Clinical trial NCT01217346: A Prevalence Study of Obstructive Sleep Apnea in Subjects With Chest Pain, Positive Exercise Treadmill Test and Normal Coronary Angiogram
Study type: OBSERVATIONAL
Overall status: TERMINATED
Conditions: Obstructive Sleep Apnea
Cardiac Syndrome X
Endothelial Dysfunction
Lead sponsor: The University of Hong Kong
Sponsor class: OTHER
First posted: 2010-10-08
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Subjects with chest pain, positive exercise treadmill test and normal coronary angiogram

Brief 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.


Eligibility criteria: 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)

Primary outcomes:
measure: apnea hypopnea index
timeFrame: measure at a single time point when the subjects are admitted for overnight polysomnography
Secondary outcomes:
measure: endothelial function
timeFrame: measured at a single time point when the subjects are admitted for overnight polysomnography
Other outcomes:
Locations:
city: Hong Kong
country: Hong Kong
facility: Queen Mary Hospital, The University of Hong Kong
Study officials:
affiliation: Queen Mary Hospital, The University of Hong Kong
name: Macy MS Lui
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: 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.
citation: 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.
citation: 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.
citation: 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.