Echocardiographic Changes with Positive Airway Pressure Therapy in Obesity Hypoventilation Syndrome. Long-Term Pickwick Randomized Controlled Clinical Trial

Obesity hypoventilation syndrome (OHS) has been associated with cardiac dysfunction. However, randomized trials assessing the impact of long-term noninvasive ventilation (NIV) or continuous positive airway pressure (CPAP) on cardiac structure and function assessed by echocardiography are lacking. In a prespecified secondary analysis of the largest multicenter randomized controlled trial of OHS (Pickwick Project; = 221 patients with OHS and coexistent severe obstructive sleep apnea), we compared the effectiveness of three years of NIV and CPAP on structural and functional echocardiographic changes. At baseline and annually during three sequential years, patients underwent transthoracic two-dimensional and Doppler echocardiography. Echocardiographers at each site were blinded to the treatment allocation. Statistical analysis was performed using a linear mixed-effects model with a treatment group and repeated measures interaction to determine the differential effect between CPAP and NIV. A total of 196 patients were analyzed: 102 were treated with CPAP and 94 were treated with NIV. Systolic pulmonary artery pressure decreased from 40.5 ± 1.47 mm Hg at baseline to 35.3 ± 1.33 mm Hg at three years with CPAP, and from 41.5 ± 1.56 mm Hg to 35.5 ± 1.42 with NIV (