| Clinical judgment GP | CDR variant 1 | CDR variant 2 | CDR variant 3 | CDR variant 4 | CDR variant 5 a,c | ||
| CDR based on… | ST-depressions | / | 1 | 1 | / | / | / |
| ST-elevations | / | 1 | 1 | / | / | / | |
| Dyspnoea | / | 1 | 1 | 1 | 1 | / | |
| Feeling of pressure chest | / | 1 | 1 | 1 | 1 | / | |
| Absent lateral chest pain left | / | 1 | 1 | 1 | 1 | – | |
| Age ≤45.5, ≥68.5 years | / | / | / | / | / | / | |
| Male sex | / | / | / | / | / | / | |
| Cardiac murmur | / | / | / | / | / | / | |
| POCT H-FABP result positive | / | 1 | / | 1 | / | / | |
| CDR and/or decision characteristics | Maximum score | / | 6 | 5 | 4 | 3 | / |
| Considered negative if… | GP did not refer | ≤1 | ≤1 | ≤1 | ≤1 | / | |
| Patients with a negative versus positive score | 191 negative, 112 positive | 145 negative, 158 positive | 147 negative, 156 positive | 157 negative, 146 positive | 161 negative, 142 positive | 46 negative, 204 positive | |
| Rule-out characteristics | Sens; NPV for ACS [95% CI] | Sens 75.0 [56.2 to 87.9]; NPV 95.8 [91.6 to 98.0] | Sens 87.5 [70.1 to 95.9]; NPV 97.2 [92.6 to 99.1] | Sens 81.2 [63.0 to 92.1]; NPV 95.9 [90.9 to 98.3] | Sens 78.1 [60.0 to 90.0]; NPV 95.5 [90.7 to 98.0] | Sens 68.8 [49.9 to 83.3]; NPV 93.8 [88.6 to 96.8] | Sens 100 [84.5 to 100]; NPV 100 [90.4 to 100] |
| FNs for ACS, n (% of total) | 8 (2.6) | 4 (1.3) | 6 (2.0) | 7 (2.3) | 10 (3.3) | 0 (0.0) | |
| TNs for ACS, n (% of total) | 183 (60.4) | 141 (46.5) | 141 (46.5) | 150 (49.5) | 151 (49.8) | 46 (18.4) | |
| Sens; NPV for AMI [95% CI] | Sens 70.4 [49.7 to 85.5]; NPV 95.8 [91.6 to 98.0] | Sens 88.9 [69.7 to 97.1]; NPV 97.9 [93.6 to 99.5] | Sens 81.5 [61.3 to 93.0]; NPV 96.6 [91.8 to 98.7] | Sens 77.8 [57.3 to 90.6]; NPV 96.2 [91.5 to 98.4] | Sens 66.7 [46.0 to 82.8]; NPV 94.4 [89.3 to 97.2] | Sens 81.5 [61.3 to 93.0]; NPV 0 [0 to 53.7] | |
| Rule-in characteristics | Spec; PPV for ACS [95% CI] | Spec 67.5 [61.6 to 73.0]; PPV 21.4 [14.5 to 30.4] | Spec 52.0 [45.9 to 58.1]; PPV 17.7 [12.3 to 24.8] | Spec 52.0 [45.9 to 58.1]; PPV 16.7 [11.4 to 23.7] | Spec 55.4 [49.2 to 61.3]; PPV 17.1 [11.6 to 24.4] | Spec 55.7 [49.6 to 61.7]; PPV 15.5 [10.2 to 22.7] | Spec 20.6 [15.6 to 26.7]; PPV 13.2 [9.1 to 18.8] |
| FPs for ACS, n (% of total) | 88 (29.0) | 130 (42.9) | 130 (42.9) | 121 (39.9) | 120 (39.6) | 177 (70.8) | |
| TPs for ACS, n (% of total) | 24 (7.9) | 28 (9.2) | 26 (8.6) | 25 (8.3) | 22 (7.3) | 27 (10.8) | |
| Spec; PPV for AMI [95% CI] | Spec 66.3 [60.4 to 71.8]; PPV 17.0 [10.8 to 25.5] | Spec 51.4 [45.4 to 57.5]; PPV 15.2 [10.2 to 22.0] | Spec 51.4 [45.4 to 57.5]; PPV 14.1 [9.2 to 20.8] | Spec 54.7 (48.6 to 60.7]; PPV 14.4 [9.3 to 21.4] | Spec 55.1 (49.0 to 61.0]; PPV 12.7 [7.9 to 19.6] | Spec 0.0 (0.0 to 2.1]; PPV 9.0 [5.8 to 13.5] | |
| Rule in or outb | Rule in, out ACS. Rule in, out AMI | Rule in, out ACS. Rule in, out AMI | Rule in, out ACS. Rule in, out AMI | Rule in, out ACS. Rule in, out AMI | Non-decisive | Rule out ACS |
aDenominator in calculations for CDR variant 5 is 250 patients, since CART was initially performed in a subgroup of 53 patients and internally validated in a subgroup of the remaining 250 patients.
bA CDR is considered as possibly relevant for rule in when the pre-test probability (based on the prevalence in the study population) of presence of an AMI (8.9%), or ACS (10.6%), is below the lower margin of the 95% CI of the PPV of the CDR. A CDR is considered as potentially relevant for rule-out when the pre-test probability of absence of an AMI (91.1%), or ACS (89.4%), is below the lower margin of the 95% CI of the NPV.
cIn addition to the predicting signs and symptoms derived from CART for ACS, two other symptoms were added to CDR variant 5 for AMI: systolic blood pressure ≥149 mmHg and bradycardia (heart rate <60/min), based on the CART analysis with AMI as an outcome.
ACS = acute coronary syndrome. AMI = acute myocardial infarction. CI = confidence interval. FNs = false negatives. FPs = false positives. H-FABP = heart-type fatty acid-binding protein. NPV = negative predictive value. NSTEMI = non-ST elevated myocardial infarction. POCT = point of care test. PPV = positive predictive value. Sens = sensitivity. Spec = specificity. SBP = systolic blood pressure. TNs = true negatives. TPs = true positives.