Table 1. Baseline Characteristics of the Study Populationa.
| Characteristics | Use of vitamin K antagonists (n = 3087)b | No use of vitamin K antagonists (n = 29 628) |
|---|---|---|
| Age, median (IQR), y | 78 (69-85) | 71 (60-81) |
| Sex, No. (%) | ||
| Female | 1655 (53.6) | 14 937 (50.4) |
| Male | 1432 (46.4) | 14 691 (49.6) |
| Race and ethnicity, No. (%)c | ||
| Asian | 87 (2.8) | 934 (3.2) |
| Non-Hispanic Black | 372 (12.1) | 4496 (15.2) |
| Hispanic | 194 (6.3) | 2111 (7.1) |
| Non-Hispanic White | 2249 (72.9) | 20 188 (68.1) |
| Otherd | 185 (6.0) | 1899 (6.4) |
| Health insurance status, No. (%)e | ||
| Medicare | 1602 (52.8) | 12 494 (44.1) |
| Private | 1112 (36.6) | 11 481 (40.5) |
| Medicaid | 248 (8.2) | 2892 (10.2) |
| Self-pay/no insurance | 66 (2.2) | 1372 (4.8) |
| Not documented | 8 (0.3) | 118 (0.4) |
| Admission year, No. (%) | ||
| 2015 | 119 (3.9) | 976 (3.3) |
| 2016 | 582 (18.9) | 4790 (16.2) |
| 2017 | 755 (24.5) | 6363 (21.5) |
| 2018 | 783 (25.4) | 7625 (25.7) |
| 2019 | 763 (24.7) | 8711 (29.4) |
| 2020 | 85 (2.8) | 1163 (3.9) |
| Medical history, No. (%) | ||
| Atrial fibrillation/flutter | 2530 (82.0) | 7561 (25.5) |
| Hypertension | 2404 (77.9) | 20 696 (69.9) |
| Dyslipidemia | 1579 (51.1) | 12 418 (41.9) |
| Coronary artery disease/prior myocardial infarction | 1002 (32.5) | 6566 (22.2) |
| Diabetes | 860 (27.9) | 7212 (24.3) |
| Heart failure | 809 (26.2) | 3350 (11.3) |
| Prior stroke | 809 (26.2) | 4841 (16.3) |
| Prosthetic heart valve | 347 (11.2) | 358 (1.2) |
| Chronic kidney disease | 316 (10.2) | 1998 (6.7) |
| Smoking | 274 (8.9) | 5176 (17.5) |
| Prior transient ischemic attack | 226 (7.3) | 1406 (4.7) |
| Peripheral vascular disease | 177 (5.7) | 936 (3.2) |
| Carotid stenosis | 94 (3.0) | 762 (2.6) |
| Medications prior to admission, No. (%) | ||
| Any antiplatelet medication | 867 (28.1) | 11 701 (39.5) |
| Single antiplatelet medication | 815 (26.4) | 10 072 (34.0) |
| Dual antiplatelet medication | 49 (1.6) | 1601 (5.4) |
| Antihypertensive agent | 2324 (84.5) | 15 562 (59.0) |
| Lipid-lowering agent | 1715 (55.6) | 11 295 (38.1) |
| Oral hypoglycemic agent | 571 (22.4) | 4238 (16.9) |
| Key clinical characteristics | ||
| Body mass index, median (IQR)f | 27.4 (23.7-32.0) | 27.7 (24.2-32.3) |
| Systolic blood pressure, median (IQR), mm Hg | 148 (130-167) | 148 (131-168) |
| Diastolic blood pressure, median (IQR), mm Hg | 82 (71-94) | 82 (71-95) |
| Heart rate, median (IQR), /min | 82 (70-96) | 80 (70-93) |
| Serum glucose, median (IQR), mg/dL | 123 (105-151) | 123 (105-153) |
| International normalized ratio | ||
| Median (IQR) | 1.5 (1.2-1.9) | 1.1 (1.0-1.1) |
| >1.7, No./total (%) | 830/2415 (34.4) | 257/21 456 (1.2) |
| Serum creatinine, median (IQR), mg/dL | 1.0 (0.8-1.2) | 1.0 (0.8-1.2) |
| Ambulatory status, No. (%) | ||
| Prior to admission | ||
| Able to ambulate independently | 2186 (93.1) | 21 440 (95.2) |
| With assistance from another person | 114 (4.9) | 713 (3.2) |
| Unable to ambulate | 47 (2.0) | 379 (1.7) |
| At admission | ||
| Able to ambulate independently | 116 (7.0) | 1531 (9.9) |
| With assistance from person | 277 (16.7) | 2814 (18.1) |
| Unable to ambulate | 1269 (76.4) | 11 187 (72.0) |
| NIHSS score, median (IQR)g | 18 (14-23) | 17 (13-22) |
| Key treatment characteristics | ||
| Arrival via emergency medical services, No. (%) | 1761 (57.0) | 17 122 (57.8) |
| Off-hours arrival, No. (%) | 1745 (56.5) | 16 513 (55.7) |
| Onset-to-EVT time, median (IQR), min | 209 (154-265) | 205 (152-268) |
| Door-to-EVT time, median (IQR), min | 77 (46-112) | 77 (46-111) |
| Intravenous tPA, No. (%) | 1313 (42.5) | 23 290 (78.6) |
| Onset-to-needle time, median (IQR), min | 111 (85-151) | 104 (77-146) |
| Door-to-needle time, median (IQR), min | 48 (37-61) | 38 (28-50) |
| Onset-to-arrival time, median (IQR), min | 120 (54-193) | 115 (53-193) |
| Large vessel occlusion, No. (%) | 2038 (94.7) | 20 672 (93.8) |
| Site of occlusion, No. (%) | ||
| Middle cerebral artery | 1762 (86.5) | 17 508 (84.7) |
| Internal carotid artery | 357 (17.5) | 3936 (19.0) |
| Other cerebral artery branch | 73 (3.6) | 760 (3.7) |
| Basilar artery | 56 (2.7) | 812 (3.9) |
| Vertebral artery | 10 (0.5) | 248 (1.2) |
Abbreviations: EVT, endovascular thrombectomy; tPA, tissue plasminogen activator.
Hospital-level characteristics of the study population are available in eTable 1 in Supplement 1.
Vitamin K antagonist exposure was defined as chart documentation that a dose was ingested within the preceding 7 days.
Race and ethnicity were ascertained from various sources including self-designation by administrative personnel during the registration process or on nursing intake forms.
Other includes American Indian or Alaska Native, Native Hawaiian or Pacific Islander, multiracial, and any other non-Black or non-White racial categories.
When patients were eligible for both Medicaid and Medicare, they were assigned to Medicaid for the purposes of this analysis.
Calculated as weight in kilograms divided by height in meters squared.
The National Institutes of Health Stroke Scale (NIHSS) is a measure of stroke severity ranging from 0 to 42. It is scored by clinical personnel during the acute stroke assessment process. Higher scores indicate more severe stroke symptoms.