Table 1. Baseline Characteristics and Process Measures.
| Baseline Characteristic | No./Total No. (%) | χ2/z Value | P Value | Propensity Score Matching | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| All | Control | EVT | No./No. (%) | χ2/z Value | P Value | |||||
| All | Control | EVT | ||||||||
| Age, median (IQR), y | 65 (57-74) | 67 (59-76) | 64 (56-73) | z = −3.057 | .002 | 67 (59-75) | 66 (59-75) | 67 (60-75) | z = −0.185 | .85 |
| ≥65 | 428/829 (51.6) | 109/182 (59.9) | 319/647 (49.3) | χ21 = 6.373 | .01 | 190/334 (56.9) | 96/167 (57.5) | 94/167 (56.3) | χ21 = 0.049 | .83 |
| Male | 612/829 (73.8) | 129/182 (70.9) | 483/647 (74.7) | χ21 = 1.046 | .31 | 233/334 (69.8) | 120/167 (71.9) | 113/167 (67.7) | χ21 = 0.695 | .40 |
| Baseline NIHSS score, median (IQR) | 27 (16-33) | 26.5 (16-33) | 27 (17-33) | z = −0.658 | .51 | 25 (14-32) | 25 (15-32) | 24 (14-32) | z = −0.469 | .64 |
| ≥27 | 417/829 (50.3) | 91/182 (50.0) | 326/647 (50.4) | χ21 = 0.008 | .93 | 154/334 (46.1) | 80/167 (47.9) | 74/167 (44.3) | χ21 = 0.434 | .51 |
| Deficit at time of treatment | ||||||||||
| Mild to moderate | 185/829 (22.3) | 45/182 (24.7) | 140/647 (21.6) | χ21 = 0.781 | .38 | 88/334 (26.3) | 44/167 (26.3) | 44/167 (26.3) | χ21 = 0.000 | >.99 |
| Severe | 644/829 (77.7) | 137/182 (75.3) | 507/647 (78.4) | 246/334 (73.7) | 123/167 (73.7) | 123/167 (73.7) | ||||
| Baseline pc-ASPECTS, median (IQR) | 8 (7-9) | 7 (6-8) | 8 (7-9) | z = −5.351 | <.001 | 7 (6-9) | 7 (6-8) | 8 (7-9) | z = −1.562 | .12 |
| ≥8 | 468/823 (56.9) | 78/180 (43.3) | 390/643 (60.7) | χ21 = 17.199 | <.001 | 163/334 (48.8) | 78/167 (46.7) | 85/167 (50.9) | χ21 = 0.587 | .44 |
| ASITN/SIR grade | ||||||||||
| 0-1 | 509/829 (61.4) | 119/182 (65.4) | 390/647 (60.3) | χ22 = 2.831 | .24 | 200/334 (59.9) | 105/167 (62.9) | 95/167 (56.9) | χ22 = 4.140 | .13 |
| 2 | 213/829 (25.7) | 38/182 (20.9) | 175/647 (27.0) | 92/334 (27.5) | 38/167 (22.8) | 54/167 (32.3) | ||||
| 3-4 | 107/829 (12.9) | 25/182 (13.7) | 82/647 (12.7) | 42/334 (12.6) | 24/167 (14.4) | 18/167 (10.8) | ||||
| PC-CS score, median (IQR) | 4 (3-6) | 4 (3-6) | 4 (3-6) | z = −1.147 | .25 | 5 (4-6) | 5 (4-6) | 5 (4-6) | z = −0.287 | .77 |
| ≥5 | 410/828 (49.5) | 89/182 (48.9) | 321/646 (49.7) | χ21 = 0.035 | .85 | 181/334 (54.2) | 87/167 (52.1) | 94/167 (56.3) | χ21 = 0.591 | .44 |
| Prodromal transient ischemic attack or minor stroke | 397/829 (47.9) | 95/182 (52.2) | 302/647 (46.7) | χ21 = 1.735 | .19 | 167/334 (50.0) | 89/167 (53.3) | 78/167 (46.7) | χ21 = 1.449 | .23 |
| Body temperature, median (IQR), °C | 36.6 (36.5-36.8) | 36.6 (36.5-36.9) | 36.6 (36.5-36.8) | z = −1.521 | .13 | 36.6 (36.5-36.8) | 36.6 (36.5-36.9) | 36.6 (36.5-36.8) | z = −0.890 | .37 |
