BACKGROUND: Obstructive sleep apnea (OSA) has been established as a contributing factor in multiple chronic cardiovascular diseases. These effects include difficult to treat hypertension, aggravating coronary artery disease, fatigue, atrial fibrillation and heart failure among others. In North America, the average wait time for a sleep lab study is 3-6 months. Unfortunately patients that would benefit from OSA treatment are difficult to manage during this time and their conditions can worsen while waiting for a sleep lab study. Accurate and timely diagnosis of OSA with a home sleep screening device (Nox) can help in management of these patients and their conditions.
METHODS AND RESULTS: 30 patients from a single center cardiology practice were screened for OSA using the NOX device. The Nox sleep monitor is made by Nox Medical and is outfitted with a nasal cannula and oxygen saturation monitor to provide sleep diagnostics. A cardiac Holter monitor is also placed to corroborate this data throughout the night. The data is then downloaded the morning after and a report is generated with apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) values. The patients are then classified into mild, moderate, severe or ruled out of having OSA. All patients screened positively for OSA were immediately booked for a full sleep lab study and the data was collected from their sleep lab reports. Of the 30 patients screened, 3 were evaluated as having none-mild sleep apnea whereas the remaining 27 were evaluated as having moderate to severe sleep apnea. These patients were further assessed with a full sleep lab study and were confirmed to have moderate to severe sleep apnea. Their sleep screening assessments allowed for sooner sleep study bookings (within 2 months) and earlier intervention. On follow-up these patients were easier to manage as their chronic cardiovascular disease processes lessened.
CONCLUSION: The ability to accurately, confidently and rapidly screen patients for sleep apnea with a home sleep monitoring device is beneficial in the management of OSA patients. Having this data allows for full sleep lab studies to be booked sooner and to confirm patients at high risk for OSA. The accuracy of the Nox device has been proven in comparison to full sleep lab studies. Treatment can be initiated earlier in these patients in the form of mineralocorticoid receptor antagonists such as Spironolactone which have been shown to be effective in blood pressure control of OSA patients.