Baseline characteristics and stress test results
| Demographic data | All patients (n=57 085) | Age <40 (n=7896) | Age 40–49.9 (n=15 401) | Age 50–59.9 (n=17 145) | Age 60–69.9 (n=10 288) | Age ≥70 (n=6355) | p Value |
|---|---|---|---|---|---|---|---|
| Age (years) | 53±13 | 34±5 | 45±3 | 55±3 | 65±3 | 75±4 | <0.001 |
| Female | 49% | 43% | 47% | 50% | 51% | 52% | <0.001 |
| Race | |||||||
| White | 64% | 56% | 61% | 65% | 68% | 71% | <0.001 |
| Black | 29% | 34% | 31% | 28% | 26% | 25% | <0.001 |
| Other | 7% | 10% | 8% | 7% | 6% | 4% | <0.001 |
| Haemodynamic data | |||||||
| Resting heart rate (bpm) | 73±12 | 74±13 | 74±12 | 73±12 | 72±12 | 71±12 | <0.001 |
| Resting SBP (mm Hg) | 131±19 | 123±16 | 126±17 | 131±18 | 137±19 | 142±19 | <0.001 |
| Resting DBP (mm Hg) | 81±10 | 79±11 | 81±11 | 82±10 | 82±10 | 80±10 | <0.001 |
| ppMHR achieved | 91% | 91% | 91% | 91% | 90% | 90% | <0.001 |
| Medical history | |||||||
| Hx hypertension | 62% | 36% | 51% | 66% | 76% | 83% | <0.001 |
| Hypertension medications | 43% | 20% | 32% | 46% | 58% | 65% | <0.001 |
| Hx hyperlipidaemia | 43% | 23% | 36% | 49% | 54% | 51% | <0.001 |
| Hx smoking | 41% | 34% | 43% | 45% | 42% | 36% | <0.001 |
| Hx diabetes | 18% | 9% | 13% | 19% | 25% | 26% | <0.001 |
| Family history of CAD | 51% | 51% | 56% | 54% | 48% | 39% | <0.001 |
| Hx obesity | 23% | 22% | 24% | 27% | 22% | 15% | <0.001 |
| COPD medications | 9% | 8% | 9% | 9% | 9% | 8% | 0.10 |
| Indication for stress testing | |||||||
| Chest pain | 62% | 69% | 67% | 60% | 57% | 55% | <0.001 |
| Shortness of breath | 9% | 5% | 8% | 9% | 11% | 12% | <0.001 |
| Preoperative | 2% | 1% | 1% | 2% | 3% | 5% | <0.001 |
| Other | 27% | 25% | 24% | 29% | 29% | 28% | <0.001 |
| Stress test results | |||||||
| Mean METS achieved | 9.2±3 | 11.1±3 | 10.2±3 | 9.3±3 | 7.9±3 | 6.3±2 | <0.001 |
| METS categories: | |||||||
| <6 METS | 13% | 3% | 5% | 9% | 20% | 44% | <0.001 |
| 6–9 METS | 27% | 13% | 19% | 28% | 40% | 39% | <0.001 |
| 10–11 METS | 37% | 37% | 43% | 42% | 32% | 15% | <0.001 |
| ≥12 METS | 23% | 48% | 33% | 21% | 8% | 1% | <0.001 |
Baseline characteristics and stress test results in the total cohort and by age groups. p Value shown for variance across age groups.
bpm, beats/min; CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; DBP, diastolic blood pressure; Hx, history; METS, metabolic equivalents; ppMHR, per cent predicted maximal heart rate (by 220–age); SBP, systolic blood pressure.