title: Compression entropy contributes to risk stratification in patients with cardiomyopathy.
abstract: Sudden cardiac death (SCD) is a leading cause of mortality with an incidence of 3 million cases per year worldwide. Therapies for patients who have survived an SCD episode or have a high risk of developing lethal ventricular arrhythmia are well established and depend mainly on risk stratification. In this study we investigated the suitability of the non-linear measure compression entropy (Hc) for improved risk prediction in cardiac patients. We recorded 24-h Holter ECG for 300 patients with congestive heart failure (CHF). During a mean follow-up period of 12 months, 32 patients died due to a cardiac event. Hc depends on the compression parameters window length w and buffer length b, which were optimised by analysing a subgroup of patients. Compression entropies based on the beat-to-beat interval (BBI) were subsequently calculated and compared with standard heartrate variability parameters. Statistical analysis revealed significant differences between high- and low-risk CHF patients in standard HRV measures, as well as compression entropy based on the BBI (cardiac death, p = 0.005; SCD, p = 0.02). In conclusion, the implementation of non-linear compression entropy analysis in multivariate analysis seems to be useful for enhanced risk stratification of cardiac death, especially SCD, in ischaemic cardiomyopathy patients.
authors.affiliation: Department of Medical Engineering, University of Applied Sciences Jena, Jena, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Truebner
authors.forename: Iwona
authors.initials: I
authors.lastname: Cygankiewicz
authors.forename: Rico
authors.initials: R
authors.lastname: Schroeder
authors.forename: Mathias
authors.initials: M
authors.lastname: Baumert
authors.forename: Montserrat
authors.initials: M
authors.lastname: Vallverdú
authors.forename: Pere
authors.initials: P
authors.lastname: Caminal
authors.forename: Rafael
authors.initials: R
authors.lastname: Vazquez
authors.forename: Antoni
authors.initials: A
authors.lastname: Bayés de Luna
authors.forename: Andreas
authors.initials: A
authors.lastname: Voss
mesh_terms: D000368:Aged; D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000401:mortality*; D009202:Cardiomyopathies / Q000175:diagnosis* / Q000401:mortality*; D015897:Comorbidity; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D015716:Electrocardiography, Ambulatory / Q000706:statistics & numerical data*; D019277:Entropy; D006339:Heart Rate; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015999:Multivariate Analysis; D017711:Nonlinear Dynamics; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013030:Spain / Q000453:epidemiology