Multivariable logistic regression model with in-hospital mortality as dependent variable and the guideline-recommended cut-off level of contact-to-balloon time (≤90 min) for four groups of symptom onset as independent variable adjusted to the indicated confounders
| Variable | OR | 95% CI | P value |
| Symptom-onset-to-first-medical-contact time (S2C) groups | |||
| Group 1 (S2C≤1 hour) | 0.555 | 0.456 to 0.675 | <0.0001 |
| Group 2 (1 hour<S2C≤2 hours) | 0.803 | 0.560 to 1.151 | |
| Group 3 (2 hours<S2C≤6 hours) | 0.769 | 0.558 to 1.060 | |
| Group 4 (6 hours<S2C≤24 hours) | 0.762 | 0.509 to 1.142 | |
| Age (year) | 1.054 | 1.047 to 1.062 | <0.0001 |
| Female gender | 1.395 | 1.200 to 1.622 | <0.0001 |
| Hypertension | 0.785 | 0.676 to 0.911 | 0.0014 |
| Diabetes mellitus | 1.384 | 1.170 to 1.636 | 0.0001 |
| Family history | 0.636 | 0.498 to 0.812 | 0.0003 |
| Smoker | 0.758 | 0.641 to 0.897 | 0.0012 |
| Previous stroke | 1.442 | 1.101 to 1.890 | 0.0079 |
| Renal failure | 1.552 | 1.231 to 1.956 | 0.0002 |
| No of coronary arteries narrowed | |||
| 0 versus LMCA | 0.171 | 0.030 to 0.971 | 0.0462 |
| one versus LMCA | 0.491 | 0.276 to 0.902 | 0.0219 |
| two versus LMCA | 0.551 | 0.301 to 1.007 | 0.0528 |
| three versus LMCA | 0.604 | 0.332 to 1.100 | 0.0992 |
| ECG (STEMI site) | |||
| Inferior versus anterior | 0.642 | 0.488 to 0.844 | 0.0015 |
| LBBB versus anterior | 0.747 | 0.460 to 1.213 | 0.2383 |
| Lateral versus anterior | 0.534 | 0.365 to 0.783 | 0.0013 |
| Chronic total occlusion in NIRA | |||
| RCA | 1.682 | 1.289 to 2.194 | 0.0001 |
| RCX | 1.722 | 1.286 to 2.306 | 0.0003 |
| LAD | 1.468 | 1.106 to 1.949 | 0.0079 |
| Recanalisation | |||
| Graft versus LAD | 1.313 | 0.726 to 2.375 | 0.3674 |
| LMCA versus LAD | 2.031 | 1.266 to 3.260 | 0.0033 |
| RCA versus LAD | 1.043 | 0.780 to 1.395 | 0.775 |
| LCX versus LAD | 1.245 | 0.932 to 1.663 | 0.1374 |
| TIMI angiographic flow grade after PCI (Score ≤2 vs 3) | 4.053 | 3.361 to 4.887 | <0.0001 |
Data are presented as ORs and their 95% CI.
CABG, coronary artery bypass grafting; cath. lab, catheterisation laboratory; CTO, chronic total occlusion; ECG, electrocardiogram; ECMO, extracorporeal membrane oxygenation; EMS, emergency medical service; IABP, intra-aortic balloon pump; LAD, left anterior descending artery; LBBB, left bundle branch block; LCA, left coronary artery; LCX, left circumflex artery; LMCA, left main coronary artery; MI, myocardial infarction; NIRA, non-infarct-related arteries; OHCA, out-of-hospital cardiac arrest; RCA, right coronary artery; TIMI, Thrombolysis In Myocardial Infarction score.