{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,24]],"date-time":"2026-02-24T06:04:21Z","timestamp":1771913061370,"version":"3.50.1"},"reference-count":30,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2025,8,21]],"date-time":"2025-08-21T00:00:00Z","timestamp":1755734400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Scientific Research Projects Coordination Unit of Marmara University","award":["10507"],"award-info":[{"award-number":["10507"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background\/Objectives: Cardiac Syndrome X (CSX) is associated with significant physical and psychiatric morbidity despite no obvious effect on long-term mortality. Obstructive sleep apnea (OSA) is a prevalent condition in close association with numerous cardiovascular diseases. The precise relation between CSX and OSA remains unclear. The aim of this study is to explore the relation between OSA and CSX, as well as the impact of continuous positive airway pressure (CPAP) therapy on myocardial ischemia. Methods: This single-center prospective cohort study examined patients who were selected consecutively from the Cardiology Outpatient Clinic with angina or angina-equivalent complaints and with ischemia on myocardial perfusion scintigraphy (MPS), and who were subsequently diagnosed with CSX via coronary angiography. Patients with previous myocardial infarction and previous percutaneous coronary intervention or coronary artery by-pass grafting surgery were excluded, since these conditions could not be regarded as CSX. The presence of OSA was explored by polysomnography (PSG). CPAP therapy was applied for three months to those diagnosed with OSA. Following a three-month course of treatment, a myocardial perfusion scintigraphy (MPS) was conducted, to assess myocardial ischemia. The IBM\u00ae SPSS Statistics Version 26 software was employed for the purpose of statistical analysis. Results: Among the 27 consecutive patients (mean age 58.1 \u00b1 9.6 years and 22 female) with CSX 24 patients were found to have OSA according to PSG examination. CPAP therapy was applied to 17 patients (mean age 56.4 \u00b1 8.6 years, 14 female) who accepted to participate in the treatment phase of the study. Following a three-month course of treatment, myocardial ischemia was reduced in 13 of the 17 patients. There were statistically significant correlations between the reduction in myocardial ischemia and patient\u2019s diagnosis of hypertension (p = 0.006), higher serum HDL cholesterol levels (p = 0.009), and adherence to CPAP therapy (p = 0.047). Conclusions: The prevalence of OSA is significantly higher among the patients with CSX compared to the general adult population. In patients with CSX and OSA, improvement in myocardial ischemia was observed in MPS following CPAP therapy.<\/jats:p>","DOI":"10.3390\/jcm14165897","type":"journal-article","created":{"date-parts":[[2025,8,21]],"date-time":"2025-08-21T15:19:02Z","timestamp":1755789542000},"page":"5897","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The Relationship Between Cardiac Syndrome X and Obstructive Sleep Apnea and the Effects of Sleep Apnea Treatment on Myocardial Ischemia"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7028-6310","authenticated-orcid":false,"given":"Umit","family":"Ozturk","sequence":"first","affiliation":[{"name":"Department of Cardiology, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Beste","family":"Ozben","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mustafa Kursat","family":"Tigen","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Baran","family":"Balcan","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Department of Pulmonology, Ko\u00e7 University, 34450 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tunc","family":"Ones","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5871-7301","authenticated-orcid":false,"given":"Gulin","family":"Sunter","sequence":"additional","affiliation":[{"name":"Department of Neurology, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nuh","family":"Filizoglu","sequence":"additional","affiliation":[{"name":"Department of Nuclear Medicine, Istanbul L\u00fctfi K\u0131rdar Training and Research Hospital, 34760 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Murat","family":"Sunbul","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0901-9958","authenticated-orcid":false,"given":"Emre","family":"Gurel","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Altug","family":"Cincin","sequence":"additional","affiliation":[{"name":"Department of Cardiology, Marmara University, 34899 Istanbul, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,21]]},"reference":[{"key":"ref_1","first-page":"463","article-title":"Cardiac Syndrome X: Update 2014","volume":"32","author":"Agrawal","year":"2014","journal-title":"Cardiol. 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