{"title":"Nocturnal hypoxemic burden in patients with heart failure: Emerging prognostic role of its nonspecific component","authors":"","doi":"10.1016/j.ahj.2024.06.011","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><p>Nocturnal hypoxemic burden has been shown to be a robust, independent predictor of all-cause mortality in patients with heart failure and reduced ejection fraction (HFrEF) and to occur in a severe form even in patients with low or negligible frequency of respiratory events (apneas/hypopneas). This suggests the existence of two components of hypoxemic burden: one unrelated to respiratory events and the other related. The aim of this study was to characterize these two components and to evaluate their prognostic value.</p></div><div><h3>Methods</h3><p>Nocturnal hypoxemic burden was assessed in a cohort of 280 patients with HFrEF by measuring the percentage of sleep with an oxygen saturation (SpO<sub>2</sub>) <90% (T90), and the area of the SpO<sub>2</sub> curve below 90% (Area90). Both indices were also recalculated within the sleep segments associated with respiratory events (event-related component: T90<sub>Eve</sub>, Area90<sub>Eve</sub>) and outside these segments (nonspecific component: T90<sub>Nspec</sub>, Area90<sub>Nspec</sub>). The outcome of the survival analysis (Cox regression) was all-cause mortality.</p></div><div><h3>Results</h3><p>During a median follow-up of 60 months, 87 patients died. T90, Area90, and their components were significant in univariate analysis (<em>P</em> < .05 all). However, when these indices were adjusted for known risk factors, T90, T90<sub>Nspec</sub>, Area90, and Area90<sub>Nspec</sub> remained statistically significant (<em>P = .</em>018, hazard ratio (HR)=1.12, 95%CI=(1.02, 1.23); <em>P = .</em>007, HR=1.20, 95% CI = [1.05, 1.37]; <em>P</em> = .020, HR = 1.05, 95% CI = [1.01, 1.10]; <em>P</em> = .0006, HR = 1.15, 95% CI = [1.06, 1.25]), whereas T90<sub>Eve</sub> and Area90<sub>Eve</sub> did not (<em>P</em> = .27, <em>P</em> = .28). These results were internally validated using bootstrap resampling.</p></div><div><h3>Conclusions</h3><p>By demonstrating a significant independent association of nonspecific hypoxemic burden with all-cause mortality, this study suggests that this component of total nocturnal hypoxemic burden may play an important prognostic role in patients with HFrEF.</p></div>","PeriodicalId":7868,"journal":{"name":"American heart journal","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"American heart journal","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0002870324001662","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CARDIAC & CARDIOVASCULAR SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
Background
Nocturnal hypoxemic burden has been shown to be a robust, independent predictor of all-cause mortality in patients with heart failure and reduced ejection fraction (HFrEF) and to occur in a severe form even in patients with low or negligible frequency of respiratory events (apneas/hypopneas). This suggests the existence of two components of hypoxemic burden: one unrelated to respiratory events and the other related. The aim of this study was to characterize these two components and to evaluate their prognostic value.
Methods
Nocturnal hypoxemic burden was assessed in a cohort of 280 patients with HFrEF by measuring the percentage of sleep with an oxygen saturation (SpO2) <90% (T90), and the area of the SpO2 curve below 90% (Area90). Both indices were also recalculated within the sleep segments associated with respiratory events (event-related component: T90Eve, Area90Eve) and outside these segments (nonspecific component: T90Nspec, Area90Nspec). The outcome of the survival analysis (Cox regression) was all-cause mortality.
Results
During a median follow-up of 60 months, 87 patients died. T90, Area90, and their components were significant in univariate analysis (P < .05 all). However, when these indices were adjusted for known risk factors, T90, T90Nspec, Area90, and Area90Nspec remained statistically significant (P = .018, hazard ratio (HR)=1.12, 95%CI=(1.02, 1.23); P = .007, HR=1.20, 95% CI = [1.05, 1.37]; P = .020, HR = 1.05, 95% CI = [1.01, 1.10]; P = .0006, HR = 1.15, 95% CI = [1.06, 1.25]), whereas T90Eve and Area90Eve did not (P = .27, P = .28). These results were internally validated using bootstrap resampling.
Conclusions
By demonstrating a significant independent association of nonspecific hypoxemic burden with all-cause mortality, this study suggests that this component of total nocturnal hypoxemic burden may play an important prognostic role in patients with HFrEF.
期刊介绍:
The American Heart Journal will consider for publication suitable articles on topics pertaining to the broad discipline of cardiovascular disease. Our goal is to provide the reader primary investigation, scholarly review, and opinion concerning the practice of cardiovascular medicine. We especially encourage submission of 3 types of reports that are not frequently seen in cardiovascular journals: negative clinical studies, reports on study designs, and studies involving the organization of medical care. The Journal does not accept individual case reports or original articles involving bench laboratory or animal research.