Peak ectopy rate analysis for risk stratification of sudden death in heart failure

Aim of this paper is to propose a new parameter, based on 24-hour holter recording, that quantifies abnormal ventricular activity by calculating the peak ectopic rate (PEAK_ER) of every patient. This parameter is tested on a population of 200 heart failure (HF) patients in sinus rhythm (age (median [interquartile range]): 54 years [47-58], ejection fraction (EF): 23% [19-28]. During the 5 year follow-up 23 patients suddenly died. Classification obtained from PEAK_ER is compared with that from left ventricular ejection fraction (EF), non-sustained ventricular tachyarrhythmias (NSVT) and premature ventricular contractions per hour (PVC/h). We also considered combinations of PEAK_ER, NSVT and PVC/h with EF. End-points are total cardiac death (CD) and sudden cardiac death (SCD). Performances are assessed by total accuracy, sensitivity and specificity. On both end-points EF alone reaches best sensitivity and worst specificity; Peak_ER alone performs better than NSVT and slightly better than PVC/h; EF+Peak_ER performs on average slighly better than EF+NSVT and EF+PVC/h. In conclusion, results from present study indicate that investigation of time course of arrhythmic events may improve identification of patients with HF at increased risk of arrhythmic sudden death.