Phrenic nerve stimulation to treat patients with central sleep apnoea and heart failure

Abstract

Aims: The presence of central sleep apnoea (CSA) is associated with poor prognosis in patients with heart failure (HF). The aim of this analysis was to evaluate if using phrenic nerve stimulation to treat CSA in patients with CSA and HF was associated with changes in HF-specific metrics.

Methods and results: All patients randomized in the remedē System Pivotal Trial and identified at baseline with HF were included (n = 96). Effectiveness data from treatment and former control groups were pooled based on months since therapy activation. Changes from baseline to 6 and 12 months in sleep metrics, Epworth Sleepiness Scale, patient global assessment health-related quality of life, Minnesota Living with Heart Failure Questionnaire (MLHFQ), and echocardiographic parameters are reported. HF hospitalization, cardiovascular death, and the composite of HF hospitalization or cardiovascular death within 6 months are reported by the original randomized group assignment for safety assessment. Sleep metrics and quality of life improved from baseline to 6 and 12 months. At 12 months, MLHFQ scores changed by -6.8 ± 20.0 (P = 0.005). The 6-month rate of HF hospitalization was 4.7% in treatment patients (standard error = 3.3) and 17.0% in control patients (standard error = 5.5) (P = 0.065). Reported adverse events were as expected for a transvenous implantable system.

Conclusions: Phrenic nerve stimulation reduces CSA severity in patients with HF. In parallel, this CSA treatment was associated with benefits on HF quality of life.

Keywords: Central sleep apnoea; Heart failure; Phrenic nerve stimulation.

Figure 1

Composition of the pooled study population and follow‐up time points. As pre‐specified in the protocol, patients were implanted and randomized to treatment (therapy activated one month after implant) or control (therapy activated after the 6‐month assessments). This study design allowed for the pooling of 6‐ and 12‐month effectiveness data from the treatment and control groups based on months since therapy activation (baseline for these analyses). Patients in the treatment group accrued 6‐ and 12‐month data at the corresponding visits, whereas the control group accrued 6‐ and 12‐month data at the 12‐ and 18‐month visits due to the delay in initiating therapy. HF, heart failure; PSG, polysomnogram.

Figure 2

Percentage change in apnoea–hypopnoea index (AHI) from baseline to 12 months of therapy for each patient in the pooled population of patients with heart failure and polysomnogram data. The change from baseline following 12 months of active therapy for all subjects is shown. Patients with any decrease in AHI from baseline are shown in green bars and patients with any increase in AHI from baseline are shown in red bars.