No hospitalization benefit with noninvasive ventilation in obesity hypoventilation syndrome

Noninvasive ventilation and lifestyle modification yielded similar long-term hospitalization rates in patients with obesity hypoventilation syndrome, researchers reported at the virtual European Respiratory Society International Congress.

“Obesity hypoventilation syndrome is typically treated with positive forward pressure in the forms of continuous positive forward pressure in noninvasive ventilation. CPAP and noninvasive ventilation have been showed to have similar medium-term and long-term outcomes in three randomized controlled trials of obesity hypoventilation syndrome patients with severe obstructive sleep apnea,” Maria A. Sanchez-Quiroga, MD, of the respiratory department at Virgen del Rocio University Hospital, Plasencia, Spain, said during her presentation. “In contrast, there [has] been only one medium-term randomized controlled trial comparing noninvasive ventilation to lifestyle changes in patients with obesity hypoventilation syndrome without severe obstructive sleep apnea.”

Researchers conducted an open-label, multicenter, parallel-group clinical trial to assess the efficacy of noninvasive ventilation in 98 stable ambulatory patients with untreated obesity hypoventilation syndrome (OHS) without severe OSA and an apnea-hypopnea index of 30 or less events per hour.
Patients were randomly assigned to noninvasive ventilation (n = 49; mean age, 67 years; 77.1% women) or lifestyle modification (n = 49; mean age, 68.5 years; 83.3% women). The primary endpoint was hospitalization days per year.

During the median follow-up of 4.28 years, patients in the lifestyle modification group had a mean hospitalization of 2.6 days per year compared with 2.71 days per year in the noninvasive ventilation group (adjusted RR = 1.07; 95% CI, 0.44-2.59; P = .882).

Adverse events were similar in both groups, with cardiovascular events occurring in 23% of the lifestyle modification group vs. 21% of the noninvasive ventilation group (HR = 0.96; 95% CI, 0.4-2.3; P = .927). Researchers observed similar adverse event rates in a per-protocol analysis of 48 patients from each arm (RR = 1.21; 95% CI, 0.43-3.41; P = .717).

Nine patients in both treatment arms died during the trial (aHR = 1.07; 95% CI, 0.41-2.82; P = .893). Similar results were observed in the per-protocol analysis (RR = 1.38; 95% CI, 0.50-3.79; P = .529).

“According to these results, we can conclude that in stable ambulatory patients with obesity hypoventilation syndrome without severe obstructive sleep apnea, noninvasive ventilation and lifestyle modification have similar long-term hospitalization days per year, incidence of cardiovascular events and mortality,” Sanchez-Quiroga said. “Larger studies are necessary to better determine the long-term benefit of noninvasive ventilation in this group of patients and more intensive programs aimed to improving noninvasive ventilation evidence may lead to better outcomes.”