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Predicting Successful Sleep Apnea Treatment With Acetazolamide in Heart Failure Patients (HF-ACZ)

This study has been completed.
American Heart Association
National Institutes of Health (NIH)
Information provided by (Responsible Party):
David Andrew Wellman, Brigham and Women's Hospital Identifier:
First received: June 20, 2011
Last updated: January 4, 2017
Last verified: January 2017

The ultimate goal is to improve our understanding of the pathophysiology and resistance to effective treatment of sleep disordered breathing in patients with heart failure, with a focus on selecting patients that will benefit specifically from acetazolamide treatment.

The study addresses three primary hypotheses: 1) Acetazolamide treatment will reduce the apnea-hypopnea index and improve markers of heart-failure severity in heart-failure patients with sleep apnea. 2) Acetazolamide will provide the greatest improvement in patients with the most severe ventilatory control instability (strongest chemoreflex response to carbon dioxide; highest loop gain). 3) Acetazolamide will act primarily via stabilizing ventilatory control (reducing loop gain), rather than via improvement to upper airway anatomy, pulmonary congestion, and cardiac function.

Condition Intervention
Heart Failures
Controls Without Heart Failure
Drug: Acetazolamide
Drug: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Participant, Investigator)
Primary Purpose: Basic Science
Official Title: Physiological Study to Predict Successful Sleep Apnea Treatment With Acetazolamide in Heart Failure Patients

Resource links provided by NLM:

Further study details as provided by Brigham and Women's Hospital:

Primary Outcome Measures:
  • The severity of sleep disordered breathing (apnea-hypopnea index, AHI) [ Time Frame: 1 week ]
    Nocturnal arterial oxygenation and percent of stable breathing time will also be assessed.

Secondary Outcome Measures:
  • Ventilatory stability, i.e. loop gain, ventilatory sensitivity to carbon dioxide [ Time Frame: 1 week ]
    The severity of ventilatory instability is expected to predict treatment failure, and the magnitude of its improvement is expected to be associated with a positive primary outcome.

  • Sympathetic activity (urinary norepinephrine) [ Time Frame: 1 week ]
    Plasma norepinephrine and epinephrine will be measured to confirm results.

  • Cardiac function, assessed by echocardiography [ Time Frame: 1 week ]
    Volumes and hemodynamics will be assessed.

  • Closing volume [ Time Frame: 1 week ]
    Higher pulmonary closing volume can indicate subclinical pulmonary edema, which is expected to improve if there is any considerable diuretic effect of acetazolamide or reduction in left ventricular filling pressure. Respiratory system conductance will also be assessed.

  • Brain natriuretic peptide (NT-proBNP) [ Time Frame: 1 week ]
    Other known biomarkers will also be assessed in parallel to confirm any observed benefit

  • Subjective sleep quality, breathlessness, fatigue (Quality of life) [ Time Frame: 1 week ]
    pittsburgh sleep quality index; kansas city cardiomyopathy questionnaire

  • Troponin I [ Time Frame: 1 week ]
    Other known biomarkers will also be assessed in parallel to confirm any observed benefit

Enrollment: 29
Study Start Date: August 2011
Study Completion Date: December 2016
Primary Completion Date: December 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Acetazolamide Drug: Acetazolamide
4 mg/kg, once daily before bed, for 7 days
Other Name: Diamox
Placebo Comparator: Sugar pill Drug: Placebo
4 mg/kg, once daily before bed, for 7 days


Ages Eligible for Study:   18 Years to 89 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria (Heart failure patients)

  • Left ventricular ejection fraction (EF) <50%, or heart failure with preserved EF
  • Age 18-89

Inclusion Criteria (Controls)

  • No history or evidence of heart failure
  • Age 18-89

Exclusion Criteria:

  • severe obstructive respiratory disease
  • unstable heart failure status
  • recent use of positive airway pressure therapy
  • current use of opioids, benzodiazepines
  • severe kidney disease
  • severe anemia
  Contacts and Locations
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Please refer to this study by its identifier: NCT01377987

United States, Massachusetts
Brigham and Women's Hospital
Boston, Massachusetts, United States, 02115
Sponsors and Collaborators
David Andrew Wellman
American Heart Association
National Institutes of Health (NIH)
Principal Investigator: Andrew Wellman, MD, PhD Brigham and Women's Hospital
Principal Investigator: Atul Malhotra, MD Brigham and Women's Hospital
  More Information

Responsible Party: David Andrew Wellman, Associate Professor of Medicine, Brigham and Women's Hospital Identifier: NCT01377987     History of Changes
Other Study ID Numbers: 2011-P-000049/1
Study First Received: June 20, 2011
Last Updated: January 4, 2017

Additional relevant MeSH terms:
Heart Failure
Heart Diseases
Cardiovascular Diseases
Carbonic Anhydrase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Natriuretic Agents
Physiological Effects of Drugs processed this record on May 23, 2017