Background
Methods
Study setting and participants
Data collection and definitions
Statistical analysis
Results
Cohort analysis
Derivation (n = 494) | Internal validation (n = 123) | P1-value | External validation (n = 204) | P2-value | |
---|---|---|---|---|---|
Age < 65 years | 256 (51.8) | 68 (55.3) | 0.491 | 130 (63.7) | 0.004 |
Male, n (%) | 400 (81.0) | 93 (75.6) | 0.184 | 166 (81.4) | 0.902 |
BMI, mean ± SD | 23.7 mea | 23.9 mea | 0.509 | 24.99mea | <0.001 |
Diabetes mellitus, n (%) | 162 (32.8) | 34 (27.6) | 0.272 | 65 (31.9) | 0.811 |
Hypertension, n (%) | 256 (51.8) | 69 (56.1) | 0.395 | 101 (49.5) | 0.578 |
Chronic renal failure, n (%) | 23 (4.7) | 7 (5.7) | 0.633 | 6 (2.9) | 0.302 |
Hypercholesterolemia, n (%) | 68 (13.8) | 14 (11.4) | 0.486 | 38 (18.6) | 0.104 |
Current smoking, n (%) | 226 (45.8) | 49 (39.8) | 0.238 | 116 (56.9) | 0.008 |
Previous event, n (%) | |||||
Stroke | 21 (4.3) | 9 (7.3) | 0.157 | 7 (3.4) | 0.616 |
Variant angina | 7 (1.4) | 1 (0.8) | 1.000 | 2 (1.0) | 1.000 |
Unstable angina | 30 (6.1) | 7 (5.7) | 0.873 | 7 (3.4) | 0.157 |
Myocardial infarction | 45 (9.1) | 8 (6.5) | 0.356 | 6 (2.9) | 0.004 |
CAD | 82 (16.6) | 13 (10.6) | 0.097 | 16 (7.8) | 0.002 |
Heart failure | 16 (3.2) | 0 | 0.052 | 3 (1.5) | 0.305 |
Previous PCI | 73 (14.8) | 15 (12.2) | 0.464 | 16 (7.8) | 0.012 |
Previous CABG | 11 (2.2) | 1 (0.8) | 0.476 | 1 (0.5) | 0.196 |
Family history of CAD, n (%) | 31 (6.3) | 5 (4.1) | 0.518 | 16 (7.8) | 0.452 |
Chest pain, n (%) | |||||
Typical | 350 (70.9) | 84 (68.3) | 0.850 | 151 (74.0) | 0.175 |
Atypical | 57 (11.5) | 15 (12.2) | 14 (6.9) | ||
No chest pain | 87 (17.6) | 24 (19.5) | 39 (19.1) | ||
Other symptom, n (%) | 215 (43.5) | 48 (39.0) | 0.367 | 65 (31.9) | 0.004 |
Radiating pain, n (%) | 139 (28.1) | 27 (22.0) | 0.166 | 59 (28.9) | 0.834 |
Symptom onset to arrival, n (%) | |||||
≤ 6 h | 383 (77.5) | 79 (64.2) | 0.003 | 169 (82.8) | 0.064 |
6-24 h | 63 (12.8) | 30 (24.4) | 26 (12.7) | ||
> 24 h | 48 (9.7) | 14 (11.4) | 9 (4.4) | ||
Ambulance arrival, n (%) | 227 (46.0) | 40 (32.5) | 0.007 | 111 (54.4) | 0.042 |
Hemodynamic instability, n (%) | 88 (17.8) | 20 (16.3) | 0.685 | 35 (17.2) | 0.836 |
Positive baseline biomarker, n (%) | 199 (40.3) | 58 (47.2) | 0.167 | 63 (30.9) | 0.020 |
Location of STE, n (%) | |||||
Anterior | 209 (42.3) | 57 (46.3) | 0.253 | 82 (40.2) | 0.474 |
Inferior | 190 (38.5) | 40 (32.5) | 75 (36.8) | ||
Posterolateral | 19 (3.8) | 9 (7.3) | 6 (2.9) | ||
Diffuse | 76 (15.4) | 17 (13.8) | 41 (20.1) | ||
