Severity of obstructive sleep apnoea predicts coronary artery plaque burden: a coronary computed tomographic angiography study

Obstructive sleep apnoea (OSA) is associated with significantly increased risk of cardiovascular disease. Carotid ultrasonography and retrospective, uncontrolled, coronary imaging studies have suggested an association of OSA with subclinical atherosclerosis, but there is a lack of prospective, controlled studies directly evaluating the relationship of OSA with occult coronary artery disease. We performed coronary computed tomographic angiography and inpatient-attended sleep studies on a cohort of otherwise healthy males attending our sleep laboratory, and compared coronary artery plaque volume between subjects with low and high apnoea/hypopnoea index (AHI) scores. 29 subjects participated. The median AHI was 15.5 events · h(-1), with subjects who scored above this classified as high AHI. No significant differences were observed in demographic, anthropometric and clinical variables between the high- and low-AHI groups. Coronary plaque volume was significantly greater in the high-AHI group (mean plaque volume 2.6 ± 0.7 mm(2) versus 0.8 ± 0.2 mm(2); p=0.017) and, furthermore, correlated significantly with AHI (Spearman's r=0.433; p=0.019). Following adjustment for dyslipidaemia and fasting plasma glucose levels, AHI remained a significant predictor of plaque volume (standardised β=0.424; p=0.027). In this prospective case-control study, we found that severity of OSA may predict occult coronary atherosclerosis in otherwise healthy overweight or obese male subjects.