| Serum glucose, median (IQR), mmol/L | 7.4 (6.0-9.6) | 7.3 (5.8-9.0) | 7.4 (6.1-9.7) | z = −1.271 | .20 | 7.3 (5.9-9.4) | 7.3 (5.7-9.0) | 7.3 (6.1-9.6) | z = −1.020 | .31 |
| Blood pressure on admission, median (IQR), mm Hg | ||||||||||
| Systolic | 151 (135-169) | 160 (142-174) | 150 (134-166) | z = −4.004 | <.001 | 155 (140-171) | 156 (140-171) | 152 (133-173) | z = −1.066 | .29 |
| Diastolic | 85 (78-98) | 89 (80-100) | 85 (77-97) | z = −2.446 | .01 | 87 (80-97) | 88 (80-98) | 86 (78-97) | z = −1.210 | .23 |
| Medical history | ||||||||||
| Hypertension | 585/829 (70.6) | 134/182 (73.6) | 451/647 (69.7) | χ21 = 1.051 | .31 | 249/334 (74.6) | 126/167 (75.4) | 123/167 (73.7) | χ21 = 0.142 | .71 |
| Hyperlipidemia | 283/829 (34.1) | 69/182 (37.9) | 214/647 (33.1) | χ21 = 1.478 | .22 | 118/334 (35.3) | 65/167 (38.9) | 53/167 (31.7) | χ21 = 1.887 | .17 |
| Diabetes mellitus | 189/829 (22.8) | 40/182 (22.0) | 149/647 (23.0) | χ21 = 0.089 | .77 | 77/334 (23.1) | 36/167 (21.6) | 41/167 (24.6) | χ21 = 0.422 | .52 |
| Smoking | 277/829 (33.4) | 42/182 (23.1) | 235/647 (36.3) | χ21 = 11.199 | .001 | 86/334 (25.7) | 42/167 (25.1) | 44/167 (26.3) | χ21 = 0.063 | .80 |
| Ischemic stroke | 188/829 (22.7) | 48/182 (26.4) | 140/647 (21.6) | χ21 = 1.816 | .18 | 81/334 (24.3) | 43/167 (25.7) | 38/167 (22.8) | χ21 = 0.407 | .52 |
| Coronary heart disease | 132/829 (15.9) | 27/182 (14.8) | 105/647 (16.2) | χ21 = 0.206 | .65 | 53/334 (15.9) | 26/167 (15.6) | 27/167 (16.2) | χ21 = 0.022 | .88 |
| Atrial fibrillation | 160/829 (19.3) | 24/182 (13.2) | 136/647 (21.0) | χ21 = 5.596 | .02 | 53/334 (15.9) | 22/167 (13.2) | 31/167 (18.6) | χ21 = 1.817 | .18 |
| Stroke causative mechanism | ||||||||||
| Large artery atherosclerosis | 539/829 (65.0) | 121/182 (66.5) | 418/647 (64.6) | χ23 = 17.381 | .001 | 232/334 (69.5) | 117/167 (70.7) | 115/167 (68.9) | χ23 = 2.356 | .50 |
| Cardioembolism | 205/829 (24.7) | 32/182 (17.6) | 173/647 (26.7) | 69/334 (20.7) | 31/167 (18.6) | 38/167 (22.8) | ||||
| Other | 23/829 (2.8) | 4/182 (2.2) | 19/647 (2.9) | 9/334 (2.7) | 4/167 (2.4) | 5/167 (3.0) | ||||
| Unknown | 62/829 (7.5) | 25/182 (13.7) | 37/647 (5.7) | 24/334 (7.2) | 15/167 (9.0) | 9/167 (5.4) | ||||
| Occlusion sites | ||||||||||
| Distal basilar artery | 267/829 (32.2) | 45/182 (24.7) | 222/647 (34.3) | χ23 = 39.506 | <.001 | 80/334 (24.0) | 40/167 (24.0) | 40/167 (24.0) | χ23 = 0.000 | >.99 |
| Middle basilar artery | 295/829 (35.6) | 100/182 (54.9) | 195/647 (30.1) | 188/334 (56.3) | 94/167 (56.3) | 94/167 (56.3) | ||||
| Proximal basilar artery | 121/829 (14.6) | 14/182 (7.7) | 107/647 (16.5) | 26/334 (7.8) | 13/167 (7.8) | 13/167 (7.8) | ||||
