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TerminatedNCT01217346Updated Aug 2, 2013

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

An observational study in Obstructive Sleep Apnea, Cardiac Syndrome X and Endothelial Dysfunction, sponsored by The University of Hong Kong. Terminated at 1 site in Hong Kong. Open to participants aged 18 Years to 70 Years. Per ClinicalTrials.gov, last updated 2013-08-02.

Sponsored by The University of Hong Kong · Observational

Study type
Observational
Model
Case-only
Time perspective
Cross-sectional
Enrollment
20
Ages
18 Years to 70 Years
Sex
All
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Study summary

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.

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Conditions studied

  • Obstructive Sleep Apnea
  • Cardiac Syndrome X
  • Endothelial Dysfunction
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In context

Sleep Apnea Syndromes

2,162 studies on the registry are indexed under Sleep Apnea Syndromes; 291 are open to participants now.

This study's enrollment of 20 is below the median of 109 across 654 observational studies indexed under Sleep Apnea Syndromes.

Browse Sleep Apnea Syndromes studies →

Lead sponsor

The University of Hong Kong is the lead sponsor of 1,262 studies on the registry; 340 are open to participants now.

Of its 8 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years to 70 Years
Sexes eligible
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

Exclusion Criteria:

  • Mentally incapacitated persons
  • Congestive heart failure
  • Other potential causes of orthopnea (severe chronic obstructive pulmonary disease, persistent asthma)
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Study design

Observational model
Case-only
Time perspective
Cross-sectional
Enrollment
20 participants (actual)

Groups and cohorts

  • cardiac syndrome X

    subjects fulfilling the clinical triad of cardiac syndrome X

    Other: no intervention is involved in this study

Interventions

  • Otherno intervention is involved in this study

    no intervention is involved in this study

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What researchers measure

Primary outcomes

  1. apnea hypopnea index

    assess apnea hypopnea index by overnight polysomnography, by a single admission to sleep laboratory

    Time frame: measure at a single time point when the subjects are admitted for overnight polysomnography

Secondary outcomes

  1. endothelial function

    assess endothelial function by EndoPAT 2000 (an non-invasive device) and peripheral blood endothelial progenitor cells

    Time frame: measured at a single time point when the subjects are admitted for overnight polysomnography

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Study locations

1 site
  • Queen Mary Hospital, The University of Hong Kong
    Hong Kong, 852, Hong Kong
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References and documents

Publications

  • Ip MS, Tse HF, Lam B, Tsang KW, Lam WK. Endothelial function in obstructive sleep apnea and response to treatment. Am J Respir Crit Care Med. 2004 Feb 1;169(3):348-53. doi: 10.1164/rccm.200306-767OC. Epub 2003 Oct 9. PubMed 14551167 ↗
  • Loui WS, Blackshear JL, Fredrickson PA, Kaplan J. Obstructive sleep apnea manifesting as suspected angina: report of three cases. Mayo Clin Proc. 1994 Mar;69(3):244-8. doi: 10.1016/s0025-6196(12)61063-5. PubMed 8133662 ↗
  • Philip P, Guilleminault C. ST segment abnormality, angina during sleep and obstructive sleep apnea. Sleep. 1993 Sep;16(6):558-9. doi: 10.1093/sleep/16.6.558. No abstract available. PubMed 8235241 ↗
  • Chan HS, Chiu HF, Tse LK, Woo KS. Obstructive sleep apnea presenting with nocturnal angina, heart failure, and near-miss sudden death. Chest. 1991 Apr;99(4):1023-5. doi: 10.1378/chest.99.4.1023. PubMed 2009755 ↗
  • Melikian N, De Bruyne B, Fearon WF, MacCarthy PA. The pathophysiology and clinical course of the normal coronary angina syndrome (cardiac syndrome X). Prog Cardiovasc Dis. 2008 Jan-Feb;50(4):294-310. doi: 10.1016/j.pcad.2007.01.003. No abstract available. PubMed 18156008 ↗
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 2, 2013, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT01217346
Lead sponsor
The University of Hong Kong
First posted
Oct 8, 2010
Start date
Feb 2009
Primary completion
Dec 2012
Completion
Dec 2012
Last update
Aug 2, 2013

Study contacts

Macy MS Lui
principal investigator · Queen Mary Hospital, The University of Hong Kong

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is terminated, as verified in Aug 2013. You cannot join it, but the record below documents what was studied.

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