Cardiovascular Outcomes With Minute Ventilation–Targeted Adaptive Servo-Ventilation Therapy in Heart Failure: The CAT-HF Trial

Background Sleep apnea is common in hospitalized heart failure (HF) patients and is associated with increased morbidity and mortality. Objectives The CAT-HF (Cardiovascular Improvements With MV-ASV Therapy in Heart Failure) trial investigated whether minute ventilation (MV) adaptive servo-ventilation (ASV) improved cardiovascular outcomes in hospitalized HF patients with moderate-to-severe sleep apnea. Methods Eligible patients hospitalized with HF and moderate-to-severe sleep apnea were randomized to ASV plus optimized medical therapy (OMT) or OMT alone (control). The primary endpoint was a composite global rank score (hierarchy of death, cardiovascular hospitalizations, and percent changes in 6-min walk distance) at 6 months. Results 126 of 215 planned patients were randomized; enrollment was stopped early following release of the SERVE-HF (Adaptive Servo-Ventilation for Central Sleep Apnea in Systolic Heart Failure) trial results. Average device usage was 2.7 h/night. Mean number of events measured by the apnea-hypopnea index decreased from 35.7/h to 2.1/h at 6 months in the ASV group versus 35.1/h to 19.0/h in the control group (p < 0.0001). The primary endpoint did not differ significantly between the ASV and control groups (p = 0.92 Wilcoxon). Changes in composite endpoint components were not significantly different between ASV and control. There was no significant interaction between treatment and ejection fraction (p = 0.10 Cox model); however, pre-specified subgroup analysis suggested a positive effect of ASV in patients with HF with preserved ejection fraction (p = 0.036). Conclusions In hospitalized HF patients with moderate-to-severe sleep apnea, adding ASV to OMT did not improve 6-month cardiovascular outcomes. Study power was limited for detection of safety signals and identifying differential effects of ASV in patients with HF with preserved ejection fraction, but additional studies are warranted in this population.