Epidemiology
Obstructive sleep apnea raises cardiovascular risk only in ACS patients with above-median Lp(a), OSA-ACS cohort of 1137 (Sleep 2026)
Original title: Obstructive sleep apnea, lipoprotein(a) and long-term cardiovascular outcomes in acute coronary syndrome
Sub-analysis of the prospective OSA-ACS cohort (NCT03362385) of 1137 patients with acute coronary syndrome, 608 (53.5%) diagnosed with obstructive sleep apnea (OSA, apnoea-hypopnoea index 15 or more events/hour), followed a median 3.6 years for major adverse cardiovascular and cerebrovascular events (MACCE). OSA was associated with higher MACCE risk in patients with Lp(a) above the cohort median (hazard ratio 1.59, 95% CI 1.12-2.26) but not in those at or below median Lp(a) (hazard ratio 1.09, 95% CI 0.80-1.49), with a consistent dose-response across Lp(a) tertiles and quartiles. Among patients with high Lp(a), OSA was linked to a higher prevalence of high-risk plaque features (51.4% vs 33.3%) and low-attenuation plaque (50.0% vs 32.8%) on coronary CT. The authors suggest Lp(a) may help identify ACS patients whose cardiovascular risk from OSA is high enough to prioritise for OSA treatment trials.
Original abstract
Study Objectives: The impact of obstructive sleep apnea (OSA) on subsequent cardiovascular events in patients with acute coronary syndrome (ACS) remains debated. This study aims to investigate whether the association of OSA with cardiovascular events is affected by lipoprotein (a) [Lp(a)] levels.
Methods: This is a sub-analysis of prospective cohort study (OSA-ACS, NCT03362385) enrolled ACS patients. OSA defined as an apnea-hypopnea index ≥15 events/h. The effects of OSA on subsequent cardiovascular outcomes were evaluated across varying Lp(a) thresholds. Coronary plaque features by coronary computed tomography angiography were also analyzed.
Results: A total of 1137 patients were enrolled, 608 patients (53.5%) were diagnosed with OSA. At a median follow-up of 3.6 years, OSA was associated with a higher risk of major adverse cardiovascular and cerebrovascular events (MACCE) in patients with Lp(a) level >median (HR 1.59, 95% CI 1.12-2.26, P=0.009), but not in patients with Lp(a) level ≤median (HR 1.09, 95% CI 0.80-1.49, P=0.60). There were consistent increases in HRs for MACCE in the OSA group with Lp(a) levels rising, as stratified by tertiles or quartiles of Lp(a). In patients with Lp(a) level >median, OSA demonstrated a higher prevalence of ≥1 high-risk plaque (HRP) feature (51.4% vs. 33.3%, P=0.03) and low-attenuation plaque (50.0% vs. 32.8, P=0.04) per vessel than non-OSA.
Conclusion: OSA was associated with a continuously increased cardiovascular risk and a higher prevalence of HRP features as Lp(a) levels rose. Lp(a) may help identify ACS patients at higher cardiovascular risk, in whom the efficacy of OSA treatment should be further investigated.
epidemiologyplaque imagingrisk
Summary written by lp-a.org from the published abstract; figures as published. Page updated 17 August 2026. Methods.