How to Diagnose Sleep-disordered Breathing

A new study found that SleepMinder, a contactless bedside nocturnal respiratory monitor, could be a key device in diagnosing sleep-disordered breathing (SDB), the most common co-morbidity seen in heart failure (HF) patients. ResMed, the manufacturer of SleepMinder, revealed the research findings during the ESC Congress 2014 in Barcelona, Spain.

SDB is traditionally diagnosed by computing the Apnea-Hypopnea Index (AHI) based on a single-night assessment using polysomnography (PSG) in a specialist sleep center or hospital. However, due to volume load changes, AHI tends to be highly variable in HF patients over time.

So the study examined how collecting data for two weeks via the SleepMinder (which was placed beside each patient’s bed) fares against this standard procedure. As it turns out, mean AHI assessment conducted over a two-week period yields more accurate results.

Based on the data researchers gathered, mean AHI consistently appeared to be above the treatment threshold (AHI ≥15) in 57 percent of patients. This figure increased to 74 percent at the end of the follow-up, which lasted 12 months.

Of the 15 million HF patients in Europe, 50 to 75 percent suffer from SDB. However, cardiologists often do not recognize SDB and thus the diagnosis is missed in most cases. If undiagnosed and untreated, SDB could result hospitalization, a lower quality of life and even death.

“This study showed that, by using a device that can gather longer-term data, we can offer a means of diagnosis that is both practical for patients, doctors, and health services and may well be more accurate than existing techniques that require inpatient care,” said Martin Cowie, co-author of the study and professor of cardiology at Royal Brompton Hospital in London.