Performance of the clinical chemistry score for identifying patients at low and high risk for myocardial infarction or death within 30 days after presentation to the emergency department*
| Score cut-off | No. of participants with MI or who died† | No. of participants with no MI or death |
|---|---|---|
| CCS with hs-cTnI test | ||
| CCS > 0 | 727 | 3140 |
| CCS = 0 | 0 | 378 |
| Sensitivity, % (95% CI) | 100 (99.5–100) | |
| NPV, % (95% CI) | 100 (98.9–100) | |
| Negative likelihood ratio | 0 (0–0.05) | |
| Patients at low risk, % (95% CI) | 8.9 (8.1–9.8) | |
| CCS = 5 | 358 | 119 |
| CCS < 5 | 369 | 3399 |
| Specificity, % (95% CI) | 96.6 (96.0–97.2) | |
| PPV, % (95% CI) | 75.1 (71.3–78.5) | |
| Positive likelihood ratio | 14.6 (12.0–17.6) | |
| Patients at high risk, % (95% CI) | 11.2 (10.3–12.2) | |
| CCS with hs-cTnT test | ||
| CCS > 0 | 726 | 3075 |
| CCS = 0 | 1 | 443 |
| Sensitivity, % (95% CI) | 99.9 (99.2–100) | |
| NPV, % (95% CI) | 99.8 (98.4–100) | |
| Negative likelihood ratio | 0.01 (0–0.06) | |
| Patients at low risk, % (95% CI) | 10.5 (9.6–11.4) | |
| CCS = 5 | 342 | 212 |
| CCS < 5 | 385 | 3306 |
| Specificity, % (95% CI) | 94.0 (93.1–94.7) | |
| PPV, % (95% CI) | 61.7 (58.1–65.2) | |
| Positive likelihood ratio | 7.8 (6.7–9.1) | |
| Patients at high-risk, % (95% CI) | 13.1 (12.1–14.1) | |
| hs-cTnI test only | ||
| ≥ 5 ng/L | 702 | 1543 |
| < 5 ng/L | 25 | 1975 |
| Sensitivity, % (95% CI) | 96.6 (95.0–97.8) | |
| NPV, % (95% CI) | 98.8 (98.2–99.2) | |
| Negative likelihood ratio | 0.06 (0.04–0.09) | |
| > 26 ng/L | 537 | 239 |
| ≤ 26 ng/L | 190 | 3279 |
| Specificity, % (95% CI) | 93.2 (92.3–94.0) | |
| PPV, % (95% CI) | 69.2 (65.8–72.4) | |
| Positive likelihood ratio | 10.9 (9.6–12.4) | |
| hs-cTnT test only | ||
| ≥ 6 ng/L | 714 | 2262 |
| < 6 ng/L | 13 | 1256 |
| Sensitivity, % (95% CI) | 98.2 (97.0–99.0) | |
| NPV, % (95% CI) | 99.0 (98.3–99.5) | |
| Negative likelihood ratio | 0.05 (0.03–0.09) | |
| > 14 ng/L | 640 | 922 |
| ≤ 14 ng/L | 87 | 2596 |
| Specificity, % (95% CI) | 73.8 (72.3–75.2) | |
| PPV, % (95% CI) | 41.0 (38.5–43.5) | |
| Positive likelihood ratio | 3.4 (3.2–3.6) | |
Note: CCS = clinical chemistry score, CI = confidence interval, hs-cTnI = high-sensitivity cardiac troponin I, hs-cTnT = high-sensitivity cardiac troponin T, MI = myocardial infarction, NPV = negative predictive value, PPV = positive predictive value.
↵* Combined cohorts, n = 4245.
↵† Unless specified otherwise.