Abstract 5923: Increased Frequency of High Heart Rate Episodes is Associated with Heart Failure Decompensation
The time course of cardiac arrhythmia occurrences and heart failure decompensation (HFD) events has not been well understood. To determine whether high heart rate (HHR) episodes occur more frequently prior to HFD events, the temporal relationship between HHR episodes and HFD events was analyzed from the COMPASS-HF study. The COMPASS-HF study included 274 NYHA class III-IV patients with an implantable hemodynamic monitor (IHM). In addition to monitoring hemodynamic status, the IHMs were set up to detect and store HHR episodes defined as a sensed ventricular HR > 150 bpm for at least 12 of 16 consecutive cardiac cycles. The number of IHM detected HHR episodes during the first 6-months of enrollment in the study was compared to HFD events by two methods:
within patients, by comparing HHR episode rate before and after a HFD event in patients with a single HFD event and
between patients, by comparing HHR episode rate in patients with HFD events (prior to the first HFD event) to HHR episode rate in patients without HFD events.
For those patients with one HFD event (n = 53 patients), HHR episode rates (# of HHR episodes/day) were 0.36 ± 0.82 and 0.05 ± 0.11 (p < 0.01) before and after the HFD event, respectively. Monitoring durations were 94 ± 4 days for before the HFD event and 91 ± 50 days for after the event. HHR episode rates were 0.30 ± 0.77 and 0.19 ± 0. 61 (p < 0.01) for patients with HFD events (n = 104 patients) and without HFD events (n = 170 patients), respectively. Monitoring durations prior to the first HFD event, and in patients without HFD events were 77 ± 46 days and 178 ± 41 days. IHM detected HHR episodes occurred seven times more frequently prior to HFD events than after HFD events. While the IHM could not differentiate the types of HHR rhythms, these data demonstrate a clear association between the rate of HHR episodes and HFD events. The cause and effect relation remains to be more clearly defined.