Table 1.
Comparison of Baseline Clinical and ECG Characteristics in Black and White Participants
| Characteristics | Black Participants (n=3739) | White Participants (n=10 669) | P Value |
|---|---|---|---|
| Age, mean (SD), y | 53.5 (5.8) | 54.4 (5.7) | <0.0001 |
| Women, n (%) | 2309 (61.8) | 5622 (52.7) | <0.0001 |
| Heart failure, n (%) | 257 (6.9) | 407 (3.8) | <0.0001 |
| Coronary heart disease, n (%) | 148 (4.0) | 534 (5.0) | 0.009 |
| Stroke, n (%) | 106 (2.8) | 138 (1.29) | <0.0001 |
| Body mass index, mean (SD), kg/m2 | 29.6 (6.2) | 27.0 (4.9) | <0.0001 |
| Diabetes mellitus, n (%) | 733 (19.6) | 965 (9.0) | <0.0001 |
| Hypertension, n (%) | 2077 (55.6) | 2886 (27.1) | <0.0001 |
| Antihypertensive drugs, n (%) | 1644 (44.0) | 2731 (25.6) | <0.0001 |
| Current tobacco smoker, n (%) | 1126 (30.1) | 2643 (24.8) | <0.0001 |
| Current alcohol drinker, n (%) | 1189 (31.8) | 6894 (64.6) | <0.0001 |
| Leisure physical activity score, mean (SD) | 2.1 (0.6) | 2.5 (0.5) | <0.0001 |
| Sport physical activity score, mean (SD) | 2.2 (0.7) | 2.5 (0.8) | <0.0001 |
| Work physical activity score, mean (SD) | 2.3 (1.0) | 2.1 (0.9) | <0.0001 |
| Family income <$25 000, n (%) | 2406 (64.4) | 2779 (26.0) | <0.0001 |
| Education less than high school, n (%) | 1538 (41.1) | 1813 (17.0) | <0.0001 |
| Health insurance, n (%) | 2883 (77.1) | 10 163 (95.3) | <0.0001 |
| Total cholesterol, mean (SD), mmol/L | 5.6 (1.2) | 5.6 (1.1) | 0.924 |
| HDL cholesterol, mean (SD), mg/dL | 55.2 (17.7) | 50.4 (16.7) | <0.0001 |
| Triglycerides, mean (SD), mmol/L | 1.3 (0.9) | 1.6 (1.0) | <0.0001 |
| Chronic kidney disease stage ≤1, n (%) | 2901 (77.6) | 7039 (66.0) | <0.0001 |
| Use of antiarrhythmic drugs, n (%) | 548 (14.7) | 1464 (13.7) | 0.156 |
| Heart rate, mean (SD), bpm | 66.5 (11.0) | 66.2 (9.9) | 0.132 |
| QRS duration, mean (SD), ms | 91.4 (12.6) | 92.5 (12.2) | <0.0001 |
| QTc, mean (SD), ms | 418 (21) | 416 (18) | <0.0001 |
| Cornell voltage, mean (SD), mV | 1.5 (0.6) | 1.2 (0.5) | <0.0001 |
| Peak QRS‐T angle, mean (circular SD), ° | 47.3 (36.3) | 40.6 (30.2) | <0.001 |
| Area QRS‐T angle, mean (circular SD), ° | 60.8 (29.4) | 60.4 (27.6) | <0.05 |
| Peak SVG elevation, mean (circular SD), ° | 66.4 (14.2) | 62.4 (15.5) | <0.001 |
| Area SVG elevation, mean (circular SD), ° | 71.5 (15.9) | 66.0 (17.5) | <0.001 |
| Peak SVG azimuth, mean (circular SD), ° | 6.7 (19.5) | 1.2 (21.1) | <0.001 |
| Area SVG azimuth, mean (circular SD), ° | 25.2 (21.5) | 24.6 (21.5) | <0.001 |
| SAI QRST, mean (SD), mV*ms | 157 (60) | 139 (46) | <0.0001 |
| Peak SVG magnitude, mean (SD), mV | 1.8 (0.5) | 1.5 (0.4) | <0.0001 |
| SVG magnitude, mean (SD), mV | 2.0 (0.5) | 1.6 (0.4) | <0.0001 |
Bpm indicates beats per minute; HDL, high‐density lipoprotein; SAI QRST, sum absolute QRST integral; SVG, spatial ventricular gradient; QTc, corrected QT.