CPAP Therapy in Patients With Heart Failure and Obstructive Sleep Apnea. (PET-OSA)

May 28, 2018 updated by: Rob Beanlands, Ottawa Heart Institute Research Corporation

Effects of Continuous Positive Airway Pressure Therapy on Myocardial Energetics and Sympathetic Nerve Function in Patients With Heart Failure and Obstructive Sleep Apnea.

Heart failure affects approximately 5-6 million North Americans and is increasing in prevalence. Sleep-related disorders, such as obstructive sleep apnea (OSA) often coexist (11-37% incidence) with heart failure. OSA is the repeated temporary interruption of breathing during sleep and occurs when the air passages in the upper respiratory tract become blocked during sleep. OSA adversely affects the cardiovascular system resulting in hypoxia (decrease in oxygen supply), which decreases the oxygen supply to the heart. Patients with OSA are treated with continuous positive airway pressure (CPAP). It has also been shown that CPAP reduces angina during sleep, minimizes sympathetic nervous system (SNS) activation and improves left ventricular (LV) function, although the mechanism of action is not clear. Carbon-11 acetate PET imaging allows for the assessment of how the heart works and how efficiently the heart uses oxygen in certain circumstances. Carbon-11 hydroxyephedrine (HED) measures cardiac nervous system activity, which may have an effect on heart rate. The study will evaluate the term effects of continuous positive airway pressure (CPAP), a common treatment for patients with OSA, on the heart's efficiency or ability to work and its effect on the nervous system activity of the heart. Two patient groups will be evaluated 1.) patients with congestive heart failure and obstructive sleep apnea will be randomized to early or late CPAP to address the primary hypothesis of the study and 2.) patients with congestive heart failure only (matched control group). Both the primary randomized study group and secondary study group will be evaluated using [11C]acetate PET, [11C]HED PET and echocardiography. Measurements will be obtained at baseline, 1 week (where possible) and 6-8 weeks.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

OSA and heart failure (HF) are states of increased afterload, metabolic demand and sympathetic nervous system(SNS) activation. In patients with OSA and HF, CPAP initially may reduce LV stroke volume(SV) but subsequently improves LV function. This may relate to an early beneficial effect on myocardial energetics through early reduction in metabolic demand that subsequently leads to improved efficiency of LV contraction. However, it is not clear whether CPAP favourably affects cardiac energetics. Any such benefit may also relate to reduced SNS activation with CPAP therapy. However its effect on myocardial SN function is also not well studied. We propose to evaluate the temporal effect of CPAP on daytime 1) oxidative metabolism; 2) the WMI as an estimate of mechanical efficiency; 3) myocardial SN pre-synaptic function; and 4) HR variability in patients with OSA and HF. We will also determine whether these parameters are altered compared to a group of patients with HF without OSA. In conjunction with echocardiographic measures of LV stroke work, PET derived [11C]acetate kinetics will be used as a measure of oxidative metabolism, to determine the work metabolic index (WMI). [11C]HED retention will be used to measure cardiac SN pre-synaptic function.

HYPOTHESES

Primary Hypotheses:

In patients with chronic stable HF and OSA, 6-8 weeks' of CPAP demonstrates:

  1. beneficial effects on daytime myocardial metabolism leading to a reduction in the rate of oxidative metabolism as measured by [11C]acetate kinetics using PET imaging;
  2. improvement in energy transduction from oxidative metabolism to stroke work as measured by an increase in the daytime work-metabolic index.

Secondary Hypotheses:

In patients with chronic stable heart failure and OSA,

  1. CPAP leads to an early (1 week'') reduction in daytime oxidative metabolism that precedes the improvement in work-metabolic index, indicating an early energy sparing effect;
  2. CPAP leads to i) an increase in daytime myocardial SN pre-synaptic function as measured by increased [11C]HED retention on PET imaging, and ii) a parallel decrease in sympathetic and increase in vagal modulation of sino-atrial discharge (i.e. heart rate (HR) variability)
  3. there is impaired daytime myocardial oxidative metabolism, work-metabolic index, and myocardial sympathetic nerve function compared to patients with heart failure without OSA.

'original protocol indicated 1 month follow up but was changed to 6-8 weeks in order to accommodate patient logistics and imaging centre scheduling.

''Logistics did not permit all patients to complete 1 week scan.

