Respiratory polygraphy patterns and risk of cardiovascular events in patients with acute coronary syndrome

Abstract

<b>Background:</b> Recent studies have suggested that the population with a first event of acute coronary syndrome (ACS) is susceptible to the deleterious effects of obstructive sleep apnea (OSA)(Zapater, A. et al. <i>Am J Respir Crit Care Med</i> 2020; 202:1698-1706). <b>Aim and objectives:</b> We explore respiratory polygraphy parameters that are associated with an increased risk of recurrence cardiovascular events in this subgroup of patients with ACS. <b>Methods:</b> Post-hoc analysis of the ISAACC study, including 723 patients admitted for a first ACS (NCT01335087). A principal component analysis (PCA) was performed using six respiratory polygraphy parameters: apnea-hypopnea index (AHI), oxygen desaturation index, mean and minimum oxygen saturation (SaO₂), average duration of events and percentage of time with SaO₂&lt;90%. <b>Results:</b> PCA showed that two respiratory polygraphy patterns accounted for 70% of variance. A first pattern was mainly characterized by low mean SaO₂ and events with severe desaturation (<i>High Time with SaO₂&lt;90%</i>) and a second pattern is characterized by high mean SaO₂ and longer duration events with severe desaturation (<i>Low Time with SaO₂&lt;90%</i>). The <i>Low Time with SaO2&lt;90%</i> pattern was associated with an increased risk of recurrent cardiovascular events with an adjusted HR (95% CI) of 2.44 (1.07 to 5.56; p-value=0.03). For the <i>High Time with SaO₂&lt;90%</i> pattern, no significant association was found for the risk of recurrent cardiovascular events. <b>Conclusions:</b> A sleep apnea pattern, mainly characterized by high mean SaO₂ and longer duration events with severe desaturation, is associated with a high risk of recurrent cardiovascular events in patients who have suffered a first ACS.