NIV and CPAP Similarly Improve LV Dysfunction in Obesity Hypoventilation Syndrome With OSA

Treatment with noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP) during a  3-year period provided similar improvements in pulmonary hypertension and left ventricular (LV) diastolic dysfunction in patients with obesity hypoventilation syndrome (OHS) and concomitant severe obstructive sleep apnea (OSA), according to study results published in the American Journal of Respiratory and Critical Care Medicine.

Patients with suspected OHS and OSA (age range, 15-80 years) were recruited from 16 tertiary care hospitals in Spain. The open-label trial (ClinicalTrials.gov Identifier: NCT01405976) initially randomly assigned patients to receive either NIV or CPAP, or to a control group (ie, lifestyle changes) for 2 months. After this period, patients in the control group were randomly assigned again to either NIV or CPAP. During the entire study period, a total of 102 patients were treated with CPAP and 94 were treated with NIV. Ambulatory patients with OHS and severe OSA underwent transthoracic 2-dimensional and Doppler echocardiography at baseline and each year for 3 sequential years. 

From baseline to 3-year follow-up, significant reductions in systolic pulmonary artery pressure were observed in the CPAP (40.5±1.47 mm Hg to 35.3±1.33 mm Hg, respectively) and NIV (41.5±1.56 mm Hg to 35.5±1.42 mm Hg, respectively) groups (P <.0001 for longitudinal intragroup changes in both treatment arms). Both groups performed equally well in terms of improving pulmonary hypertension. 

Treatment with NIV and CPAP both improved LV diastolic dysfunction (E/A ratio; adjusted P =.013 for longitudinal intragroup changes in both treatment arms), and both therapies were associated with reduced left atrial diameter (adjusted P =.023 for longitudinal intragroup changes in both treatment arms). Respiratory function and dyspnea were also improved with both therapies.

Despite initially randomly assigning patients to a control group, the analysis did not focus on an untreated control group, representing a potential study limitation.

Findings from this study suggest “that echocardiograms may offer valuable clinical information in the management of patients with OHS and severe OSA treated with PAP therapy.”

Reference

Masa JF, Mokhlesi B, Benítez I, et al; on behalf of the Spanish Sleep Network. Echocardiographic changes with positive airway pressure therapy in obesity hypoventilation syndrome: long-term Pickwick Randomized Controlled Trial [published online November 4, 2019]. Am J Respir Crit Care Med. doi:10.1164/rccm.201906-1122OC