such outcome analysis would increase the clinical relevance and applicability of the study.

Secondly, the study analyzes whether using both ground ambulances and helicopters to move thrombectomy patients causes a delay in the DIDO time at the primary stroke center.

However, the study does not stratify or analyze patients according to their estimated travel times or distance from the thrombectomy center. Regardless of time travel or distance, it treats every patient in equal measure. HEMS' importance usually varies greatly with distance. A helicopter might not save enough time to be worth using if the patients are transferred straight from the scene or over short distances [3]. Moreover, HEMS is costly and may not be helpful if the patients live far from the thrombectomy center. McMeekin et al. (2021) concluded that helicopter transfers are only cost-effective if they save at least 60 min compared to ground transport [4].

Moreover, since DIDO time directly affects the results for patients requiring thrombectomy, it is often recognized as an important indicator in acute stroke therapy. Established clinical protocols emphasize that reducing DIDO is essential because delays can have a major impact on recovery from stroke. However, this study shows no association between the period of DIDO and the administration of thrombolysis (p = 0.64). This result contrasts with other studies, such as Prabhakaran et al. (Ann Emerg Med. 2021), which found that thrombolysis improves in-hospital workflow and typically cuts DIDO by 28 to 45 min [5]. The research does not address potential reasons for this divergence, even though local methods, workflow variations, or sample size may impact these findings. To achieve optimal stroke transfer methods and enhance patient outcomes, we encourage the authors to elaborate on factors that might explain this difference from established literature.

Nevertheless, we commend the authors for conducting this impactful study. However, we believe that considering the aforementioned points will increase the robustness, clinical applicability, and generalizability of future studies.

Noor Un Nisa: conceptualization, writing – review and editing. Umar Aziz: conceptualization, writing – review and editing. Shah Jahan: conceptualization, writing – review and editing.

The authors have nothing to report.

All authors have read and approved the final version of the manuscript and consent to its submission.

The authors declare no conflicts of interest.

This article is linked to Vuorinen et al. papers. To view these articles, visit https://doi.org/10.1111/ene.70148.