Table 1. Clinical, Imaging, and Stroke Workflow Process Characteristics in Patients Who Received Intravenous Alteplase and Those Who Did Not, Stratified by Recanalization Statusa.
| Variable | All Patients (N = 575) | Received Intravenous Alteplase | Did Not Receive Intravenous Alteplase | ||||
|---|---|---|---|---|---|---|---|
| Successful Recanalization(n = 143) | No Successful Recanalization (n = 327) | P Value | Successful Recanalization (n = 14) | No Successful Recanalization (n = 91) | P Value | ||
| Clinical | |||||||
| Age, median (IQR), y | 72 (63-80) | 73 (64-81) | 72 (61-80) | .28 | 70 (68-76) | 72 (64-81) | .83 |
| Male sex, No. (%) | 296 (51.5) | 76 (53.2) | 161 (49.2) | .48 | 12 (85.7) | 47 (51.6) | .02 |
| Baseline NIHSS score, median (IQR) (n = 574)b | 14 (8-19) | 12 (7-18) | 15 (10-20) | <.001 | 5.5 (2-10) | 13 (6-18) | .005 |
| History, No. (%) | |||||||
| Coronary artery disease | 118 (20.5) | 26 (18.2) | 60 (18.3) | >.99 | 6 (42.9) | 26 (28.6) | .35 |
| Stroke or transient ischemic attack | 93 (16.2) | 24 (16.8) | 46 (14.1) | .48 | 2 (14.3) | 21 (23.1) | .73 |
| Hypertension | 356 (61.9) | 91 (63.6) | 200 (61.2) | .68 | 9 (64.3) | 56 (61.5) | >.99 |
| Dyslipidemia (n = 572) | 189 (33) | 51 (35.7) | 110 (33.9) | .75 | 4 (28.6) | 24 (26.4) | >.99 |
| Antiplatelet use | 201 (35) | 51 (35.7) | 116 (35.5) | >.99 | 6 (42.9) | 28 (30.8) | .37 |
| Atrial fibrillation | 177 (30.8) | 41 (28.7) | 88 (26.9) | .74 | 8 (57.1) | 40 (44) | .40 |
| Anticoagulation | 76 (13.2) | 15 (10.5) | 34 (10.4) | >.99 | 3 (21.4) | 24 (26.4) | >.99 |
| Diabetes | 86 (15) | 16 (11.2) | 59 (18) | .07 | 2 (14.3) | 9 (9.9) | .64 |
| Smoking (n = 562) | 233 (41.5) | 53 (38.4) | 133 (41.6) | .54 | 6 (42.9) | 41 (45.6) | >.99 |
| Heart rate, median (IQR), /min (n = 544) | 76 (66.5-88) | 77 (70-90) | 77.5 (67-86) | .17 | 74 (62-80) | 76 (65-90) | .32 |
| Systolic blood pressure, median (IQR), mm Hg (n = 572) | 147 (132-167) | 150 (133-170) | 148 (134-167) | .16 | 137.5 (136-152) | 140 (126-160) | .32 |
| Diastolic blood pressure, median (IQR), mm Hg (n = 572) | 81 (71-90) | 81 (71-92) | 81 (71-90) | .81 | 86 (71-93) | 80 (70-90) | .55 |
| Blood glucose, median (IQR), mg/dL (n = 574) | 115.3 (104.5-131.5) |
115.3 (104.5-131.5) |
115.3 (102.7-138.7) |
.39 | 109.9 (97.3-145.9) |
111.7 (100.9-127.9) |
.94 |
| Serum creatinine, median (IQR), mg/dL | 0.9 (0.7-1.1) | 0.9 (0.7-1.0) | 0.9 (0.7-1.1) | .84 | 1.1 (1.0-1.2) | 0.9 (0.8-1.1) | .002 |
| Hematocrit, median (IQR), % | 41 (38-44) | 41 (38-44) | 41 (37-44) | .51 | 43 (42-48) | 42 (36-44) | .02 |
| Platelet count, median (IQR), ×109/L (n = 574) | 208.5 (170-254) | 209 (169-255) | 208 (170-257) | .98 | 211 (168-243) | 207 (171-248) | .55 |
| International normalized ratio, median (IQR) (n = 573) | 1 (1-1.1) | 1 (1-1.1) | 1 (1-1.1) | .93 | 1.1 (1-1.3) | 1.1 (1-1.3) | .48 |
| Partial thromboplastin time, median (IQR), s (n = 569) | 27.9 (25-30) | 28 (26-30.5) | 27.3 (24.3-29.6) | .01 | 29.2 (28-34.7) | 27.9 (25.6-30.9) | .08 |
| Total cholesterol, median (IQR), mg/dL (n = 545) | 162.4 (135.3-193.4) |
170.1 (135.3-197.2) |
166.3 (135.3-197.2) |
.56 | 147.0 (139.2-166.3) |
154.7 (131.5-181.7) |
.51 |
| Etiology of ischemic stroke, No. (%) | |||||||
| Extracranial large artery disease | 86 (15.0) | 18 (12.6) | 56 (17.1) | .50 | 2 (14.3) | 10 (11.0) | .22 |
| Intracranial artery disease | 15 (2.6) | 3 (2.1) | 9 (2.7) | 1 (7.1) | 2 (2.2) | ||
| Cardioembolic | 309 (53.7) | 81 (56.6) | 157 (48.0) | 11 (78.6) | 60 (65.9) | ||
| Other causes | 12 (2.1) | 2 (1.4) | 8 (2.4) | 0 | 2 (2.2) | ||
| Undetermined | 153 (26.6) | 39 (27.3) | 97 (29.7) | 0 | 17 (18.7) | ||
| Imaging | |||||||
