Clinical characteristics and main time measures
| Transfer with MT | Futile transfer | P values | |
| (n=153) | (n=125) | ||
| Age, mean (SD) | 63 (13.9) | 68 (14) | 0.92 |
| Males, % | 55.6 | 62.4 | 0.25 |
| NIHSS at admission, median (IQR) | 18 (12–21) | 17 (8–20) | 0.98 |
| ≤10 | 20.90% | 30.90% | |
| 17 Nov | 21.60% | 26.80% | |
| ≥18 | 57.50% | 42.30% | |
| DWI-ASPECT score, median (IQR) | 7 (6–8) | 7 (6–8) | 0.83 |
| 0–5 | 15% | 17.60% | |
| 8 Jun | 73.10% | 63.90% | |
| 10 Sep | 11.90% | 18.50% | |
| Antecedents, % | |||
| Hypertension | 49.5 | 62.5 | 0.13 |
| Stroke or TIA | 14.2 | 14.3 | 0.99 |
| Atrial fibrillation | 24.3 | 21.8 | 0.75 |
| Diabetes mellitus | 18.2 | 17.9 | 0.97 |
| Coronary artery disease | 17.2 | 16.1 | 0.89 |
| Lower limb artery disease | 5.6 | 10.6 | 0.28 |
| Hypercholesterolemia | 19.2 | 19.6 | 0.95 |
| Etiology, % | |||
| Cardioembolism | 37.3 | 33.6 | 0.52 |
| Large artery atherosclerosis | 12.4 | 16 | 0.6 |
| Small vessel occlusion | – | – | – |
| Artery dissection | 1.3 | 1.6 | 0.86 |
| Other causes | 3.9 | 1.6 | 0.25 |
| Undetermined causes of stroke | 35.1 | 48.8 | 0.72 |
| Occlusion location, n (%) | |||
| IC ICA and carotid terminus | 18 (11.8%) | 10 (8%) | 0.69 |
| IC ICA and M1 segment of MCA | 33 (21.6%) | 19 (15.2%) | 0.78 |
| M1 segment of MCA | 76 (49.6%) | 72 (57.6%) | 0.76 |
| M2 segment of MCA | 6 (3.9%) | 4 (3.2%) | 0.22 |
| BA | 16 (10.5%) | 17 (13.6%) | 0.53 |
| Other or multiple LVO | 4 (2.6%) | 2 (1.6%) | 0.42 |
| Transport modality | |||
| Air transport | 76.30% | 77.40% | 0.63 |
| Road transport | 23.70% | 22.60% | |
| Median time in minutes (IQR) | |||
| Symptom onset to IVT start | 129 (105–162) | 152 (120–180) | 0.57 |
| Door-to-needle in PSC | 59 (38–118) | 59 (41–118) | 0.52 |
| Door-in to door-out at PSC | 87 (76–102) | 94 (77–113) | 0.54 |
| Symptom onset to CSC door-in | 271 (228–310) | 286 (253–342) | 0.92 |
| IVT start to CSC door | 123 (109–151) | 133 (110–162) | 0.59 |
| PSC door-out to CSC door-in | 95 (79–128) | 86 (75–100) | 0.86 |
| Symptom onset to recanalization | 393 (332–454) | – | – |
| Causes of futile transfer, n (% of all futile transfer) | 125/278 | ||
| Clinical improvement and/or arterial recanalization | 73 (58.4%) | ||
| Clinical worsening and/or infarct growth on MRI | 21 (16.8%) | ||
| Time out after transfer | 14 (11.2%) | ||
| Technical reason | 4 (3.2%) | ||
| Protocol deviation of transfer* | 4 (3.2%) | ||
| Neuro-interventional team or catheter room unavailability | 4 (3.2%) | ||
| Transfer due to expected worsening | 3 (2.4%) | ||
| Randomization in the medical treatment arm of the Swift–Prime study4 | 2 (1.6%) | ||
ACA, anterior cerebral artery; AIS, acute ischemic stroke; BA, basilar artery; CSC, distant comprehensive stroke center.
* Protocol deviation: DWI-ASPECTS <5 (n=3), MCA residual flow (n=1). DWI-ASPECTS, Alberta Stroke Program Early Computed TomographyCT Score on diffusion-weighted MRI; IC, intracranial; ICA, internal carotid artery; IQR, interquartile range; IVT, intravenous thrombolysis; MCA, middle cerebral artery; mRS, modified Rankin Scale; MT, mechanical thrombectomy; NIH-SS National Institute Health Stroke Scale; PSC, primary stroke center; TIA, transient ischemic attack; TICI, thrombolysis in cerebral infarction.