Study Type

Interventional

Enrollment (Actual)

67

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Ottawa, Ontario, Canada, K1Y 4W7
        • University of Ottawa Heart Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • systolic LV dysfunction (LVEF<40%; by echocardiography, radionuclide or contrast ventriculography)
  • symptoms of HF: NYHA Class II to III
  • stable condition with optimally tolerated medical therapy, unchanged for > 4 weeks
  • Obstructive sleep apnea (OSA) diagnosed on nocturnal polysomnogram with an apnea/hypopnea index (AHI) >15 events/hr and a predominantly obstructive pattern(more than 80% of events being obstructive in nature)OR
  • no OSA: defined as AHI<5 (control subjects) will be matched with the OSA group for gender, age + 5 years, ejection fraction (EF) +5%, drug therapy and etiology of HF (ischemic or non-ischemic)
  • willingness to receive CPAP therapy
  • informed consent

Exclusion Criteria:

  • unstable angina or recent myocardial infarction (MI) (<4 weeks prior)
  • severe valvular dysfunction
  • requirement for revascularization
  • a permanent pacemaker
  • atrial fibrillation
  • significant ventricular arrhythmia or sinus node dysfunction
  • life expectancy less than 1 year due to other co-morbidity
  • significant restrictive and obstructive lung disease
  • concomitant treatment or use of: tricyclic antidepressants, cocaine or drugs which may alter catecholamine uptake; or hypnotic, benzodiazepine, selective serotonin reuptake inhibitors(SSRI), neuroleptic, narcotic or other medications which may alter sleep or sleep-disordered breathing
  • central sleep apnea
  • other primary sleep disorder (i.e. periodic limb movement with arousal >5 events/hr, narcolepsy, rapid eye movement (REM) behaviour disorder)
  • requiring supplemental oxygen therapy at night
  • debilitating daytime somnolence (indicating clear-cut indication for CPAP therapy)
  • a previous cardiac transplant
  • a large transmural scar defined on previous perfusion imaging(severe resting perfusion defect (<50% uptake) occupying >25% of the LV)148-150
  • age < 18 years
  • pregnant or breast-feeding

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: 1
Heart Failure-OSA Group, randomized to early CPAP
Other: Positron Emission Tomography
PET imaging at baseline, 1 week and 6-8 weeks. CPAP begins after baseline PET scan.
Other Names:
  • PET
Other: Positron Emission Tomography
PET imaging at Baseline, 1 week and 6-8 weeks. CPAP begins after 6-8 week PET scan.
Other Names:
  • PET
Other: Positron Emission Tomography
PET scan at baseline and 6-8 weeks, no CPAP therapy
Other Names:
  • PET
Active Comparator: 2
Heart Failure-OSA Group, randomized to late CPAP
Other: Positron Emission Tomography
PET imaging at baseline, 1 week and 6-8 weeks. CPAP begins after baseline PET scan.
Other Names:
  • PET
Other: Positron Emission Tomography
PET imaging at Baseline, 1 week and 6-8 weeks. CPAP begins after 6-8 week PET scan.
Other Names:
  • PET
Other: Positron Emission Tomography
PET scan at baseline and 6-8 weeks, no CPAP therapy
Other Names:
  • PET
Other: 3
Heart Failure- no OSA, no CPAP therapy, observational group
Other: Positron Emission Tomography
PET imaging at baseline, 1 week and 6-8 weeks. CPAP begins after baseline PET scan.
Other Names:
  • PET
Other: Positron Emission Tomography
PET imaging at Baseline, 1 week and 6-8 weeks. CPAP begins after 6-8 week PET scan.
Other Names:
  • PET
Other: Positron Emission Tomography
PET scan at baseline and 6-8 weeks, no CPAP therapy
Other Names:
  • PET

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Measurements of oxidative metabolism (11C clearance rate constant 'k') and WMI
Time Frame: at 6-8 weeks
The differences in the measurements of oxidative metabolism (11C clearance rate constant 'k') and WMI will be analyzed using t-tests for the treatment groups
at 6-8 weeks
C-11 Hydroxyephedrine (HED) retention
Time Frame: 6-8 weeks
C-11 HED retention will be a measure myocardial SN pre-synaptic function in treatment groups
6-8 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
Changes in other parameters including New York Heart Association (NYHA) class, HR, BP, LV volumes, stroke work-index, and QoL scores will also be analyzed. The subgroups of ischemic and non-ischemic etiology will be analyzed
Time Frame: at 6-8 weeks
at 6-8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Ottawa Heart Institute Research Corporation

Collaborators

Heart and Stroke Foundation of Ontario

Investigators

  • Principal Investigator: Rob S Beanlands, MD, FRCP C, Ottawa Heart Institute Research Corporation

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

July 1, 2005

Primary Completion (Actual)

June 1, 2011

Study Completion (Actual)

December 1, 2011

Study Registration Dates

First Submitted

September 18, 2008

First Submitted That Met QC Criteria

September 19, 2008

First Posted (Estimate)

September 22, 2008

Study Record Updates

Last Update Posted (Actual)

May 30, 2018

Last Update Submitted That Met QC Criteria

May 28, 2018

Last Verified

May 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2005982-01H
  • HSFO #NA5665
  • HSFO #T6426

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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