Height of maximal STE (mm) | 3.1±2.0 | 3.2 ± 2.1 | 0.581 | 3.5 ± 2.1 | 0.049 |
Number of leads with STE | 3.2 ± 1.2 | 3.1 ± 1.1 | 0.505 | 3.5 ± 1.3 | 0.007 |
No reciprocal change, n (%) | 252 (51.0) | 62 (50.4) | 0.904 | 126 (61.8) | 0.010 |
Concave morphology of STE, n (%) | 243 (49.2) | 51 (41.5) | 0.125 | 94 (46.1) | 0.454 |
Q wave, n (%) | 21 (4.3) | 4 (3.3) | 0.800 | 1 (0.5) | 0.007 |
LVH, n (%) | 70 (14.2) | 14 (11.4) | 0.420 | 25 (12.3) | 0.502 |
False-positive STEMI, n (%) | 90 (18.2) | 22 (17.9) | 0.932 | 22 (10.8) | 0.015 |
Model development
STEMI (n = 404) | False-positive STEMI (n = 90) | OR (95% CI) |
P-value | |
---|---|---|---|---|
Age < 65 years | 191 (47.3) | 65 (72.2) | 2.90 (1.76–4.79) | <0.001 |
Male, n (%) | 320 (79.2) | 80 (88.9) | 2.10 (1.04–4.23) | 0.038 |
BMI, mean ± SD | 23.8 ± 3.6 | 23.1 ± 3.5 | 0.95 (0.89–1.01) | 0.121 |
Diabetes mellitus, n (%) | 142 (35.1) | 20 (22.2) | 0.53 (0.31–0.90) | 0.020 |
Hypertension, n (%) | 220 (54.5) | 36 (40.0) | 0.56 (0.35–0.89) | 0.014 |
Chronic renal failure, n (%) | 17 (4.2) | 6 (6.7) | 1.63 (0.62–4.25) | 0.321 |
Hypercholesterolemia, n (%) | 63 (15.6) | 5 (5.6) | 0.32 (0.12–0.82) | 0.017 |
Current smoking, n (%) | 193 (47.8) | 33 (36.7) | 0.63 (0.40–1.01) | 0.057 |
Previous event, n (%) | ||||
Stroke | 20 (5.0) | 1 (1.1) | 0.22 (0.03–1.63) | 0.137 |
Variant angina | 2 (0.5) | 5 (5.6) | 11.82 (2.26–61.93) | 0.004 |
Unstable angina | 25 (6.2) | 5 (5.6) | 0.89 (0.33–2.40) | 0.820 |
Myocardial infarction | 37 (9.2) | 8 (8.9) | 0.97 (0.44–2.16) | 0.937 |
CAD | 68 (16.8) | 14 (15.6) | 0.91 (0.49–1.70) | 0.769 |
Heart failure | 13 (3.2) | 3 (3.3) | 1.04 (0.29–3.72) | 0.955 |
Previous PCI | 60 (14.9) | 13 (14.4) | 0.97 (0.51–1.85) | 0.922 |
Previous CABG | 9 (2.2) | 2 (2.2) | 1.00 (0.21–4.70) | 0.998 |
Family history of CAD, n (%) | 29 (7.2) | 2 (2.2) | 0.29 (0.07–1.26) | 0.098 |
Chest pain, n (%) | ||||
Typical | 318 (78.7) | 32 (35.6) | 1 (reference) | <0.001 |
Atypical | 37 (9.2) | 20 (22.2) | 5.37 (2.79–10.33) | |
No chest pain | 49 (12.1) | 38 (42.2) | 7.71 (4.41–13.47) | |
Other symptom, n (%) | 160 (39.6) | 55 (61.1) | 2.40 (1.50–3.83) | <0.001 |
Radiating pain, n (%) | 125 (30.9) | 14 (15.6) | 0.41 (0.22–0.76) | 0.004 |
Symptom onset to arrival, n (%) | ||||
≤ 6 h | 319 (79.0) | 64 (71.1) | 1 (reference) | 0.186 |
6-24 h | 50 (12.4) | 13 (14.4) | 1.30 (0.67–2.52) | |
> 24 h | 35 (8.7) | 13 (14.4) | 1.85 (0.93–3.69) | |
Ambulance arrival, n (%) | 181 (44.8) | 46 (51.1) | 1.29 (0.82–2.04) | 0.278 |