| Vertebral artery–V4 segment | 146/829 (17.6) | 23/182 (12.6) | 123/647 (19.0) | 40/334 (12.0) | 20/167 (12.0) | 20/167 (12.0) | ||||
| Treatment profiles | ||||||||||
| Intravenous thrombolysis | 166/829 (20.0) | 47/182 (25.8) | 119/647 (18.4) | χ21 = 4.899 | .03 | 73/334 (21.9) | 43/167 (25.7) | 30/167 (18.0) | χ21 = 2.963 | .09 |
| Onset to imaging diagnosis time, median (IQR), min | 204 (88-356) | 194 (87-388) | 210 (88-354) | z = −1.323 | .19 | 204 (79-358) | 185 (80-351) | 216 (72-361) | z = 0.468 | .64 |
| Onset to treatment, median (IQR), min | 245 (128.5-393.5) | 221.5 (116.25-407) | 246 (132-390) | z = −0.272 | .79 | 240.5 (117-393.25) | 219 (111-398) | 253 (125-385) | z = −0.483 | .63 |
| Onset to treatment, h | ||||||||||
| 0-3 | 303/829 (36.6) | 71/182 (39.0) | 232/647 (35.9) | χ23 = 3.554 | .31 | 129/334 (38.6) | 67/167 (40.1) | 62/167 (37.1) | χ23 = 1.450 | .69 |
| 3-6 | 287/829 (34.6) | 56/182 (30.8) | 231/647 (35.7) | 107/334 (32.0) | 51/167 (30.5) | 56/167 (33.5) | ||||
| 6-9 | 124/829 (15.0) | 24/182 (13.2) | 100/647 (15.5) | 47/334 (14.1) | 21/167 (12.6) | 26/167 (15.6) | ||||
| >9 | 115/829 (13.9) | 31/182 (17.0) | 84/647 (13.0) | 51/334 (15.3) | 28/167 (16.8) | 23/167 (13.8) | ||||
| Onset to groin puncture, median (IQR), min | NA | NA | 328 (220-493) | NA | NA | NA | NA | 350 (219-531) | NA | NA |
| Onset to revascularization, median (IQR), min | NA | NA | 441 (328-627) | NA | NA | NA | NA | 470 (326-680) | NA | NA |
| Groin puncture to revascularization, median (IQR), min | NA | NA | 105 (71-151) | NA | NA | NA | NA | 112 (75-169) | NA | NA |
| General anesthesia | NA | NA | 257/639 (40.2) | NA | NA | NA | NA | 64/164 (39.0) | NA | NA |
| Type of endovascular treatment | ||||||||||
| Stent retriever thrombectomy | NA | NA | 482/643 (75.0) | NA | NA | NA | NA | 120/167 (71.9) | NA | NA |
| Aspiration | NA | NA | 20/643 (3.1) | NA | NA | NA | NA | 4/167 (2.4) | NA | NA |
| Balloon angioplasty and/or stenting | NA | NA | 66/643 (10.2) | NA | NA | NA | NA | 22/167 (13.2) | NA | NA |
| Intra-arterial medication and/or mechanical fragmentation | NA | NA | 75/643 (11.7) | NA | NA | NA | NA | 21/167 (12.6) | NA | NA |
| Combination | NA | NA | 422/643 (65.6) | NA | NA | NA | NA | 116/167 (69.5) | NA | NA |
Abbreviations: ASITN/SIR, American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology System; EVT, endovascular treatment; IQR, interquartile range; NA, not applicable; NIHSS, National Institutes of Health Stroke Scale; pc-ASPECTS, Posterior Circulation-Alberta Stroke Program Early CT Score; PC-CS, Posterior Circulation Collateral Score.
SI conversion factor: To convert glucose to mmol/L, multiply by 0.0555.