Table 1.
Baseline Characteristics of Patients Stratified by Troponin Concentration
| Overall (N = 250) | <5 ng/L (n = 83) | 5 ng/L to 99th Percentile (n = 167) | P Value | |
|---|---|---|---|---|
| Men | 172 (68.8) | 51 (61.4) | 121 (72.5) | 0.104 |
| Age, y | 61.4 ± 12.2 | 56.8 ± 11.2 | 63.7 ± 12.0 | <0.001 |
| Presenting symptom | 0.089 | |||
| Chest pain | 219 (87.6) | 76 (91.6) | 143 (85.6) | |
| Dyspnea | 5 (2.0) | 0 (0.0) | 5 (3.0) | |
| Palpitations | 19 (7.6) | 3 (3.6) | 16 (9.6) | |
| Other | 7 (2.8) | 4 (4.8) | 3 (1.8) | |
| Anginal symptoms | 106 (42.4) | 30 (36.1) | 76 (45.5) | 0.202 |
| Typical angina | 32 (12.8) | 6 (7.2) | 26 (15.6) | 0.097 |
| Atypical angina | 74 (29.6) | 24 (28.9) | 50 (29.9) | 0.984 |
| Cardiovascular risk factors | ||||
| BMI, kg/m2 | 29.5 ± 6.0 | 29.8 ± 6.4 | 29.3 ± 5.8 | 0.579 |
| Current or previous cigarette smoker | 136 (54.4) | 47 (56.6) | 89 (53.3) | 0.716 |
| Hypertension | 109 (43.6) | 30 (36.1) | 79 (47.3) | 0.123 |
| Diabetes mellitus | 35 (14.0) | 5 (6.0) | 30 (18.0) | 0.018 |
| Hyperlipidemia | 53 (21.3) | 20 (24.1) | 33 (19.9) | 0.547 |
| Family history of CAD | 92 (36.8) | 28 (33.7) | 64 (38.3) | 0.569 |
| Medical history | ||||
| Angina | 45 (18.0) | 11 (13.3) | 34 (20.4) | 0.229 |
| Myocardial infarction | 52 (20.8) | 12 (14.5) | 40 (24.0) | 0.115 |
| Stroke | 15 (6.0) | 2 (2.4) | 13 (7.8) | 0.161 |
| Peripheral vascular disease | 8 (3.2) | 2 (2.4) | 6 (3.6) | 0.905 |
| Atrial fibrillation | 19 (7.6) | 4 (4.8) | 15 (9.0) | 0.36 |
| Chronic kidney disease | 22 (8.8) | 3 (3.6) | 19 (11.4) | 0.071 |
| Previous revascularization | ||||
| PCI | 53 (21.2) | 13 (15.7) | 40 (24.0) | 0.178 |
| CABG | 12 (4.8) | 2 (2.4) | 10 (6.0) | 0.351 |
| Medications at presentation | ||||
| Aspirin | 61 (24.4) | 14 (16.9) | 47 (28.1) | 0.072 |
| P2Y12 inhibitor | 19 (7.6) | 4 (4.8) | 15 (9.0) | 0.36 |
| Statin | 105 (42.0) | 24 (28.9) | 81 (48.5) | 0.005 |
| ACEi or ARB | 91 (36.4) | 24 (28.9) | 67 (40.1) | 0.111 |
| Beta-blocker | 69 (27.6) | 21 (25.3) | 48 (28.7) | 0.672 |
| Oral anticoagulant | 26 (10.4) | 5 (6.0) | 21 (12.6) | 0.168 |
| Physiology and investigations | ||||
| Myocardial ischemia on ECG | 9 (3.6) | 1 (1.2) | 8 (4.8) | 0.283 |
| Heart rate, beats/min | 76 ± 18 | 77 ± 17 | 76 ± 18 | 0.89 |
| Systolic blood pressure, mm Hg | 150 ± 26 | 149 ± 24 | 151 ± 27 | 0.58 |
| Hemoglobin, g/L | 144 ± 14 | 146 ± 13 | 143 ± 15 | 0.197 |
| eGFR, mL/min/1.73 m2 | 84 ± 17 | 89 ± 13 | 82 ± 18 | 0.001 |
| Total cholesterol, mmol/L | 4.9 ± 1.2 | 5.0 ± 1.1 | 4.8 ± 1.2 | 0.151 |
| LDL cholesterol, mmol/L | 3.0 ± 1.1 | 3.2 ± 1.0 | 3.0 ± 1.2 | 0.106 |
| Peak troponin I concentration, ng/L | 6.0 (3.0-10.0) | 2.0 (1.0-3.0) | 8.0 (6.0-12.0) | <0.001 |
| TIMI risk score | 1.6 (1.3) | 1.2 (1.1) | 1.8 (1.3) | <0.001 |
| GRACE risk score | 92.5 (25.2) | 86.8 (24.6) | 96.4 (25.0) | 0.008 |
| Time intervals | ||||
| Symptom onset to first troponin test, h | 9 (3-31) | 8 (3-24) | 9 (4-45) | 0.099 |
| First to second troponin test, h | 3 (2-3) | 3 (3-3) | 3 (2-3) | 0.737 |
| Presentation to outpatient CCTA, d | 22 (15-30) | 17 (8-25) | 24 (19-31) | <0.001 |
Values are n (%), mean ± SD, or median (interquartile range).
ACEi = angiotensin-converting enzyme inhibitor; ARB = angiotensin receptor blocker; BMI = body mass index; CABG = coronary artery bypass grafting; CAD = coronary artery disease; CCTA = coronary computed tomography angiography; ECG = electrocardiogram; eGFR = estimated glomerular filtration rate; LDL = low-density lipoprotein; PCI = percutaneous coronary intervention; TIMI = Thrombolysis In Myocardial Infarction.