Rates of AMI and MACE stratified by the refined MACS rule risk groups
| Risk group (according to the MACS rule) | ||||
|---|---|---|---|---|
| Very low risk | Low risk | Moderate risk | High-risk | |
| Original MACS rule | ||||
| Total number of patients, n (%) | 123 (27.0) | 81 (17.8) | 207 (45.4) | 45 (9.9) |
| Number of patients with AMI (%, 95% CI) | 0 (0.0, 0.0 to 3.6) | 0 (0.0, 0.0 to 5.4) | 36 (17.4, 12.8 to 23.2) | 42 (93.3, 81.5 to 98.4) |
| Number of patients with MACE, n (%, 95% CI) | 2 (1.6, 0.08 to 6.1)* | 1 (1.2, 0.0 to 7.3) | 51 (24.6, 19.3 to 31.0) | 43 (95.6, 84.4 to 99.6) |
| Recalibrated MACS rule with automated IT h-FABP assay | ||||
| Total number of patients | 86 (18.9) | 99 (21.7) | 221 (48.5) | 50 (11.0) |
| Number of patients with AMI, n (%, 95% CI) | 0 (0.0, 0.0 to 5.1) | 0 (0.0, 0.0 to 5.4) | 33 (14.9, 10.8 to 20.3) | 45 (90.0, 78.2 to 96.0) |
| Number of patients with MACE, n (%, 95% CI) | 2 (2.3, 0.1 to 8.6)* | 0 (0.0, 0.0 to 4.5) | 49 (22.2, 17.2 to 28.1) | 46 (92.0, 80.7 to 97.4) |
The performance of the original MACS rule has also been reported elsewhere.10
*There were two MACEs in the ‘very low risk’ group using each h-FABP assay. Both were coronary stenoses that did not require coronary revascularisation.
AMI, acute myocardial infarction; h-FABP, heart-type fatty acid binding protein; MACE, major adverse cardiac events; MACS, Manchester Acute Coronary Syndromes.