Introduction: Heart rate (HR), ventricular arrhythmias (VA) and QRS complex width analysis is used for ECG-based noninvasive risk evaluation for permanent atrial fibrillation(PAF) patients. We speculate: impaired circadian HR changeability is associated with higher PAF patients mortality risk.
Methods: In cohort of 253 PAF patients (dead - 74 pts, 34(46%) male, mean age(SD) - 78(7.8), alive – 179pts, 79(44%) male, age - 74(10.1) HM records archived in 2007-2010 (follow-up – 47(8.4) month) were analysed. Primary end-point – total mortality. Characteristics of 24-hours HR changes were calculated, analysed using univariate analysis and included in logistic regression(LR) models. ROC curves were obtained to establish optimal cut-off point for continuous characteristics and compare LR models including patient clinical characteristics only, HM data only and combined models including clinical and HM parameters.
Results: All calculated 24-hours HR changeability parameters were statistically significantly lower in dead patients (table 1). Maximum risk assessment model capability(AUC) was obtained by including 24-hour HR parameters (table 2).
Conclusions: PAF patient with lower 24-hours HR changeability are in higher mortality risk. Inclusion of circadian HR characteristics in risk assessment could improve mortality prediction for PAF patients.