Effects of Continuous Positive Airway Pressure (CPAP) in Patients With Resistant Hypertension and Obstructive Sleep Apnea (OSA)

Obstructive Sleep Apnea Clinical Trial

Official title:

Effects of Continuous Positive Airway Pressure in Patients With Resistant Hypertension and Obstructive Sleep Apnea

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00812695
• Other study ID #: RH-OSA
• Status: Completed
• Phase: Phase 3
• First received: December 19, 2008
• Last updated: November 21, 2011
• Start date: October 2008
• Est. completion date: March 2011

Study information

• Verified date: November 2011
• Source: University of Sao Paulo
• Contact: n/a
• Is FDA regulated: No
• Health authority: Brazil: National Committee of Ethics in Research
• Study type: Interventional

Clinical Trial Summary

Obstructive sleep apnea (OSA) is an important cause of refractory hypertension but the impact of treatment with continuous positive airway pressure (CPAP) is not completely understood. The aim of this project is to study the effects of CPAP on blood pressure control and its influences on cardiac remodeling and arterial stiffness in patients with refractory hypertension and moderate or severe OSA.

Description:

Study design Interventional, open-label, randomized.

Patients selection

Fifty refractory hypertensive patients with moderate-to-severe OSA, aged between 30 to 65 years old will be recruited from the outpatient clinics of the Heart Institute by the hospital staff.

Refractory hypertension will be defined as usually: blood pressure higher than or equal to 140x90 mmHg after a regimen of three drugs, including a diuretic for a minimum of 3 months. Initial evaluation will consist on ambulatory blood pressure measurement for 24 hours and a detailed clinical examination. Moderate to severe OSA will be defined as an apnea-hypopnea index > 15 evens per hour, after an overnight polysomnography.

Exclusion criteria include BMI >40 kg/m2; diabetes mellitus; aortic, heart and valve diseases; renal failure; other identifiable causes of hypertension, no adherence, use of cocaine, amphetamines, other illicit drugs, sympathomimetics (decongestants, anorectics), oral contraceptive hormones, nonsteroidal anti-inflammatory drugs.

Refractory hypertension Secondary causes of hypertension will be excluded using usual procedures from the Hypertension Unit.

Polysomnography All participants will be submitted to standard overnight polysomnography (EMBLA - Flagra hf. Medical Devices, Reykjavik, Iceland). The apnea-hypopnea index will be calculated as the total number of respiratory events (apneas plus hypopneas) per hour of sleep.

Apnea will be defined as an air flow cessation greater than 10 seconds and hypopnea as a reduction grater than 50% with oxygen saturation fall grater than 4% or arousal.

After recruitment, patients will be instructed about CPAP working by an experimented professional and another polysomnography will be done to adjust pressures. Hour counter will be used to check the adherence to CPAP.

Intervention Patients will be divided in two groups: medical treatment plus CPAP or medical treatment alone for 6 months without drug dose changing.

Twenty-four hour blood pressure monitoring Twenty-four hour blood pressure monitoring (system SpaceLabs 90207) will be used in all patients in the beginning and at the end of the study.

Arterial Stiffness Carotid-femoral arterial stiffness will be determined by Complior.

Echocardiography Echocardiography will be performed by using a commercially available machine.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 40
• Est. completion date: March 2011
• Est. primary completion date: March 2011
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 30 Years to 65 Years

Eligibility

Inclusion Criteria:

• Refractory hypertensive patients with moderate-to-severe OSA, aged between 30 to 65 years old.

Exclusion Criteria:

• Aortic, heart and valve diseases

• Renal failure

• Other identifiable causes of hypertension, no adherence, use of cocaine, amphetamines, other illicit drugs, sympathomimetics (decongestants, anorectics), oral contraceptive hormones, nonsteroidal anti-inflammatory drugs.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Apnea
• Hypertension
• Obstructive Sleep Apnea
• Refractory Hypertension
• Sleep Apnea Syndromes
• Sleep Apnea, Obstructive

Intervention

Device:
• CPAP
Gold standard treatment for Obstructive sleep apnea

Locations

Country	Name	City	State
Brazil	Heart Institute (InCor)	Sao Paulo

Sponsors (1)

Lead Sponsor	Collaborator
University of Sao Paulo

Country where clinical trial is conducted

Brazil, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Ambulatory blood pressure monitoring		Change from Baseline in Blood Pressure at 6 months	Yes
Secondary	Change from Baseline in Arterial stiffness at 6 months		baseline and 6 months	Yes
Secondary	change from baseline in heart remodeling at 6 months		baseline and 6 months	Yes