| Baseline ASPECTS on NCCT, median (IQR) (n = 540)c | 9 (7-10) | 9 (8-10) | 9 (7-9) | .10 | 9 (8-10) | 9 (7-10) | .48 |
| Site of intracranial occlusion at baseline, No. (%) | |||||||
| Internal carotid artery | 104 (18.1) | 10 (7.0) | 82 (25.1) | <.001 | 0 | 12 (13.2) | .05 |
| MCA: proximal M1 segment | 139 (24.2) | 24 (16.8) | 87 (26.6) | 1 (7.1) | 27 (29.7) | ||
| MCA: distal M1 segment | 103 (17.9) | 39 (27.3) | 45 (13.8) | 4 (28.6) | 15 (16.5) | ||
| MCA: M2 segment | 184 (32.0) | 53 (37.1) | 90 (27.5) | 7 (50.0) | 34 (37.4) | ||
| Distal (M3 MCA, ACA, PCA) | 45 (7.8) | 17 (11.9) | 23 (7.0) | 2 (14.3) | 3 (3.3) | ||
| Residual flow within intracranial thrombus, No. (%)d | |||||||
| Grade 0 | 462 (80.3) | 91 (63.6) | 286 (87.5) | <.001 | 9 (64.3) | 76 (83.5) | .13 |
| Grade 1 | 57 (9.9) | 22 (15.4) | 26 (7.9) | 2 (14.3) | 7 (7.7) | ||
| Grade 2 | 56 (9.7) | 30 (20.1) | 15 (4.6) | 3 (21.4) | 8 (8.8) | ||
| Clot burden score, No. (%)e | |||||||
| 0-4 | 149 (25.9) | 13 (9.1) | 114 (34.9) | <.001 | 1 (7.1) | 21 (23.1) | .45 |
| 5-7 | 172 (29.9) | 48 (33.6) | 90 (27.5) | 5 (35.7) | 29 (32.0) | ||
| 8-10 | 254 (44.2) | 82 (57.3) | 123 (37.6) | 8 (57.1) | 41 (45.1) | ||
| Stroke Workflow Process and Times | |||||||
| Time from onset (last known well) to baseline CT angiography, median (IQR), min | 114 (74-180) | 109 (73-170) | 107 (73-156) | .75 | 165.5 (97-312) | 180 (83-334) | .87 |
| Time from baseline CT angiography to intravenous alteplase start, median (IQR), min | 19 (11-28) | 18 (11-30) | 19 (12-28) | .64 | |||
| Endovascular therapy, No. (%) | 243 (42.3) | 19 (13.3) | 176 (53.8) | <.001 | 3 (21.4) | 45 (49.4) | .08 |
| Time from baseline CT angiography to recanalization assessment, median (IQR), min | 158 (79-268) | 245 (154-290) | 115 (70-238) | <.001 | 256 (228-302) | 177 (62-272) | .07 |
| Time from intravenous alteplase start to recanalization assessment, median (IQR), min | 132.5 (62-238) | 221 (141-273) | 92 (50-209) | <.001 | |||
Abbreviations: ACA, anterior cerebral artery; CT, computed tomography; IQR, interquartile range; MCA, middle cerebral artery; NCCT, noncontrast computed tomography; NIHSS, National Institutes of Health Stroke Scale; PCA, posterior cerebral artery.
SI conversion factors: To convert glucose to mmol/L, multiply values by 0.055; to convert creatinine to μmol/L, multiply values by 88.4; to convert cholesterol to mmol/L, multiply values by 0.0259.
Recanalization of intracranial thrombus with intravenous alteplase or not was assessed using the rAOL (revised arterial occlusive lesion) score on repeat head CTA or on first angiographic acquisition of the affected intracranial circulation. Successful recanalization was defined as an rAOL score of 2b or 3. The rAOL score is described in detail in the Methods and eTable 1 in the Supplement.
NIHSS score ranges from 0-42, with higher scores indicating greater stroke severity.
ASPECTS (Alberta Stroke Program Early Computed Tomography Score) measures extent of early ischemic change in the MCA territory on a 0-10 scale. Higher scores indicate smaller extent of early ischemic changes.
Residual flow grade is assessed on CTA source images (3-mm maximum intensity projections preferred) as follows: grade 0, no contrast permeation of thrombus; grade 1, contrast permeating diffusely through thrombus; and grade 2, tiny hairline lumen or streak of well-defined contrast within the thrombus extending either through its entire length or part of the thrombus.
Clot burden score is an ordinal score that measures extent of thrombus within the anterior circulation vessels. A score of 0 implies complete occlusion of the ipsilateral anterior circulation vessels; 10 implies no occlusion.