• Sleep Disorders
• Pulmonary Clinical Trials
• Hypertensive Disease

• Sleep Disorders
• Pulmonary Clinical Trials
• Pulmonary & Critical Care
• Hypertensive Disease

In a randomized clinical trial conducted in Spain, blood pressure (BP) in patients with resistant hypertension (RH) and obstructive sleep apnea (OSA) was significantly and clinically reduced following treatment with continuous positive airway pressure (CPAP). In those patients with good adherence to CPAP therapy, a significant percentage recovered their normal nocturnal dipper pattern and/or reversed their riser pattern. Miguel Ángel Martínez-García, MD, PhD, University and Polytechnic La Fe Hospital, Valencia, Spain, presented the results of the HIPARCO study (Hipertensión Arterial Resistente Control con CPAP).

The objective of this multicenter study was to evaluate the effect of CPAP treatment on the BP levels and nocturnal BP pattern in patients with OSA and RH. Patients with RH and confirmed OSA were randomly assigned to usual medical therapy (n=96) or medical therapy plus tritated fixed CPAP pressure (n=98) for 12 weeks. Patients with 24-hour BP >130/85 mm Hg (determined by ambulatory blood pressure monitoring [ABPM]), an apnea-hypopnea index >15, and with at least an 80% adherence to antihypertensive drug treatment were included in the study. The prevalence of OSA was 82.7% in this population. Patients were monitored at 2, 4, 8, and 12 weeks for CPAP and antihypertensive drug adherence, changes in body mass index (BMI), and new cardiovascular (CV) events. At the 12-week visit, patients underwent a second 24-hour ABPM. All randomized patients independent of their use or not of CPAP were included in the intention-to-treat (ITT) analysis and those patients with a good adherence to CPAP (≥4 hours of CPAP; 68% of randomized patients) use were included in the per protocol (PP) analysis.

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Demographics and baseline characteristics were similar in both treatment groups. Mean BMI was 34.1±5.4 kg/m²; mean number of antihypertensive drug used was 3.8±0.9; 21.4% of participants had past CV events; mean 24-hour BP was 144.2±12.5/83.0±10.5 mm Hg. More than 70% of patients had a nondipper (42.8%) or a riser nocturnal (31.4%) BP pattern. Almost 95% of the patients were on diuretics.

In the ITT analysis, the use of CPAP significantly reduced diastolic (p=0.005) and mean BP (p=0.016) compared with the control group and was associated with a near-significant reduction in 24-hour systolic BP (p=0.09). The reductions (about 3 mm Hg), were clinically relevant. In the PP analysis (only those patients with good CPAP compliance), CPAP use significantly decreased systolic BP, diastolic BP, and mean BP by 4 to 5 mm Hg (p=0.01, p=0.001, and p=0.001, respectively).

The decreases in BP levels were more pronounced during the night especially in those patients with better tolerance to CPAP.

The probability of recovering the dipper pattern and reversing the riser pattern was significantly greater (p≤0.03) in both the ITT and PP analysis in those patients allocated to the CPAP arm. Moreover there was a positive and linear relationship between the number of hours of CPAP use and the decrease in 24-hour BP values, both BP diurnal and nocturnal values. The presence or absence of daytime hypersomnolence, sex, age, years from RH diagnosis and BMI had no impact on treatment effectiveness.

Prof. Martínez-García would like to see future long-term studies that analyze the effect of CPAP on the incidence of CV events or death and BP treatment in these patients with RH and OSA.

• © 2013 MD Conference Express®