Table 1.
Baseline Characteristics of participants stratified by electrocardiographic risk factors
| Characteristic | Full cohort | Holter cohort | |||||||
|---|---|---|---|---|---|---|---|---|---|
|
|
|
||||||||
| LAFB status (n = 4,696) | P value† | QTC status (n = 4,696)* | P value† | APC status (n = 1,234) | P value† | ||||
|
|
|
|
|||||||
| No LAFB (n = 4,579) | LAFB (n=117) | No Prolonged QTC (n=4,557) | Prolonged QTC (n=139) | ≤ Median Percent APCs (n=634) | > Median Percent APCs (n=600) | ||||
| Median age (years) (IQR) | 71 (68–76) | 73 (69–79) | 0.001 | 71 (68–76) | 73 (69–77) | 0.022 | 70 (67–73) | 72 (69–76) | <0.001 |
| Men | 1,829 (40%) | 87 (74%) | <0.001 | 1,845 (40%) | 71 (51%) | 0.012 | 257 (41%) | 293 (49%) | 0.003 |
| White | 3,855 (84%) | 100 (85%) | 0.71 | 3,843 (84%) | 112 (81%) | 0.23 | 603 (95%) | 572 (95%) | 0.85 |
| Mean body mass index (kg/m2) | 27 ± 4.7 | 27 ± 5.0 | 0.78 | 27 ± 4.8 | 28 ± 4.6 | 0.016 | 27 ± 4.2 | 26 ± 4 | <0.001 |
| Hypertension | 1,933 (42%) | 37 (32%) | 0.021 | 1,899 (42%) | 71 (51%) | 0.028 | 280 (44%) | 220 (37%) | 0.007 |
| Diabetes mellitus | 655 (14%) | 29 (25%) | 0.002 | 660 (15%) | 24 (17%) | 0.39 | 100 (16%) | 78 (13%) | 0.17 |
| Heart failure | 116 (2.5%) | 6 (5.1%) | 0.08 | 110 (2.4%) | 12 (8.6%) | <0.001 | 14 (2.2%) | 17 (2.8%) | 0.48 |
| Coronary disease | 757 (17%) | 25 (21%) | 0.17 | 747 (16%) | 35 (25%) | 0.006 | 117 (18%) | 122 (20%) | 0.40 |
| Myocardial infarction | 340 (7.4%) | 17 (14.5%) | 0.004 | 341 (7.5%) | 16 (12%) | 0.078 | 54 (8.5%) | 74 (12%) | 0.028 |
| Incident atrial fibrillation | 1,211 (26%) | 39 (33%) | 0.10 | 1,199 (26%) | 51 (37%) | 0.006 | 114 (18%) | 221 (37%) | <0.001 |
| Left anterior fascicular block | - | - | 113 (2.5%) | 4 (2.9%) | 0.77 | 5 (.79%) | 21 (3.5%) | 0.001 | |
| Prolonged QTC | 135 (3%) | 4 (3%) | 0.77 | - | - | 21 (3.8%)‡ | 36 (7.1%) | 0.016 | |
| Median atrial premature complex count, beats/h§ (IQR) | 2.5 (0.8–9.4) | 5.3 (3.0–15) | 0.018 | 2.4 (.75–8.4) | 3.9 (1.8–12) | 0.007 | - | - | |
APC = atrial premature complex; IQR = interquartile range; LAFB = left anterior fascicular block
*
QT corrected by Framingham formula
†
For the comparison of the indicated characteristic in participants with and without the specified ECG marker
‡
QT corrected by Hodge formula. Below or equal to the median of percent APCs (n=554), Above the median of percent APCs (n=505)
§
Restricted to patients with Holter monitoring