Table 1.
Baseline patient characteristics.
| Cohort 1 (n = 745) (training and testing) | Cohort 2 (n = 499) (external validation) | |
|---|---|---|
| Demographics | ||
| Age in years | 59 ± 17 | 59 ± 16 |
| Sex (female) | 317 (42%) | 243 (49%) |
| Race (Black) | 301 (40%) | 202 (40%) |
| Past medical history | ||
| Hypertension | 519 (69%) | 329 (66%) |
| Diabetes mellitus | 196 (26%) | 132 (26%) |
| Old myocardial infarction | 205 (27%) | 122 (24%) |
| Known CAD | 248 (33%) | 179 (36%) |
| Known heart failure | 130 (17%) | 74 (15%) |
| Prior PCI/CABG | 207 (28%) | 124 (25%) |
| Presenting chief complaint | ||
| Chest pain | 665 (89%) | 454 (91%) |
| Shortness of breathing | 250 (34%) | 234 (47%) |
| Indigestion, nausea, or vomiting | 117 (16%) | 109 (22%) |
| Dizziness or syncope | 106 (14%) | 79 (16%) |
| Palpitation | 96 (13%) | 62 (12%) |
| Other atypical symptoms | 54 (7%) | 37 (7%) |
| Baseline ECG rhythm | ||
| Normal sinus rhythm | 648 (87%) | 442 (88%) |
| Atrial fibrillation | 71 (9%) | 46 (9%) |
| Pacing | 26 (4%) | 8 (2%) |
| Right bundle branch block | 31 (4%) | 27 (5%) |
| Left bundle branch block | 19 (3%) | 16 (3%) |
| Left ventricular hypertrophy | 37 (5%) | 24 (5%) |
| Primary study outcome | ||
| Any ACS event | 114 (15.3%) | 92 (18.4%) |
| Prehospital STEMI | 31 (4.2%) | 18 (3.6%) |
| NSTE-ACS | 83 (11.1%) | 74 (14.8%) |
| Course of hospitalization | ||
| Length of stay (median [IQR]) | 2.3 [1.0–3.0] | 1.2 [0.6-2.5] |
| Stress testing with SPECT | 180 (24%) | 115 (23%) |
| Treated by primary PCI/CABG | 74 (10%) | 65 (13%) |
| 30-day cardiovascular death | 33 (4.4%) | 24 (4.8%) |