Risk Stratification in Ischemic Heart Failure Patients with Linear and Nonlinear Methods of Heart Rate Variability Analysis

Heart failure has a current prevalence of 14 million concerned people in Europe and is thus a major and escalating public health problem in the industrialized countries with ageing populations. A five-year mortality rate between 62–75% in men and 38–42% in women related to the initial diagnosis of heart failure was documented in the Framingham study. The aim of this study was to investigate the suitability of linear (according the Task Force recommendations) and nonlinear (symbolic dynamics - SD and detrended fluctuation analysis - DFA) methods of heart rate variability (HRV) analysis for risk stratification in patients with ischemic heart failure (IHF). From 221 low risk (LR: stable condition) and 35 high risk (HR: cardiac death) IHF patients HRV from 24h long-term BBI time series were analyzed. Seven measures from all applied methods revealed significant differences (p<0.05) discriminating LR and HR patients. These results suggest that HRV analysis according to the Task Force (only frequency domain), SD and DFA are useful methods for enhanced risk stratification in IHF patients.