Association Between Nocturnal Hypoxemia Parameters and Coronary Microvascular Dysfunction: A Cross-Sectional Study

Lanxin Feng,1 Xin Zhao,1 Jianqiao Song,2 Shuwen Yang,1 Jianping Xiang,3 Min Zhang,1 Chenchen Tu,1 Xiantao Song1 1Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, People’s Republic of China; 2Sun Yat Sen University, Zhongshan School of Medicine, Guangzhou, People’s Republic of China; 3ArteryFlow Technology Co., Ltd., Hangzhou, People’s Republic of ChinaCorrespondence: Chenchen Tu, Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, People’s Republic of China, Email [email protected]: There is a connection between obstructive sleep apnea (OSA) and coronary microvascular dysfunction (CMD), but the underlying mechanisms remain unclear. This study aims to evaluate the correlation between OSA-related nocturnal hypoxemia parameters and CMD.Methods: This is an observational, single-center study that included patients who underwent polysomnography and coronary angiography during hospitalization. The presence of CMD was determined by angio-based index of microcirculatory resistance (AccuIMR). Categorical variables were compared using chi-square test or Fisher exact test. The t-test and Mann–Whitney U-test were used to compare normally and non-normally distributed continuous variables, respectively. Univariate and multivariable logistic regression analyses were performed to evaluate the relationship between nocturnal hypoxemia parameters and CMD.Results: A total of 133 patients were included in this study, of whom 72 (54.14%) had evidence of CMD. Patients with CMD exhibited a higher prevalence of OSA and experienced more severe nocturnal hypoxia. After adjusting for potential confounding factors, minimum oxygen saturation (minSpO2) ≤ 90% (OR 5.89; 95% CI 1.73– 19.99; P=0.004) and the percentage of time spent with oxygen saturation below 90% (T90) ≥ 5% (OR 3.13; 95% CI 1.05– 9.38; P=0.041) were independently associated with CMD. However, no significant association was observed between apnea-hypopnea index (AHI) and CMD.Conclusion: Parameters of nocturnal hypoxemia are associated with CMD. Hypoxemia parameters may more sensitively reflect the correlation between OSA and CMD than AHI.Keywords: obstructive sleep apnea, coronary microvascular dysfunction, nocturnal hypoxemia, cardiology, dentistry