New research out of Spain shows that stroke patients with obstructive sleep apnea (OSA) who undergo treatment with continuous positive airway pressure (CPAP) after their stroke may significantly reduce their risk of death.

The research appears the July 1 issue of the American Journal of Respiratory and Critical Care Medicine.

"Our results suggest that patients with ischemic stroke and moderate to severe OSA showed an increased mortality risk," wrote lead author, Miguel Angel Martínez-García, MD, of Requena General Hospital in Valencia, Spain. "CPAP treatment, although tolerated by only a small percentage of patients, is associated with a reduction in this excess risk and achieves a mortality [rate] similar to patients without OSA or with mild disease."

The study recruited 166 consecutive patients who had an ischemic stroke and subsequently were diagnosed with sleep apnea. Participants had a mean age of 73.3 years. CPAP treatment was offered to the 96 patients who had an apnea-hypopnea index (AHI) over 20. Each patient was followed for 5 years and was evaluated for general status, new cardiovascular events, CPAP adherence, and death.

At the conclusion of the 5-year follow-up period, 48.8% of the original study group had died. Only 28 of the original 96 were considered to be fully compliant with CPAP treatment. After adjusting for 13 potentially confounding variables, the researchers found that those with moderate to severe OSA who had not complied with CPAP treatment had nearly 1.6 times the risk of death compared to patients who tolerated CPAP. Those with moderate-to-severe disease who had tolerated CPAP had similar risk of death as did patients without sleep apnea or mild disease.

"Our results suggest that moderate to severe OSA in patients with stroke has an unfavorable effect on long-term mortality. CPAP treatment is associated with a reduction in this excess risk," wrote Martínez-García.

"Patients who did not tolerate CPAP might have a special profile; [they] may have poor adherence to other types of treatment, including treatment of cardiovascular prevention, which would carry with it a higher risk of stroke," said Martínez-García in an announcement about the study. "However, the variables that measure the adherence of all the treatments in these patients are very difficult to analyze because patients often take many medications. This is a limitation of our study."