Association of obstructive sleep apnoea with long-term cardiovascular events in patients with acute coronary syndrome with or without hypertension: insight from the OSA-ACS project

BACKGROUND: A close relationship exists between obstructive sleep apnoea (OSA) and hypertension. However, the impact of hypertension on the prognostic significance of OSA in patients with acute coronary syndrome (ACS) remains unclear. METHODS: This is a post hoc analysis of the OSA-ACS project, which consecutively included patients with ACS and receiving overnight sleep study from June 2015 to January 2020. OSA was defined as AHI ≥15 events/hour. The primary outcome was major adverse cardiovascular and cerebrovascular events (MACCE), including a composite of cardiovascular death, myocardial infarction, stroke, ischemia-driven revascularisation or hospitalisation for unstable angina or heart failure. RESULTS: A total of 1927 patients with ACS were finally enrolled in this study. The mean patient age was 56.4±10.5 years. Among them, 1247 (64.7%) patients had hypertension, and 1014 (52.6%) patients had OSA. During 2.9 (1.5, 3.6) years of follow-up, OSA was associated with an increased risk of MACCE among patients with hypertension (HR=1.35, 95% CI 1.04 to 1.75, p=0.02), but not in patients without hypertension (HR=1.15, 95% CI 0.79 to 1.68, p=0.47). The interaction between OSA and hypertension for MACCE was not statistically significant (interaction p=0.29). For patients with pre-existing hypertension, OSA was associated with an increased risk of MACCE only among those with grade 3 hypertension (HR 1.54, 95% CI 1.12 to 2.13, p=0.008), but not those with grade 1 or 2 hypertension. CONCLUSIONS: OSA was associated with an increased risk of MACCE following ACS in patients with hypertension, especially in patients with pre-existing severe hypertension. These findings highlight the importance of identifying OSA in ACS patients with hypertension. TRIAL REGISTRATION NUMBER: NCT03362385.