Predictor | Unit | Unadjusted | Adjusted^{a} | ||
---|---|---|---|---|---|

HR (95% CI)^{b} | P | HR (95% CI)^{b} | P | ||

SDNN | −25 ms | 1.30 (1.09–1.55) | 0.004 | 1.08 (0.90–1.30) | 0.42 |

SDANN | −25 ms | 1.32 (1.09–1.59) | 0.004 | 1.09 (0.89–1.33) | 0.40 |

RMSSD | −1.5 ms | 1.00 (0.96–1.03) | 0.89 | 1.00 (0.97–1.04) | 0.78 |

pNN50 | −1.5 ms | 0.99 (0.92–1.05) | 0.64 | 1.02 (0.95–1.09) | 0.63 |

HRVTI | −10 | 1.24 (1.10–1.40) | <0.001^{c} | 1.14 (0.85–1.52) | 0.39 |

ULF | −0.5 ln (ms^{2}) | 1.24 (1.10–1.40) | <0.001^{c} | 1.09 (0.95–1.25) | 0.21 |

VLF | −0.5 ln (ms^{2}) | 1.18 (1.08–1.29) | <0.001^{c} | 1.07 (0.96–1.18) | 0.22 |

LF | −5 ln (ms^{2}) | 3.55 (1.63–7.70) | 0.001^{c} | 1.83 (0.77–4.31) | 0.16 |

HF | −5 ln (ms^{2}) | 1.85 (0.62–5.46) | 0.26 | 1.17 (0.41–3.29) | 0.76 |

LF/HF | −5 | 5.17 (2.12–12.62) | <0.001^{c} | 2.85 (1.10–7.35) | 0.03 |

Scaling exponent α_{1} | −0.25 | 1.75 (1.41–2.16) | <0.001^{c} | 1.46 (1.16–1.85) | 0.001^{c} |

Scaling exponent α_{2} | 0.25 | 3.73 (1.86–7.49) | <0.001^{c} | 1.25 (0.61–2.53) | 0.54 |

HRT category^{d} | 0, 1, 2 | 1.95 (1.22–3.11) | 0.005 | 1.34 (0.81–2.22) | 0.26 |

DC | −1 ms | 1.36 (1.15–1.60) | <0.001^{c} | 1.13 (0.96–1.34) | 0.14 |

HR, hazard ratio; HRV, heart rate variability; SDNN, SD of normal-to-normal intervals during 24 hours; SDANN, SD of the averages of NN intervals in all 5-minute segments during 24 hours; RMSSD, square root of the mean square of differences between adjacent NN intervals; pNN50, percentage of the number of pairs of adjacent NN R-R intervals differing >50 ms in the total NN intervals; HRVTI, heart rate variability triangular index; ULF, ultra-low frequency (≤0.003 Hz) power; VLF, very-low frequency (0.003–0.04 Hz) power; LF, low frequency (0.04–0.15 Hz) power; HF, high frequency (0.15–0.40 Hz) power; HRT, heart rate turbulence; DC, deceleration capacity.

↵a Adjusted for age, left ventricular ejection fraction, serum albumin, C-reactive protein, and calcium × phosphate.

↵b HR for 1 unit change in continuous variables or for the presence of features.

↵c Significant after correcting for multiple analyses of 14 variables (

*P*<0.003 for type 1 error level of 0.05).↵d

*n*=68 for survivors and*n*=37 for nonsurvivors.