Sleep apnea in heart failure: Women face higher hospitalization risks

By Dr. Chinta SidharthanReviewed by Benedette Cuffari, M.Sc.Mar 4 2024

In a recent study published in the Journal of the American Heart Association, researchers identify sex-associated patterns associated with the risk of cardiovascular outcomes in heart failure patients with central or obstructive sleep apnea.

Study: Association of Sex With Cardiovascular Outcomes in Heart Failure Patients With Obstructive or Central Sleep Apnea. Image Credit: Andrey Popov / Shutterstock.com

Heart failure and sleep apnea

Heart failure is associated with a significant health and financial burden, in addition to increasing the probability of frequent hospitalizations and death. Importantly, several other medical conditions associated with heart failure also affect the patient’s quality of life.

Sleep apnea, for example, is experienced by over 50% of heart failure patients. Most heart failure patients have either obstructive or central sleep apnea that is often not correctly diagnosed or treated.

While central sleep apnea is not prevalent among the general population, it has a high incidence rate among patients with heart failure. Comparatively, obstructive sleep apnea is not uncommon in the general population, with an incidence rate of 6-17%.

Obstructive sleep apnea is associated with specific sex-associated patterns, with about 23.4% of women experiencing sleep apnea ranging from moderate to severe, whereas the incidence of this condition is higher among men at 49.7%.

Obstructive sleep apnea also results in systemic inflammation, increased oxidative stress, high blood pressure, and increased transmural pressure in the left atrium and ventricle, which increases the risk of cardiac outcomes. However, sex-based differences in the risk of cardiac outcomes due to sleep apnea in heart patients remain unclear.

About the study

Patients hospitalized due to heart failure at the Chinese Academy of Medical Sciences hospital were included in the current study to determine the association between cardiovascular outcomes and different types of sleep apnea. All study participants were 18 or older and underwent sleep studies involving nocturnal sleep monitoring.

Echocardiography results and elevated levels of natriuretic peptides were used to define heart failure. The ejection fraction from the left ventricle was used to categorize heart failure as heart failure with reduced, midrange, or preserved ejection fraction.

Demographic information such as sex and gender, as well as vital measurements, including heart rate and blood pressure, were obtained for all study participants. Electronic health records also provided detailed information on comorbidities,

Fasting blood samples were collected from all patients during their hospitalization. These blood samples were used for a wide range of laboratory tests, including blood gas, blood chemistry, testing for myocardial biomarkers, glycosylated hemoglobin tests, and liver and kidney function tests. Various cholesterol tests were also performed, including total, high-density lipoprotein (HDL), and LDL cholesterol tests.

Overnight sleep monitoring was conducted using a portable cardiorespiratory sleep monitoring machine that records movements in the chest and abdomen, nasal airflow, heart rate, snoring episodes, and pulse oximetry. Study participants attended follow-up visits every three months after hospital discharge for up to one year, followed by visits every six months.

Data on cardiovascular outcomes were obtained from telephonic follow-up visits, records of clinical visits, and medical records. Unplanned hospitalization due to worsening of heart failure or cardiovascular death were the primary outcomes.

Study findings

While the prevalence of obstructive and central sleep apnea was not significantly different between males and females, cardiovascular outcomes such as rehospitalization for heart failure were higher among female heart failure patients with obstructive sleep apnea.

Obstructive sleep apnea was associated with an increased incidence of primary outcomes in female heart failure patients, whereas central sleep apnea did not exhibit these associations. The risk of cardiovascular outcomes associated with central sleep apnea was similar for male and female heart failure patients.

Obstructive sleep apnea was also associated with a greater risk of rehospitalization for heart failure among female patients. In male heart failure patients, obstructive sleep apnea was associated with an increased risk of cardiovascular death.

Conclusions

The study findings indicate that obstructive sleep apnea in patients with heart failure was associated with sex-associated differences in the risk of cardiovascular outcomes. More specifically, female heart failure patients with obstructive sleep apnea had a higher risk of rehospitalization than male patients.

Central sleep apnea was not associated with sex-associated differences in cardiovascular outcomes. However, the incidence of rehospitalization due to heart failure was higher among female heart failure patients with sleep apnea. In comparison, male patients with sleep apnea had a higher incidence of cardiovascular death.