Effect of Continuous Positive Airway Pressure (CPAP) Treatment in the Control of Refractory Hypertension

This study has been completed.
Information provided by (Responsible Party):
Miguel angel Martinez Garcia, Sociedad Española de Neumología y Cirugía Torácica
ClinicalTrials.gov Identifier:
First received: February 4, 2008
Last updated: February 28, 2012
Last verified: February 2012

The working hypothesis for the present study is that treatment with CPAP in patients with an sleep apnea (IAH>15) and AHT-r is capable of producing significant reductions in blood-pressure levels.

This hypothesis is supported by four proven findings:

  1. -sleep apnea is an independent risk factor for arterial hypertension (1).
  2. -The greater the number of RSD, the greater the loss of control over blood-pressure levels (1).
  3. -The prevalence of sleep apnea in patients with AHT refractory to treatment is very high (11,12).
  4. -Treatment of patients with sleep apnea and AHT-r with CPAP succeeds in significantly reducing blood-pressure levels in the only (small-scale) studies undertaken to date (14,15).


Main objective:

To evaluate the effect of treatment with CPAP on blood-pressure levels in patients with AHT refractory to medical treatment.

Secondary objectives:

  • To evaluate the effect of treatment with CPAP on the various elements assessed in BP (systolic/diastolic; daytime/nighttime, etc) and the circadian profile (dipper/non-dipper/raiser patterns; variability and homogeneity of blood-pressure levels, etc) obtained during a 24-hour out-patient study (AMPA).
  • To analyze the related variables or subgroups of patients most affected by treatment with CPAP.
  • To evaluate the effect of CPAP on the levels of some of the biological variables involved in the pathogenesis of AHT-r (renin, angiotensin, aldosterone, atrial natriuretic factor, etc).

Condition Intervention
Sleep Apnea
Device: CPAP

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effect of CPAP Treatment in the Control of Refractory Hypertension

Resource links provided by NLM:

Further study details as provided by Sociedad Española de Neumología y Cirugía Torácica:

Primary Outcome Measures:
  • Effect on blood pressure levels [ Time Frame: Before and six months after CPAP treatment ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Effect on night blood pressure pattern [ Time Frame: Befor and six month after CPAP treatment ] [ Designated as safety issue: Yes ]

Enrollment: 210
Study Start Date: June 2008
Study Completion Date: February 2012
Primary Completion Date: December 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
No Intervention: B
Group B. Only Usual Control
Experimental: A
Group A: Cpap treatment plus Usual control
Device: CPAP
Pressure device on airway to maintain it open
Other Name: Continuous positive airway pressure

Detailed Description:

OBJECTIVE. To evaluate the effect of continuous positive airway pressure (CPAP) treatment on the blood-pressure (BP) levels of patients with refractory arterial hypertension (AHT-r).

METHODS: Multicenter randomized study with parallel groups and blind final evaluation.

Patients will be recruited from AHT, nephrology or internal medicine outpatient clinics and will satisfy the criteria for AHT-r (patients requiring 3 anti-AHT drugs at recommended doses to maintain their blood-pressure levels within AMPA [24-hours ambulatory monitoring of blood pressure values) excluding those forms of secondary AHT and those patients with incapacitating hypersomnia that need immediate treatment. In all, 210 patients will be included (105 per arm for intention to treat analysis) in accordance with the calculation of the sample size needed including drop-outs to evaluate a clinically significant minimum drop of 4-5 mmHg in the mean BP and the number of centers (21 centers; 10 patients per center). They will all be subjected to a complete clinical history, an AMPA study, a blood test (with serum retained for a later determination of biological mediators) and a sleep study. Those patients with an AHI>15 will be randomized to receive CPAP vs habitual control. The treatment will last 3 months. The same variables that were measured before the randomization will be analyzed again for the purposes of comparison. The comparison of results will be undertaken on the basis of an intention-to-treat and per-protocol analyses based on adherence to CPAP treatment at different cutoff of hours /day by means of an ANOVA two-way analysis (one of them being time).


Ages Eligible for Study:   18 Years to 75 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  1. Patients aged 18-75 with a diagnosis of primary AHT-r and an AHI ≥15.
  2. Signature indicating informed consent.

Exclusion Criteria:

  1. Those patients with, in the opinion of the researcher, incapacitating hypersomnia will be excluded (to avoid the ethical problems associated with not treating a symptomatic sleep apnea patient).
  2. Patients with risky professions or work involving dangerous goods.
  3. Pregnancy.
  4. The regular use of psychotropic drugs that could significantly modify the results of the sleep studies, or previous alcoholism (more than 100 gr of alcohol/day).
  5. Patients previously treated with CPAP.
  6. Record of poor compliance with anti-hypertensive treatment.
  7. AHT secondary to cardiac insufficiency, valvulopathy, renal or endocrinological causes, cor pulmonale or the consumption of oral corticoids, or any other known cause.
  8. Patients who have suffered from a cardiovascular event in the month prior to inclusion in the study, or patients who were unstable at the time of their inclusion in the study.
  9. Known renal insufficiency with a concentration of creatinine greater than 1.5 mg/dl
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00616265

General Hospital of Requena
Valencia, Spain, 42340
Sponsors and Collaborators
Sociedad Española de Neumología y Cirugía Torácica
Principal Investigator: Miguel Angel Martínez-Garcia, MD Sociedad Española de Neumología y Cirugía Torácica
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Miguel angel Martinez Garcia, MD, Sociedad Española de Neumología y Cirugía Torácica
ClinicalTrials.gov Identifier: NCT00616265     History of Changes
Other Study ID Numbers: Prot-740  Prot-740 SEPAR  SEPAR-90 
Study First Received: February 4, 2008
Last Updated: February 28, 2012
Health Authority: Spain: Ethics Committee

Keywords provided by Sociedad Española de Neumología y Cirugía Torácica:
Sleep apnea
Refractory Hypertension
Difficult-to-treat hypertension

Additional relevant MeSH terms:
Cardiovascular Diseases
Vascular Diseases

ClinicalTrials.gov processed this record on May 26, 2016