1300 Sleep Disordered Breathing, Obesity Hypoventilation and Severe Heart Failure with Reduced Ejection Fraction: CPAP as a Management Tool

Abstract Introduction Sleep disordered breathing is prevalent in persons with heart failure (HF). The prevalence of obesity in persons with HF is expected to increase with the obesity pandemic, together with the risk of sleep-related hypoventilation. Managing patients with these significant comorbidities presents unique challenges and considerations. We present a case of chronic HF with reduced ejection fraction (HFrEF) and obesity hypoventilation syndrome (OHS). Report of case(s) A 58-year-old man presented for titration polysomnography (PSG) with OHS (daytime PaCO2= 53 mmHg; BMI 35kg/m2), severe obstructive sleep apnea (OSA) (apnea-hypopnea index (AHI)=68) and mild central sleep apnea (CSA) (AHI=10), chronic hypoxic respiratory failure (4 liters/min domiciliary oxygen), and HFrEF (LVEF 10%) on domiciliary milrinone infusion. His dry weight was 115kg. Titration PSG was started on continuous positive airway pressure (CPAP), which was quickly transitioned to bi-level PAP for hypoventilation and titrated to 24/10 cm H2O. Increasing PAP showed improvement in hypoventilation, but significant worsening of hypoxia requiring 6 liters/min oxygen. For this reason, and the emergence of central hypopneas, the patient was prescribed fixed CPAP at 10 cm H2O with 4 liters/min nocturnal oxygen. He displayed strong CPAP adherence while monitored with home oximetry and underwent repeat titration PSGs. Final titration PSG showed resolution of both hypercapnia and hypoxia. He was continued on CPAP at 10cm H2O without supplemental oxygen. Conclusion Comorbid obesity and sleep-related hypoventilation are increasingly encountered in HFrEF. Elevated PAP administration aimed at correcting hypoventilation during PSG may increase intrathoracic pressure leading to increased right ventricular (RV) afterload and compromised cardiac output. Additionally, elevated RV afterload can result in right-to-left shunting and refractory hypoxia, as suggested by our case. Furthermore, it is unclear whether chronic hypercapnia in OHS protects against CSA of HF or increases susceptibility to CSA during non-invasive ventilation. While PAP provides respiratory benefits, it must be used cautiously in patients with advanced HF. Regular CPAP use in patients with OHS has previously shown improvement in hypoxia and hypercapnia after six weeks of adherent treatment. Individualized therapy, guided by repeat PSG and home nocturnal oximetry or capnography, is essential for optimal management of this complex, high-risk population. Support (if any)