Risk stratification in congestive heart failure patients using a model-based approach to heart rate turbulence characterization

Heart rate turbulence (HRT) is commonly assessed by two parameters: turbulence onset (TO) and turbulence slope (TS), both obtained by averaging RR tachograms following a ventricular premature beat (VPB). It has been recently shown that a model-based detection-theoretical approach results in HRT indices outperforming TO/TS in identifying the presence or absence of HRT. The aim of this work is to evaluate the risk stratification ability of this approach, as compared with the classical parameters TO and TS, in a population of 96 ischemic patients with mild to moderate congestive heart failure. We found significant differences (Mann-Withney U test) between survivors and cardiac death groups for TS and the new parameter T_¿(x). Survival analysis showed that T_¿(x) is the HRT index with highest association to risk of cardiac death (hazard ratio=2.8, p =0.008). Results show improved risk stratification of the new description of HRT with respect to classical parameters.