Treatment of sleep-disordered breathing in heart failure impacts cardiac remodeling: Insights from the CAT-HF Trial

Background: Sleep-disordered breathing (SDB), including central and obstructive sleep apnea, is a marker of poor prognosis in heart failure (HF) and may worsen cardiac dysfunction over time. Treatment of SDB with adaptive servoventilation (ASV) may reverse pathologic cardiac remodeling in HF patients.

Methods: The Cardiovascular Improvements with Minute Ventilation-targeted Adaptive Servo-Ventilation Therapy in Heart Failure (CAT-HF) trial randomized patients with acute decompensated HF and confirmed SDB to either optimal medical therapy (OMT) or treatment with ASV and OMT. Patients with reduced ejection fraction (HFrEF) or preserved EF (HFpEF) were included. Echocardiograms, performed at baseline and 6 months, assessed cardiac size and function and evaluated cardiac remodeling over time. The CAT-HF trial was stopped early in response to the SERVE-HF trial, which found increased mortality among HFrEF patients with central sleep apnea treated with ASV.

Results: Of the 126 patients enrolled prior to trial cessation, 95 had both baseline and 6-month echocardiograms (77 HFrEF and 18 HFpEF). Among HFrEF patients, both treatment arms demonstrated a significant increase in EF: +4.3% in the ASV group (.0004) and +4.6% in OMT alone (P = .007) and a significant decrease in LV end-systolic volume index: -9.4 mL/m² in the ASV group (P = .01) and -8.6 mL/m² in OMT alone (P = .003). Reductions in left atrial (LA) volume and E/e' were greater in the ASV arm, whereas patients receiving OMT alone demonstrated more improvement in right ventricular function. HFpEF patients treated with ASV also had a decrease in LA size that was greater than those receiving OMT alone. Although there were significant intragroup changes within the ASV + OMT and OMT-alone groups, there were no significant intergroup differences at 6 months.

Conclusions: Significant reverse LV remodeling was seen among HFrEF patients with SDB regardless of treatment allocation. Substantial reductions in LA volume among HFrEF and HFpEF patients receiving ASV suggest that ASV treatment may also improve diastolic function and warrant further investigation.