Does CPAP improve endothelial and lung epithelial biomarkers in patients with OSA following coronary revascularization?
CPAP therapy in OSA patients post-revascularization promotes a proinflammatory endothelial profile, which may explain its failure to reduce cardiovascular risk in this population.
BACKGROUND: Continuous positive airway pressure (CPAP) has failed to reduce cardiovascular risk in obstructive sleep apnoea (OSA) in randomized trials. CPAP increases angiopoietin-2, a lung distension-responsive endothelial proinflammatory marker associated with increased cardiovascular risk. We investigated whether CPAP has unanticipated proinflammatory effects in patients with OSA and cardiovascular disease. METHODS: Patients with OSA (apnoea-hypopnea index AHI ≥15 events/h without excessive sleepiness) in the Randomized Intervention with CPAP in Coronary Artery Disease and OSA study were randomized to CPAP or usual care following coronary revascularization. Changes in plasma levels of biomarkers of endothelial (angiopoietin-2, Tie-2, E-selectin, vascular endothelial growth factor VEGF-A) and lung epithelial (soluble receptor of advanced glycation end-products sRAGE) function from baseline to 12-month follow-up were compared across groups and associations with cardiovascular morbidity and mortality assessed. FINDINGS: , AHI 41 ± 23 events/h) and 91 patients without OSA participated. Angiopoietin-2 remained elevated whereas VEGF-A declined significantly over 12 months in the CPAP group (n = 91). In contrast, angiopoietin-2 significantly declined whereas VEGF-A remained elevated in the usual care (n = 98) and OSA-free groups. The changes in angiopoietin-2 and VEGF-A were significantly different between CPAP and usual care, whereas Tie-2, sRAGE and E-selectin were similar. Greater 12-month levels of angiopoietin-2 were associated with greater mortality. Greater CPAP levels were associated with worse cardiovascular outcomes. INTERPRETATION: Greater CPAP levels increase proinflammatory, lung distension-responsive angiopoietin-2 and reduce cardioprotective angiogenic factor VEGF-A compared to usual care, which may counteract the expected cardiovascular benefits of treating OSA. FUNDING: National Institutes of Health/National Heart, Lung, and Blood Institute; Swedish Research Council; Swedish Heart-Lung Foundation; ResMed Foundation.
Peker et al. (Sat,) studied this question.