Abstract 14534: “Proportional Heart Rate Index” Predicts Mortality and need for Emergency Defibrillation, In Systolic Heart Failure Patients with a Narrow QRS
Background: An ambulatory electrocardiographic recording for 24-hours (Holter recording) is commonly used for risk stratification in heart failure patients. Autonomic variability is a well known predictor for both morbidity and mortality in cardiovascular disease as well as in heart failure patients. Accordingly, we assessed via a standard Holter recording, a new practical parameter which may reflect autonomic fluctuation in heart rate. This parameter termed as “Proportional Heart rate index” (PHRI) is easily calculated through the standard Holter report as: (Maximal-Minimal heart rate) / Minimal heart rate) × 100.
Patients and Methods: We analyzed and correlated several arrhythmic and clinical parameters with mortality defined either as death or need for emergent defibrillation. Patients with either atrial fibrillation or wide QRS (≥ 120 msec) were excluded from the final analysis which included 104 patients , mean age 60.5±13.9 years, 81 (78%) were males. Mean New York Heart Association Class was 2.5±0.8 and mean LV ejection fraction 28±10. A total of 100 (95%) patients were treated with beta blockers. Over five years of follow-up period, 21 (20%) patients died or had an emergency defibrillation. The evaluated parameters for mortality prediction included: ventricular tachycardia, ventricular premature beats, Proportional Heart rate index, ischemic etiology, LVEF and NYHA Class.
Results: PHRI value < 90% was significantly associated with mortality in univariable analysis (P= 0.001; OR: 6.1, CI 95% 2.1–17.7). Moreover, even after adjustment for other significant prognostic markers such as age, gender, BMI, NYHA Class, ischemic etiology, LVEF and arrhythmic parameters including non-sustained ventricular tachycardia and VPB'S, the PHRI remained significant and dominant parameter for prediction of mortality (P= 0.001; OR: 7.46, 95% CI: 2.2–24.3).
Conclusions: PHRI derived from a standard Holter recording was found to highly correlate with mortality/ need for emergent defibrillation in heart failure patients with narrow QRS complex. The significance of this specific parameter was far beyond several other known clinical parameters.
- © 2010 by American Heart Association, Inc.