Phenotyping of Sleep-Disordered Breathing in Patients With Chronic Heart Failure With Reduced Ejection Fraction-the SchlaHF Registry

Abstract

Background: Different sleep-disordered breathing (SDB) phenotypes, including coexisting obstructive and central sleep apnea (OSA-CSA), have not yet been characterized in a large sample of patients with heart failure and reduced ejection fraction (HFrEF) receiving guideline-based therapies. Therefore, the aim of the present study was to determine the proportion of OSA, CSA, and OSA-CSA, as well as periodic breathing, in HFrEF patients with SDB.

Methods and results: The German SchlaHF registry enrolled patients with HFrEF receiving guideline-based therapies, who underwent portable SDB monitoring. Polysomnography (n=2365) was performed in patients with suspected SDB. Type of SDB (OSA, CSA, or OSA-CSA), the occurrence of periodic breathing (proportion of Cheyne-Stokes respiration ≥20%), and blood gases were determined in 1557 HFrEF patients with confirmed SDB. OSA, OSA-CSA, and CSA were found in 29%, 40%, and 31% of patients, respectively; 41% showed periodic breathing. Characteristics differed significantly among SDB groups and in those with versus without periodic breathing. There was a relationship between greater proportions of CSA and the presence of periodic breathing. Risk factors for having CSA rather than OSA were male sex, older age, presence of atrial fibrillation, lower ejection fraction, and lower awake carbon dioxide pressure (pco₂). Periodic breathing was more likely in men, patients with atrial fibrillation, older patients, and as left ventricular ejection fraction and awake pco₂ decreased, and less likely as body mass index increased and minimum oxygen saturation decreased.

Conclusions: SchlaHF data show that there is wide interindividual variability in the SDB phenotype of HFrEF patients, suggesting that individualized management is appropriate.

Clinical trial registration: URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01500759.

Keywords: heart failure; phenotypes; sleep apnea; sleep disorders.

Figure 1

Patient populations and flow in the SchlaHF registry. AHI indicates apnea‐hypopnea index; CSR, Cheyne‐Stokes respiration; HFrEF, heart failure with reduced ejection fraction; NYHA, New York Heart Association; PSG, polysomnography; SDB, sleep‐disordered breathing. ^† SDB or typical clinical symptoms indicative of SDB. *Incomplete data included patients with no data on SDB screening (n=390), age (n=1), body mass index (BMI; n=1), left ventricular ejection fraction (LVEF; n=1946), NYHA class (n=1957), atrial fibrillation (n=1977), and etiology of HFrEF (patients could have more than 1 piece of data missing). The high number of missing values for BMI, LVEF, and NYHA was due to recording of these variables being introduced to the registry after a protocol change.

Figure 2

Prevalence of obstructive and central sleep apnea by sex. CSA indicates central sleep apnea (defined as cAHI/AHI ≥80%); OSA, obstructive sleep apnea (defined as cAHI/AHI 0% to 19.9%); OSA+CSA, obstructive sleep apnea+central sleep apnea (defined as cAHI/AHI 20% to 79.9%). AHI indicates apnea‐hypopnea index; cAHI, central AHI.

Figure 3

Prevalence of periodic breathing (defined as Cheyne‐Stokes respiration [CSR] ≥20%) according to sleep apnea type. CSA indicates central sleep apnea (defined as cAHI/AHI ≥80.0%); OSA, obstructive sleep apnea (defined as cAHI/AHI 0% to 19.9%); OSA+CSA, obstructive sleep apnea+central sleep apnea (defined as cAHI/AHI 20% to 79.9%). AHI indicates apnea‐hypopnea index; cAHI, central AHI.

Figure 4

Forest plot of risk factors for central sleep apnea (higher cAHI/AHI percentage) and obstructive sleep apnea (lower cAHI/AHI percentage). AHI indicates apnea‐hypopnea index; BMI, body mass index; cAHI, central AHI; CI, confidence interval; LVEF, left ventricular ejection fraction; min, minimum; NYHA, New York Heart Association; pco ₂, partial pressure of carbon dioxide; Sao ₂, oxygen saturation.

Figure 5

Forest plot of risk factors for periodic breathing (defined as Cheyne‐Stokes respiration [CSR] ≥20%). AHI indicates apnea‐hypopnea index; BMI, body mass index; cAHI, central AHI; CI, confidence interval; LVEF, left ventricular ejection fraction; min, minimum; NYHA, New York Heart Association; pco ₂, partial pressure of carbon dioxide; Sao ₂, oxygen saturation.