CPAP is Better Treatment for OSA than AOP (Atrial Overdrive Pacing)

December 15th 2005

CPAP nasal mask

A comparison has been made between the standard CPAP therapy and a new treatment called AOP. The research was published in the New England Journal of Medicine (NEJM) on December 15th. The new findings indicated that CPAP is still a better therapy than AOP for obstructive sleep apnea (OSA).

Two years ago French physicians said AOP (atrial overdrive pacing) had produced significant improvement with some people with OSA. The new research compared results of 16 patients and found AOP had no significant effect.

All 16 people in the Greek trial already had a pacemaker. The pacemakers were programmed to produce 15 beats more per minute than normal in half the group. The other half kept the pacemaker programmed to the normal beats per minute, but used CPAP (Constant Positive Air Pressure) therapy. After one month the groups switched therapies.

"During AOP, no significant changes were observed in any of the respiratory variables measured," according to the researchers. The CPAP group got substantial improvement in sleep quality. The improvements were measured in two ways. The researchers looked at the sleep index that shows the incidence of apnea events. They also interviewed the patients about their daytime sleepiness.

An earlier study initially backed up the French study, but now casts doubt on it. Doctors at Baylor College of Medicine initially studied 13 patients and found AOP therapy significantly helped two of them. Since then they have enrolled more patients and “they did not respond”.

The AOP treatment could benefit patients with CSA (Central Sleep Apnea). This is a condition where the brain forgets to breath. Typically this happens to people as they age. The Greek research concerned itself with people with OSA (obstructive sleep apnea). This occurs when the airway is obstructed, usually because the throat relaxes when asleep.

Sleep apnea increases the risk of stroke and heart attack. Sleep apnea can also cause an increase in early morning blood pressure. Most people do not realize they have sleep apnea because they are asleep when it occurs. The first sign to look for is a loud snore.

Earlier research shows that CPAP therapy can help prevent heart failure. Research at UCLA found that as we age we lose brain stem cells. They found that this is the primary reason why the elderly develop CSA. There is a timed CPAP therapy that is developed for CSA.

The Greek trial was conducted by doctors at Heraklion University Hospital in Crete.