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A Prevalence Study of Obstructive Sleep Apnea in Subjects With Chest Pain, Positive Exercise Treadmill Test and Normal Coronary Angiogram

This study has been terminated.
Information provided by:
The University of Hong Kong Identifier:
First received: October 4, 2010
Last updated: August 1, 2013
Last verified: August 2013
Cardiac syndrome X consists of a triad of chest pain, abnormal exercise stress testing and normal coronary angiogram, and is hypothesized to be related to endothelial dysfunction. Endothelial dysfunction is also reported to be linked to obstructive sleep apnea. While chest pain can be one of potential presenting symptoms of obstructive sleep apnea, the investigators hypothesize that obstructive sleep apnea is common in subjects with cardiac syndrome X.

Condition Intervention
Obstructive Sleep Apnea
Cardiac Syndrome X
Endothelial Dysfunction
Other: no intervention is involved in this study

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Cross-Sectional

Resource links provided by NLM:

Further study details as provided by The University of Hong Kong:

Primary Outcome Measures:
  • apnea hypopnea index [ Time Frame: measure at a single time point when the subjects are admitted for overnight polysomnography ]
    assess apnea hypopnea index by overnight polysomnography, by a single admission to sleep laboratory

Secondary Outcome Measures:
  • endothelial function [ Time Frame: measured at a single time point when the subjects are admitted for overnight polysomnography ]
    assess endothelial function by EndoPAT 2000 (an non-invasive device) and peripheral blood endothelial progenitor cells

Enrollment: 20
Study Start Date: February 2009
Study Completion Date: December 2012
Primary Completion Date: December 2012 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
cardiac syndrome X
subjects fulfilling the clinical triad of cardiac syndrome X
Other: no intervention is involved in this study
no intervention is involved in this study


Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Subjects with chest pain, positive exercise treadmill test and normal coronary angiogram

Inclusion Criteria:

  • Age ≧18 years, < 70 years
  • Symptom of chest pain occurring at least once in the preceding year
  • Positive exercise treadmill test
  • Negative coronary angiogram
  • Mentally fit to give informed consent

Exclusion Criteria:

  • Mentally incapacitated persons
  • Congestive heart failure
  • Other potential causes of orthopnea (severe chronic obstructive pulmonary disease, persistent asthma)
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Please refer to this study by its identifier: NCT01217346

Hong Kong
Queen Mary Hospital, The University of Hong Kong
Hong Kong, Hong Kong, 852
Sponsors and Collaborators
The University of Hong Kong
Principal Investigator: Macy MS Lui Queen Mary Hospital, The University of Hong Kong
  More Information

Responsible Party: Lui Mei Sze Macy, Queen Mary Hospital, The University of Hong Kong Identifier: NCT01217346     History of Changes
Other Study ID Numbers: UW 09-127
Study First Received: October 4, 2010
Last Updated: August 1, 2013

Additional relevant MeSH terms:
Sleep Apnea Syndromes
Sleep Apnea, Obstructive
Microvascular Angina
Respiration Disorders
Respiratory Tract Diseases
Sleep Disorders, Intrinsic
Sleep Wake Disorders
Nervous System Diseases
Angina Pectoris
Myocardial Ischemia
Heart Diseases
Cardiovascular Diseases
Vascular Diseases processed this record on May 25, 2017