Prevalence of obstructive sleep apnoea in acute coronary syndrome: Routine screening in intensive coronary care units

Abstract

Introduction: Increased evidence has shown that, despite the maximum care afforded to patients admitted with acute coronary syndromes (ACS), a residual risk of mortality remains, in which obstructive sleep apnoea (OSA) appears to be a largely undiagnosed factor, particularly in the intensive cardiac care unit (ICCU). The purpose of this study is to determine whether the systematic screening for sleep-disordered breathing (SDB) is feasible and may be recommended. The aims of our study are to determine: (1) The estimated prevalence of OSA in patients admitted to the ICCU for ACS determined by a validated, user-friendly portable screening device; (2) The feasibility of the screening in this context; (3) To assess any negative impact of OSA on the severity of ACS.

Patients and methods: This is an observational study of 101 patients admitted to the ICCU for ACS showing no clinical evidence of heart failure (HF). In the 24-72hours following admission, they underwent an overnight sleep study using a 3-channel portable screening device with automatic analysis.

Results: Sixty-two out of the 101 patients proved positive to the screening test, and its feasibility was acceptable. OSA patients tended to have greater peak levels of hs-cTnT (3685±3576ng/L versus 2830±3333ng/L, P=0.08) than the non-OSA group. Compared with the non-OSA group, OSA patients presented more severe ACS, with a greater average GRACE score at admission of 112.2±26.3 (versus 98.4±19.2, P<0.001). In the OSA group, we found a statistically significant inverse correlation between the apnoea-hypopnea index (AHI) and the left ventricular ejection fraction (LVEF) in the linear regression analysis (r=-0.26; P=0.037).

Conclusions: A systematic screening of patients in the ICCU is acceptable. OSA is frequently found in the acute phase of ischaemic heart disease and its presence is associated with more severe ACS and a poorer left ventricle systolic function.

Keywords: Acute myocardial infarction; Appareil de dépistage portable; Heart failure; Infarctus du myocarde; Insuffisance cardiaque; Portable monitoring screening device; Sleep-disordered breathing; Trouble respiratoire du sommeil.