Overview of the CRESCENT Trial
Comparing treatments for Sleep Apnea and Hypertension
PULSE Issue 43 | July 2024
Hypertension is a leading risk factor for heart disease and stroke, making blood pressure control critically important. Obstructive Sleep Apnea (OSA), which affects 1 in 3 Singapore residents, is a significant and often undiagnosed cause of hypertension. Current medical opinions recommend screening for and treating OSA in patients with hypertension to help manage their blood pressure. Continuous Positive Airway Pressure (CPAP) is the standard treatment for OSA, delivering air through a mask to keep the airway open during sleep. However, many patients either refuse CPAP or find it difficult to use consistently.
What is a Mandibular Advancement Device?
A Mandibular Advancement Device (MAD) is a small mouth mouthpiece worn during sleep that moves the lower jaw forward to keep the airway open. It is an alternative to CPAP for treating OSA. However, it's not yet clear if using a MAD can reduce blood pressure in patients with OSA.
About the CRESCENT Trial
The CRESCENT trial, led by Prof Ronald Lee Chi-Hang, Senior Consultant, Department of Cardiology, NUHCS, aimed to compare the effectiveness of MAD versus CPAP in lowering blood pressure in patients with OSA and hypertension. The goal was to show that MAD is not worse than CPAP in this regard. A total of 220 Singapore residents were recruited between 2019 and 2022 and were randomly assigned to receive either the MAD or CPAP as treatment for OSA. Both the MAD and CPAP groups were supported and guided by a team of medical experts in OSA treatment.
Results
After more than four years of dedication and commitment, the results of the CRESCENT trial were presented at the American College of Cardiology's Annual Scientific Session in Atlanta as late-breaking clinical research in early April 2024. At the same time, the trial findings were published online in the Journal of the American College of Cardiology, a prestigious cardiovascular journal. The main findings were that both the MAD and CPAP were effective in reducing the classic sleep apnea symptom of excessive daytime sleepiness. Usage of the MAD device was higher than with the CPAP device, with 56% in the MAD group using it for at least six hours per night, compared to 23% in the CPAP group. Importantly, a 2.5mmHg reduction in 24-hour mean arterial blood pressure was observed in the MAD group at the six-month follow-up, while no change in blood pressure was observed in the CPAP group. Overall, we found that MAD is not worse than CPAP in reducing blood pressure in patients with OSA and hypertension.
Key Message for Singapore Residents
OSA is a common medical condition, particularly in individuals who are overweight or obese, snore during sleep, and feel sleepy during the daytime despite adequate sleep duration. While CPAP is often offered as the first-line treatment, MAD is an approved alternative if you find CPAP uncomfortable or simply want to try a different OSA treatment.
