Table 1.
Demographic and QT variables stratified by mortality.
| Dead (n = 222) | Alive (n = 559) | P-value | |
|---|---|---|---|
| Age, years, mean (SD) | 74.9 (7.97) | 64.9 (9.19) | <0.001 |
| Age, 65 years and over, no. % | 202 (91.0%) | 299 (53.5%) | <0.001 |
| Men, no. % | 126 (56.8%) | 253 (45.3%) | <0.001 |
| Race, no. (%) | |||
| White | 202 (91.0%) | 512 (91.6%) | 0.976 |
| Black | 17 (7.7%) | 35 (6.3%) | |
| Other | 3 (1.4%) | 12 (2.1%) | |
| BMI, kg/m2, mean (SD) | 26.3 (4.34) | 27.4 (4.34) | <0.001 |
| Waist Circumference, cm, mean (SD) | 95.4 (12.6) | 95.0 (12.4) | <0.001 |
| Neck Circumference, mean (SD) | 37.6 (3.80) | 37.4 (3.87) | <0.001 |
| Smoking Status, no. (%) | |||
| Never | 94 (42.3%) | 282 (50.4%) | 0.256 |
| Current | 13 (5.9%) | 46 (8.2%) | |
| Former | 115 (51.8%) | 231 (41.3%) | |
| Hypertension, no. (%) | 135 (60.8%) | 216 (38.6%) | <0.001 |
| Diabetes, no. (%) | 30 (13.5%) | 28 (5.0%) | 0.594 |
| Cardiovascular Disease, no. (%) | 23 (10.4%) | 64 (11.4%) | 0.662 |
| Sleep Disordered Breathing, no. (%) | |||
| None | 45 (20.3%) | 120 (21.5%) | <0.001 |
| Mild | 49 (22.1%) | 194 (34.7%) | |
| Moderate | 61 (27.5%) | 136 (24.3%) | |
| Severe | 67 (30.2%) | 109 (19.5%) | |
| Heart Rate, mean (SD) | 65.6 (10.3) | 65.2 (8.82) | 0.191 |
| QTc interval, mean (SD)a | 422 (37.4) | 415 (28.3) | 0.002 |
| Standard deviation of the QT intervals (SDQT), mean (SD) | 11.9 (16.8) | 7.72 (8.89) | 0.014 |
| Normalized QT interval variance (QTVN), mean (SD) | 0.002 (0.006) | 0.001 (0.003) | 0.025 |
| The short-term interval beat-to-beat QT variability (STVQT), mean (SD) | 4.59 (4.95) | 3.33 (2.78) | 0.055 |
a
QTc = QT interval with Bazett’s heart rate correction.