Table 2:
Performance of high-sensitivity troponin T assay in diagnosing myocardial infarction at presentation and two hours later
| Cut-off value of assay; performance measure | Time of assay; % (95% CI) | |
|---|---|---|
| At presentation | 2 h after presentation | |
| ≥ 14 ng/L (99th percentile)* | ||
| Sensitivity | 88.3 (83.3–91.8) | 92.2 (88.1–85.0) |
| Specificity | 81.7 (80.5–82.7) | 79.7 (78.6–80.5) |
| Positive-predictive value | 57.5 (54.5–59.7) | 55.9 (53.4–57.6) |
| Negative-predictive value | 96.2 (94.7–97.3) | 97.3 (95.9–98.3) |
| Accuracy | 83.2 (81.2–84.7) | 82.4 (80.6–83.7) |
| ≥ 5 ng/L (limit of detection†) | ||
| Sensitivity | 93.7 (89.4–96.4) | 95.6 (91.7–97.8) |
| Specificity | 58.4 (57.3–59.2) | 53.7 (52.6–54.3) |
| Positive-predictive value | 38.6 (36.9–39.8) | 36.6 (35.1–37.4) |
| Negative-predictive value | 97.1 (95.1–98.3) | 97.8 (95.8–98.9) |
| Accuracy | 66.1 (64.3–67.3) | 62.8 (61.1–63.8) |
| ≥ 3 ng/L (limit of blank‡) | ||
| Sensitivity | 95.6 (91.8–97.8) | 98.1 (94.9–99.4) |
| Specificity | 47.8 (46.7–48.4) | 42.2 (41.3–42.6) |
| Positive-predictive value | 33.9 (32.5–34.6) | 32.3 (31.2–32.7) |
| Negative-predictive value | 97.5 (95.3–98.8) | 98.7 (96.6–99.6) |
| Accuracy | 58.3 (56.6–97.8) | 45.5 (45.0–46.9) |
Note: CI = confidence interval.
*
At or above the 99th percentile of the general population.
†
Limit of detection = the lowest quantity or concentration of an analyte that can be reliably detected with a given analytical method.
‡
Limit of blank = the highest apparent concentration of an analyte expected to be found in a sample containing no analyte.