Optimizing Patient Selection for Interhospital Transfer and Endovascular Therapy in Acute Ischemic Stroke: Real-World Data From a Supraregional, Hub-and-Spoke Neurovascular Network in Germany

Abstract

Background: Interhospital transfer for endovascular treatment (EVT) within neurovascular networks might result in transfer of patients who will not undergo EVT (futile transfer). Limited evidence exists on factors associated with the primary patient selection for interhospital transfer from primary stroke centers (PSCs) to comprehensive stroke centers (CSCs), or EVT-workflow parameters that may render a transfer futile.Methods: A prospective, registry-based study was performed between July 1, 2017 and June 30, 2018, at a hub-and-spoke neurovascular network in southwest Germany, comprising 12 referring PSCs and one designated CSC providing round-the-clock EVT at the University Hospital Tübingen. Patients with acute ischemic stroke due to suspected large artery occlusion (LAO) were included upon emergency interhospital transfer inquiry (ITI).Results: ITI was made for 154 patients, 91 (59%) of whom were transferred to the CSC. Non-transferred patients (41%) had significantly higher premorbid modified Rankin scale scores (mRS) compared to transferred patients [median (IQR): 2 (1–3) vs. 0 (0–1), p < 0.001]. Interhospital transfer was denied due to: distal vessel occlusion (44.4%), or non-verifiable LAO (33.3%) in computed tomography angiography (CTA) upon teleconsultation by CSC neuroradiologists; limited Stroke-Unit or ventilation capacity (9.5%), or limited neuroradiological capacity at the CSC (12.7%). The CT-to-ITI interval was significantly longer in patients denied interhospital transfer [median (IQR): 43 (29–56) min] compared to transferred patients [29 (15–55), p = 0.029]. No further differences in EVT-workflow, and no differences in the 3-month mRS outcomes were noted between non-transferred and transferred patients [median (IQR): 2 (0–5) vs. 3 (1–4), p = 0.189]. After transfer to the CSC, 44 (48%) patients underwent EVT. The Alberta stroke program early CT score [ORadj (95% CI): 1.786 (1.573–2.028), p < 0.001] and the CT-to-ITI interval [0.994 (0.991–0.998), p = 0.001] were significant predictors of the likelihood of EVT performance.Conclusion: Our findings show that hub-and-spoke neurovascular network infrastructures efficiently enable access to EVT to patients with AIS due to LAO, who are primarily admitted to PSCs without on-site EVT availability. As in real-world settings optimal allocation of EVT resources is warranted, teleconsultation by experienced endovascular interventionists and prompt interhospital-transfer-inquiries are crucial to reduce the futile transfer rates and optimize patient selection for EVT within neurovascular networks.

Clinical outcomes of delayed mechanical thrombectomy: Descriptive analysis and development of a screening tool

“…Our findings support a recent study showing that MT is an effective treatment in the extended time frame [5] and NCCT can be safely used to select appropriate patients [11]. Furthermore, they support recent studies showing that hub-and-spoke stroke network infrastructures enable access to successful MT in patients with stroke living remotely [12,13]. In keeping with other hub-and-spoke stroke transfer studies, we found NIHSS score, ASPECTS and age to be important determinants of outcome [12,13].…”

Direct to angiography suite approaches for the triage of suspected acute stroke patients: a systematic review and meta-analysis

“…These processes can be further optimized if the primary stroke centers and comprehensive stroke centers are integrated in a network and use tools such as teleconsulting and teleradiology. 28 Our results support a recent expert statement, recommending repeated imaging in transfer patients only in cases of clinical deterioration or improvement, 29 as this can significantly reduce door-to-treatment times in these patients.…”

Relationship between primary stroke center volume and time to endovascular thrombectomy in acute ischemic stroke

“…We defined high PSC volume as >12 EVT referrals per year based on the distribution of our data; only 15% of PSCs had >12 annual EVT referrals. Although few previous studies have reported on EVT referral volumes, average PSC volumes in our study seem relatively high compared to those found in regions in Germany and Australia (six annual EVT referrals per PSC in our study vs. four in both Germany and Australia) [ 26 , 27 . Nonetheless, it is possible that for even higher EVT referral volumes, an association with shorter time to treatment would exist.…”