Electrocardiographic and autonomic univariate predictors of death or non-fatal myocardial infarction
| 30 day follow up | 12 month follow up | |||||
|---|---|---|---|---|---|---|
| Variable | No event (n=288) | Event (n=15) | p Value | No event (n=261) | Event (n=28) | p Value |
| LF:HF, low frequency to high frequency ratio; mean NN, mean of all coupling intervals between qualified beats; pNN50, proportion of adjacent RR intervals more than 50 ms different; RMSSD, root mean square of the difference of successive RR intervals; SD, mean of all 5 minute standard deviations of RR intervals; SDANN, standard deviation of 5 minute mean RR intervals; SDNN, standard deviation about the mean. | ||||||
| Data for pNN50 and LF:HF are median (interquartile range) and for SDNN, mean NN, RMSSD, SD, and SDANN are mean (standard deviation). | ||||||
| Admission ECG | ||||||
| T wave inversion | 142 (49.3%) | 13 (86.7%) | 0.005 | 124 (47.5%) | 24 (85.7%) | 0.001 |
| ST depression | 84 (29.2%) | 4 (26.7) | 0.84 | 71 (27.2%) | 12 (42.9%) | 0.09 |
| Holter monitoring | ||||||
| Any ST depression | 76 (28.6%) | 9 (69.2%) | 0.002 | 67 (27.2) | 15 (65.2%) | <0.0001 |
| Any ST elevation | 48 (18.1%) | 9 (69.2%) | <0.0001 | 43 (17.5%) | 12 (52.2%) | <0.0001 |
| Any ST shift | 106 (39.9%) | 12 (92.3%) | <0.0001 | 95 (38.6%) | 19 (82.6%) | <0.0001 |
| Heart rate variability | ||||||
| pNN50 (%) | 9.8 (3.4–17.7) | 9.1 (5.2–12.8) | 0.92 | 8.1 (3.4–17.6) | 10.8 (5.9–12.8) | 0.46 |
| SDNN (ms) | 113.3 (32.1) | 93.7 (17.0) | 0.03 | 113.1 (33.3) | 98.8 (26.4) | 0.05 |
| Mean NN (ms) | 910.9 (158.1) | 808.0 (122.9) | 0.03 | 912.4 (156.3) | 804.7 (138.3) | 0.002 |
| RMSSD (ms) | 41.0 (22.3) | 42.0 (19.3) | 0.87 | 40.0 (22.6) | 45.8 (26.4) | 0.27 |
| SD (ms) | 41.7 (17.9) | 37.7 (9.8) | 0.39 | 41.1 (18.4) | 38.4 (15.2) | 0.49 |
| SDANN (ms) | 100.8 (28.7) | 81.9 (14.8) | 0.02 | 100.8 (29.5) | 85.7 (21.7) | 0.018 |
| LF:HF | 1.67 (0.98–3.52) | 2.59 (1.11–6.44) | 0.47 | 1.9 (0.99–3.56) | 1.36 (1.08–2.77) | 0.31 |