Heart rate score in remote monitoring: An additional tool for predicting outcomes in heart failure with reduced ejection fraction

Background: Heart rate score (HRS) >= 70% has been associated with arrhythmic events and mortality but these studies were not specific for heart failure (HF) patients. We hypothesized that HRS >= 70% obtained from remote monitoring (RM) is associated with HF hospitalizations and arrhythmic events in HF with reduced ejection fraction (HFrEF). Methods: HRS was calculated from RM in patients with HFrEF and ICD or CRT-D. Two groups were defined: HRS >= 70% (G1, n = 55) and HRS < 70% (G2, n = 48) Results: A total of 103 patients were included (64.4 +/- 13.04 years, 69.9% male, mean left ventricular ejection fraction (LVEF) 33.62 +/- 11.97% and FUP 61.7 +/- 38.87 months). The device was CRT-D in 59.2% and ICD in 40.8% and the majority (90.3%) had the device implanted in primary prevention. G1 patients were more frequently male (p = .017) and had more coronary disease (p = .035). HRS >= 70% was an independent predictor for unplanned HF hospitalizations (OR: 1.905 (95% CI: 1.328-3.649), p < .001)). The indication for device implantation (primary vs. secondary prevention), type of device, NYHA class, age, gender and LVEF were not independent predictors of the outcome. VF (4.9 +/- 20.0 G1 vs. 1.1 +/- 5.47 G2, p = .046) and VT episodes were more prevalent in G1 (3.1 +/- 8.93 G1 vs. 0.3 +/- 1.59 G2, p = .026), as well as appropriate device shocks (4.3 +/- 12.06 G1 vs. 0.3 +/- 1.49 G2, p = .023). There was no difference in inappropriate shocks or mortality outcomes between groups. Conclusion: HRS >= 70% obtained from RM was an independent predictor of HF hospitalizations and was associated with arrhythmic events with VT and VF episodes and appropriate device shocks in HFrEF patients.