Hemodynamic instability, n (%) | 73 (18.1) | 15 (16.7) | 0.91 (0.49–1.67) | 0.753 |
Positive baseline biomarker, n (%) | 184 (45.5) | 15 (16.7) | 0.24 (0.13–0.43) | <0.001 |
Location of STE, n (%) | ||||
Anterior | 155 (38.4) | 54 (60.6) | 1 (reference) | |
Inferior | 165 (40.8) | 25 (27.8) | 0.44 (0.26–0.73) | 0.002 |
Posterolateral | 14 (3.5) | 5 (5.6) | 1.03 (0.35–2.98) | 0.964 |
Diffuse | 70 (17.3) | 6 (6.7) | 0.25 (0.10–0.60) | 0.002 |
Height of maximal STE (mm) | 3.3 ± 2.1 | 2.4 ± 1.1 | 0.72 (0.61–0.85) | <0.001 |
Number of leads with STE | 3.3 ± 1.2 | 2.8 ± 1.0 | 0.61 (0.47–0.81) | <0.001 |
No reciprocal change, n (%) | 181 (44.8) | 71 (78.9) | 4.60 (2.68–7.92) | <0.001 |
Concave morphology of STE, n (%) | 162 (40.1) | 81 (90.0) | 13.4 (6.56–27.53) | <0.001 |
Q wave, n (%) | 21 (5.2) | 0 | <0.01 (<0.01- > 99.99) | 0.971 |
LVH, n (%) | 52 (12.9) | 18 (20.0) | 1.69 (0.94–3.06) | 0.082 |
Variables | Beta | OR (95% CI) |
P value | Risk score |
---|---|---|---|---|
Age | ||||
≥ 65 years | 1 (reference) | 0 | ||
< 65 years | 0.93 | 2.54 (1.35–4.89) | 0.004 | 1 |
Chest pain | ||||
Typical | 1 (reference) | 0 | ||
Atypical | 2.00 | 7.40 (3.27–17.14) | <0.001 | 2 |
No | 2.49 | 12.04 (5.92–25.63) | <0.001 | 2.5 |
Reciprocal change | ||||
Yes | 1 (reference) | 0 | ||
No | 1.57 | 4.80 (2.54–9.51) | <0.001 | 1.5 |
Concave morphology of STE | ||||
Yes | 2.68 | 14.54 (6.87–34.37) | <0.001 | 3 |
No | 1 (reference) | 0 |
Validation of the model
Derivation | Internal validation | External validation | |
---|---|---|---|
Sensitivity % (95% CI) | 83.3 (75.6–97.0) | 81.8 (65.7–97.9) | 81.8 (65.7–97.9) |
Specificity % (95% CI) | 76.2 (72.1–80.4) | 74.3 (65.7–82.8) | 64.8 (57.9–71.8) |
Positive predictive value % (95% CI) | 43.9 (36.4–51.3) | 40.9 (26.4–55.4) | 22.0 (13.0–30.9) |
Negative predictive value % (95% CI) | 93.4 (93.1–97.7) | 94.9 (90.1–99.8) | 96.7 (93.6–99.9) |
Accuracy % (95% CI) | 77.5 (73.9–81.2) | 75.6 (68.0–83.2) | 66.7 (60.2–73.1) |
Aetiologies of false-positive STEMI
Final diagnosis, N (%) | Total | Patients with CAG |
---|---|---|
Coronary spasm | 38 (28.4) | 26 (38.8) |
Primary rhythm disturbance | 26 (19.4) | 10 (14.9) |
Structural/valvular heart disease | 17 (12.7) | 8 (11.9) |
Myocarditis/pericarditis | 8 (6.0) | 5 (7.5) |
Stress induced cardiomyopathy | 4 (3.0) | 2 (3.0) |
Hypertensive emergency | 2 (1.5) | 0 |
Pulmonary embolism | 1 (0.7) | 0 |
Others | 17 (12.7) | 4 (6.0) |
No diagnosis | 21 (15.7) | 12 (17.9) |
Total | 134 | 67 |