Table 5.
Cox Regression Model
| Variable | Hazard Ratio (95% CI) | Beta Coefficient | Standard Error | Significance | |
|---|---|---|---|---|---|
| AF/AFL | 2.07 | (1.33–3.23) | 0.73 | 0.23 | 0.001 |
| QRS abnormality | 1.09 | (0.75–1.59) | 0.08 | 0.19 | 0.662 |
| ST‐T wave abnormality | 1.06 | (0.79–1.43) | 0.06 | 0.15 | 0.692 |
| Initial hs‐cTnT ≥20 ng/L | 4.57 | (3.02–6.92) | 1.52 | 0.21 | <0.001 |
| Age per year | 1.04 | (1.03–1.05) | 0.04 | 0.01 | <0.001 |
| Male sex | 1.25 | (0.91–1.72) | 0.22 | 0.16 | 0.169 |
| Hypertension | 1.03 | (0.69–1.52) | 0.03 | 0.20 | 0.892 |
| Diabetes mellitus | 1.32 | (0.96–1.80) | 0.28 | 0.16 | 0.084 |
| CKD | 1.06 | (0.75–1.52) | 0.06 | 0.18 | 0.732 |
| Primary lung disease | 1.27 | (0.86–1.87) | 0.24 | 0.20 | 0.232 |
| Coronary artery disease | 1.56 | (1.04–2.33) | 0.44 | 0.21 | 0.032 |
| Obesity | 1.16 | (0.83–1.62) | 0.14 | 0.17 | 0.401 |
| HFrEF | 1.23 | (0.73–2.07) | 0.21 | 0.27 | 0.442 |
| HFpEF | 1.10 | (0.62–1.96) | 0.10 | 0.30 | 0.748 |
| Active cancer | 1.87 | (1.00–3.48) | 0.63 | 0.32 | 0.049 |
| History of cancer | 1.10 | (0.64–1.89) | 0.09 | 0.28 | 0.742 |
In this Cox regression model, initial high sensitivity troponin T (hs‐cTnT) ≥20, older age, a rhythm diagnosis of AF/AFL versus sinus rhythms, ectopic atrial rhythms, and atrially paced rhythms, a history of CAD, and active cancer were associated with increased morality. The variable effect size of ECG abnormalities on 30‐day mortality based on whether initial high sensitivity cardiac troponin T (hs‐cTnT) was >20 ng/L was further explored in this model. Three separate interaction terms (between elevated hs‐cTnT + each individual ECG abnormality [AF/AFL, QRS abnormalities, and ST‐T wave abnormalities] were tested. These 3 interaction terms were added to the model alone (without the other 2 interaction terms) or together (all 3 interaction terms added to the model). Neither of these interaction terms were significant. These interaction terms were therefore omitted from the model. AF/AFL indicates atrial fibrillation or atrial flutter, CKD indicates stage 3 or greater chronic kidney disease, HFrEF indicates heart failure with reduced ejection fraction which was defined as a clinical diagnosis of systolic heart failure or a baseline echocardiogram with left ventricular ejection fraction <50%, HFpEF indicates heart failure with preserved ejection fraction.