Table 1. Baseline Characteristics of Study Cohort.
| Characteristics | No. (%) | |
|---|---|---|
| Unique arteries (N=4230) | Unique patients (N=3737) | |
| Men | 2428 (57.4) | 2171 (58.1) |
| Women | 1802 (43.6) | 1566 (41.9) |
| Age, mean (SD), y | 73.8 (9.5) | 73.8 (9.5) |
| Median (IQR), y | 74 (68-81) | 74 (68-81) |
| Race and ethnicitya | ||
| Hispanic/Latinx | 406 (9.6) | 360 (9.6) |
| Non-Hispanic/Latinx Asianb | 246 (5.8) | 214 (5.7) |
| Non-Hispanic/Latinx Black | 178 (4.2) | 162 (4.3) |
| Non-Hispanic/Latinx White | 3099 (73.3) | 2727 (73.0) |
| Otherc | 297 (7.0) | 270 (7.2) |
| Unknown | 4 (0.1) | 4 (0.1) |
| Systolic blood pressure, mean (SD), mm Hgd | 130.8 (19.1) | 130.8 (19.0) |
| Median (IQR), mm Hg | 130 (120-140) | 130 (120-140) |
| Diastolic blood pressure, mean (SD), mm Hgd | 68.2 (11.2) | 68.3 (11.1) |
| Median (IQR), mm Hg | 68 (60-75.7) | 68 (60-76) |
| Blood pressure <140/90 mm Hgd | 3132 (74.0) | 2767 (74.0) |
| Creatinine, mean (SD), mg/dLd | 1.2 (0.9) | 1.2 (0.9) |
| Median (IQR), mg/dL | 1 (0.9-1.3) | 1 (0.9-1.3) |
| High-density lipoprotein, mean (SD), mg/dLd | 46.4 (12.8) | 46.4 (12.8) |
| Median (IQR), mg/dL | 44 (38-52) | 44 (38-52) |
| Low-density lipoprotein, mean (SD), mg/dLd | 93.5 (33.4) | 93.3 (33.3) |
| Median (IQR), mg/dL | 87 (72-109) | 87 (72-108) |
| Hematocrit, mean (SD), %d | 38.5 (4.9) | 38.6 (4.9) |
| Median (IQR), % | 39 (35.4-41.6) | 39.1 (35.5-41.8) |
| Triglyceride, mean (SD), mg/dLd | 147.8 (91.7) | 148.1 (92.0) |
| Median (IQR), mg/dL | 126 (100-168) | 126 (100-168) |
| High-grade carotid stenosis | 473 (11.2) | 434 (11.6) |
| Contralateral disease | ||
| Normale | 1870 (44.2) | 1870 (50.0) |
| Moderate | 1185 (28.0) | 1185 (31.7) |
| Severef | 1002 (23.7) | 509 (13.6) |
| Occluded | 173 (4.1) | 173 (4.6) |
| Remote history of strokeg | 81 (1.9) | 72 (1.9) |
| Coronary artery disease | 186 (4.4) | 161 (4.3) |
| Diabetes | 909 (21.5) | 804 (21.5) |
| Chronic obstructive pulmonary disease | 39 (0.9) | 34 (0.9) |
| Peripheral arterial disease | 208 (4.9) | 181 (4.8) |
| Atrial fibrillation | 93 (2.2) | 81 (2.2) |
| Hypertension | 697 (16.5) | 606 (16.2) |
| COPS2, mean (SD)h | 37.4 (33.9) | 37.2 (33.8) |
| Median (IQR) | 27 (10-50) | 27 (10-50) |
| Body mass index, mean (SD)i | 27.8 (5.5) | 27.8 (5.4) |
| Median (IQR) | 27.1 (24.1-30.6) | 27.1 (24.2-30.5) |
| Smoking history, No./total (%) | ||
| Never | 1103/3758 (29.4) | 988/3319 (29.8) |
| Current | 516/3758 (13.7) | 455/3319 (13.7) |
| Former | 2139/3758 (56.9) | 1876/3319 (56.5) |
Abbreviation: COPS2, comorbidity point score, version 2.
SI conversion factors: To convert creatinine from mg/dL to μmol/L, multiply by 88.4; high-density lipoprotein and low-density lipoprotein from mg/dL to mmol/L, multiply by 0.0259; and triglycerides from mg/dL to mmol/L, multiply by 0.0113.
Race and ethnicity data were self-reported and based on fixed categories.
Included individuals who identified as Pacific Islander and Native Hawaiian.
Included individuals who identified as Non-Hispanic/Latinx American Indian, Alaska Native, or more than 1 race.
Missing data replaced with median of study participants with data by sex: blood pressure = 93, creatinine = 155, high-density lipoprotein = 538, low-density lipoprotein = 465, hematocrit = 466, triglycerides = 701, and body mass index = 127.
Includes 11 carotid arteries with unknown stenosis.
Includes 493 patients with bilateral asymptomatic severe carotid arteries and 16 patients with a unilateral asymptomatic severe carotid artery with a symptomatic contralateral severe stenosis at baseline (excluded from the study cohort).
Defined as any stroke occurring more than 6 months prior to the index study found in the electronic health record.
COPS2 is a validated comorbidity index used as a predictor of 30-day mortality (score range, 0-700 with increasing risk of death as score increases). Scores between 41 and 60 predict 30-day mortality of less than 4%.
Calculated as weight in kilograms divided by height in meters squared.