Cardiovascular mortality in obstructive sleep apnoea treated with continuous positive airway pressure or oral appliance: An observational study

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background and objective</jats:title><jats:p>The objective of this study was to evaluate the long‐term cardiovascular mortality in patients with severe obstructive sleep apnoea (<jats:styled-content style="fixed-case">OSA</jats:styled-content>) treated with either continuous positive airway pressure (<jats:styled-content style="fixed-case">CPAP</jats:styled-content>) or mandibular advancing device (<jats:styled-content style="fixed-case">MAD</jats:styled-content>).</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>A non‐concurrent cohort study of 570 subjects with severe <jats:styled-content style="fixed-case">OSA</jats:styled-content> (apnoea/hypopnoea index (<jats:styled-content style="fixed-case">AHI</jats:styled-content>) ≥ 30/h) and a control group of 269 subjects (<jats:styled-content style="fixed-case">AHI</jats:styled-content> < 5/h) were followed up for a median of 79 months (interquartile range 76–88 months). All patients received <jats:styled-content style="fixed-case">CPAP</jats:styled-content> initially. <jats:styled-content style="fixed-case">MAD</jats:styled-content> was offered for those who were non‐adherent to <jats:styled-content style="fixed-case">CPAP</jats:styled-content>. The endpoint was cardiovascular death.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p> Two hundred and eight control subjects, 177 patients treated with <jats:styled-content style="fixed-case">CPAP</jats:styled-content>, 72 with <jats:styled-content style="fixed-case">MAD</jats:styled-content> and 212 who declined treatment were analysed. Forty‐two patients had a fatal cardiovascular event during the course of the study. The non‐apnoeic group had the lowest cardiovascular death rate (0.28 per 100 person‐years (95% confidence interval (<jats:styled-content style="fixed-case">CI</jats:styled-content>): 0.08–0.71)) followed by the <jats:styled-content style="fixed-case">CPAP</jats:styled-content>‐treated (0.56 per 100 person‐years (95% <jats:styled-content style="fixed-case">CI</jats:styled-content>: 0.20–1.23)) and the <jats:styled-content style="fixed-case">MAD</jats:styled-content>‐treated <jats:styled-content style="fixed-case">OSA</jats:styled-content> group (0.61 per 100 person‐years (95% <jats:styled-content style="fixed-case">CI</jats:styled-content>: 0.13–1.78)), with the highest cardiovascular mortality rate observed in the untreated <jats:styled-content style="fixed-case">OSA</jats:styled-content> group (2.1 per 100 person‐years (95% <jats:styled-content style="fixed-case">CI</jats:styled-content>: 1.37–2.92)). Although residual <jats:styled-content style="fixed-case">AHI</jats:styled-content> for <jats:styled-content style="fixed-case">MAD</jats:styled-content>‐treated patients was significantly higher than <jats:styled-content style="fixed-case">CPAP</jats:styled-content>‐treated patients (16.3 ± 5.1/h vs. 4.5 ± 2.3/h; <jats:italic><jats:styled-content style="fixed-case">P</jats:styled-content></jats:italic> < 0.001), there was no difference in cardiovascular death rate between the two groups (hazard ratio 1.08 (95% <jats:styled-content style="fixed-case">CI</jats:styled-content>: 0.55–1.74); <jats:italic><jats:styled-content style="fixed-case">P</jats:styled-content></jats:italic> = 0.71).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Both <jats:styled-content style="fixed-case">CPAP</jats:styled-content> and <jats:styled-content style="fixed-case">MAD</jats:styled-content> may be equally effective therapy in reducing the risk of fatal cardiovascular events in patients with severe <jats:styled-content style="fixed-case">OSA</jats:styled-content>.</jats:p></jats:sec>