Portable recording for detecting sleep disorder breathing in patients under the care of a heart failure clinic.

Background: Sleep disordered breathing (SDB) has important clinical implications in patients with congestive heart failure (CHF). We performed portable recording in unselected CHF patients on contemporary therapy. Data on the interactions of SDB in patients supervised at heart failure clinics are rare and we illustrate diversities of obstructive sleep apnoea (OSA) and central sleep apnoea (CSA).

Methods: We studied 176 consecutive subjects on contemporary medical therapy with a median left ventricular ejection fraction of 25.0 % (range 7-35%) and median NT-pro BNP levels of 3,413.0 pg/ml (range 305.1-35,000.0 pg/ml). Participants underwent prospective overnight portable recording.

Results: 50% presented with an at least moderate form of nocturnal breathing disorder [apnoea-hypopnoea index (AHI) ≥15/h]. Only 15 patients (17.1%) with AHI ≥15/h reported excessive daytime sleepiness. Irrespective of left ventricular ejection fraction, patients with CSA had higher levels of NT-pro BNP compared to patients with OSA (differences in medians = 2,639.0 pg/ml, p = 0.016), and compared to patients with an AHI <15/h (differences in medians = 2,710.0 pg/ml, p < 0.001). OSA affected 26 patients (14.8%).

Conclusions: Patients with severe stable CHF on contemporary therapy have a prevalence of 50.0% of moderate to severe SDB. The natural cascade of the failing heart is initially characterised by absent SDB or OSA, whereas end-stage CHF is associated with CSA.