Table 1. Baseline Characteristics of the Patients and Features of Thrombectomy.
| Characteristic | No. (%) | |||
|---|---|---|---|---|
| Direct (n = 61) | Transfer (n = 121) | |||
| Endovascular Therapy (n = 34) | Medical Therapy (n = 27) | Endovascular Therapy (n = 58) | Medical Therapy (n = 63) | |
| Age, median (IQR), y | 71.5 (59-79) | 67 (59-81) | 69.5 (60-78) | 72 (59-80) |
| Female | 13 (38) | 10 (37) | 33 (57) | 36 (57) |
| NIHSS score, median (IQR) | 16.5 (11-21) | 15 (12-20) | 16 (10-20) | 17 (12-22) |
| Glucose level, median (IQR), mg/dL | 137.5 (113-191)a | 122 (105-159) | 118.5 (106-139)a | 126 (111-152) |
| Medical history | ||||
| Hypertension | 24 (71) | 23 (85) | 47 (81) | 14 (78) |
| Myocardial infarction | 8 (24)a | 0b | 4 (7)a | 11 (17)b |
| Atrial fibrillation | 16 (47) | 8 (30) | 18 (31) | 20 (32) |
| Diabetes | 13 (38) | 9 (33) | 15 (26) | 18 (29) |
| Dyslipidemia | 20 (59) | 12 (44) | 29 (50) | 22 (35) |
| Previous stroke | 7 (21) | 5 (19) | 6 (10) | 7 (11) |
| Stroke onset witnessed | ||||
| Yes | 8 (24) | 8 (30) | 23 (40) | 27 (43) |
| No | ||||
| Symptoms were present on awakening | 22 (65) | 13 (48) | 27 (47) | 29 (46) |
| Symptoms began during wakefulness | 4 (12) | 6 (22) | 8 (14) | 7 (11) |
| Treatment with intravenous tPA | 1 (3) | 0 | 9 (16) | 8 (13) |
| Imaging characteristic | ||||
| Qualifying imaging | ||||
| CT perfusion imaging | 26 (76) | 21 (78) | 43 (74) | 43 (68) |
| Diffusion and perfusion MRI | 8 (24) | 6 (22) | 15 (26) | 20 (32) |
| Volume of ischemic core, median (IQR), mLa | 12.2 (2.4-37.6) | 10.1 (0-30.1) | 9.4 (2.2-17.1) | 10.0 (4.1-23.9) |
| Volume of perfusion lesion (Tmax >6 s), median (IQR), mL | 122.3 (70.8-185.0) | 120.9 (80.7-156.9) | 104.2 (82.6-136.4) | 110.3 (64.2-158.5) |
| Hypoperfusion intensity ratio | 0.44 (0.23-0.58) | 0.38 (0.21-0.59) | 0.33 (0.18-0.44) | 0.35 (0.23-0.52) |
| Occlusion site on baseline CTA or MRA | ||||
| Internal carotid artery | 9 (26)b | 15 (56)c | 23 (40)b | 21 (33)c |
| Middle cerebral artery | 25 (74)b | 12 (44)c | 35 (60)b | 42 (67)c |
| ASPECTS on baseline CT, median (IQR) | 8 (7-9) | 8 (7-9) | 8 (7-9) | 8 (7-9) |
| CTA collateral score | ||||
| 0 | 0 | NA | 0 | NA |
| 1 | 1 (3) | NA | 2 (4) | NA |
| 2 | 4 (12) | NA | 9 (16) | NA |
| 3 | 7 (21) | NA | 7 (12) | NA |
| 4 | 1 (3) | NA | 3 (5) | NA |
| NA | 21 (62) | NA | 36 (63) | NA |
| Maas system10 score | ||||
| No vessel opacification (1) | 1 (3) | 0 (0) | 3 (7) | 3 (6) |
| Collaterals visible less than on contralateral side (2) | 18 (56) | 14 (56) | 25 (58) | 20 (41) |
| Collaterals visible equal to those on contralateral side (3) | 10 (31) | 7 (28) | 14 (33) | 18 (37) |
| Collaterals visible more than those on contralateral side (4) | 3 (9) | 4 (16) | 1 (2) | 7 (14) |
| Exuberant collaterals (5) | 0 | 0 | 0 | 1 (2) |
| Tan scale11 score | ||||
| Collaterals in <50% of the MCA territory | 11 (34) | 7 (28) | 11 (26) | 14 (29) |
| Collaterals in ≥50% of the MCA territory | 21 (66) | 18 (72) | 31 (74) | 35 (71) |
| Process measures, median (IQR), h:min | ||||
| Time from stroke onset to arrival to non-EVT capable hospital | NA | NA | 6:28 (4:05-8:25) | 6:26 (3:18-9:34) |
| Time from stroke onset to arrival to EVT-capable hospital | 9:00 (6:59-9:48) | 9:04 (7:39-9:39) | 9:27 (7:05-11:18) | 9:26 (6:56-12:23) |
| Time from stroke onset to qualifying imaging | 10:38 (8:20-11:44) | 9:52 (8:53-11:30) | 10:23 (7:23-11:36) | 9:58 (7:39-13:23) |
| Time from stroke onset to randomization | 11:09 (9:17-12:20) | 10:55 (10:09-12:35) | 10:48 (7:54-12:23) | 10:19 (8:19-13:38) |
| Time from qualifying imaging to femoral puncture | 1:04 (0:45-1:29) | NA | 0:53 (0:39-1:20) | NA |
| Time from femoral puncture to reperfusion | 0:38 (0:24-1:00) | NA | 0:40 (0:28-0:59) | NA |
Abbreviations: ASPECTS, Alberta Stroke Program Early Computed Tomography score; CTA, computed tomography angiography; ICA, internal carotid artery; IQR, interquartile range; MCA, middle cerebral artery; MRA, magnetic resonance angiography; NA, not applicable; NIHSS, National Institutes of Health Stroke Scale score; Tmax, bolus-shape-independent estimate of time delay for blood delivery between a main feeding artery and tissue at a given spatial location; tPA, tissue plasminogen activator (alteplase).
Volume of ischemic core indicates relative cerebral blood flow less than 30% on CT perfusion and apparent diffusion coefficient less than 620 × 10 −3 mm2/s on magnetic resonance imaging.
Variable demonstrating statistically significant (P < .05) difference within EVT group between transfer vs direct patients.
Variable demonstrating statistically significant (P < .05) difference within medical therapy only group between transfer vs direct patients.