Effects of CPAP on Central and Peripheral Blood Pressure in Patients with Uncontrolled Hypertension and OSA: The MORPHEOS Trial

Previous studies evaluating the effect of continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA) on blood pressure (BP) showed variable results. Moreover, several studies recruited patients with normal or controlled BP, and compliance to antihypertensive drugs was not monitored. In addition, very few studies investigated central BP in this scenario. To evaluate whether OSA treatment is able to reduce central and peripheral BP in patients with uncontrolled hypertension (HTN) despite well documented use of anti-hypertensive treatment. The MORPHEOS is a multicenter, randomized controlled trial designed to evaluate the effects of CPAP or placebo (nasal dilator strips-NDS) for 6-months in patients with moderate-to-severe OSA and uncontrolled HTN on office BP, ambulatory BP monitoring (ABPM) and central BP (co-primary endpoints). Uncontrolled HTN was defined by ≥1 abnormal parameter in ABPM after 1-month of pill count and ≥80% adherence to medication. Pill count, adherence to CPAP or NDS and office BP was determined once a week in the first month and monthly thereafter. A total of 123 patients completed the study (NDS: n=64, CPAP: n=59). The two groups were similar at baseline. Adherence to NDS (≥80%) and CPAP (≥4h/night) were 98.3% and 81.7%, respectively. As compared to NDS, office systolic BP (Δ=-10±16mmHg, p<0.001) and diastolic BP (Δ=-7±12mmHg, p=0.001) were reduced significantly in the CPAP group. Despite the BP lowering effect of CPAP did not reach statistical differences for ABPM parameters, the rate of 24-h ABPM control (<130X80mmHg) was higher in the CPAP than in the NDS group (40.7 vs 20%; p=0.024). Central diastolic BP reduced significantly (Δ=-6±9mmHg; adjusted p=0.029). CPAP improves the rates of BP control in patients with OSA and uncontrolled HTN under regular use of medications. Clinical trial registration available at www. gov, ID: NCT02270658.