In a recent study published within the Journal of the American Heart Association, researchers discover sex-associated patterns related to the danger 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 related to a major health and financial burden, along with increasing the probability of frequent hospitalizations and death. Importantly, several other medical conditions related to heart failure also affect the patient’s quality of life.

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

While central sleep apnea will not be prevalent amongst the final population, it has a high incidence rate amongst patients with heart failure. Comparatively, obstructive sleep apnea will not be unusual in the final population, with an incidence rate of 6-17%.

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

Obstructive sleep apnea also leads to systemic inflammation, increased oxidative stress, hypertension, and increased transmural pressure within the left atrium and ventricle, which increases the danger of cardiac outcomes. Nevertheless, sex-based differences in the danger of cardiac outcomes as a result of sleep apnea in heart patients remain unclear.

Concerning the study

Patients hospitalized as a result of heart failure on the Chinese Academy of Medical Sciences hospital were included in the present study to find out the association between cardiovascular outcomes and several 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 reminiscent of sex and gender, in addition to 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 selection 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 conveyable cardiorespiratory sleep monitoring machine that records movements within 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 1 yr, 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 as a result of worsening of heart failure or cardiovascular death were the first outcomes.

Study findings

While the prevalence of obstructive and central sleep apnea was not significantly different between men and women, cardiovascular outcomes reminiscent of rehospitalization for heart failure were higher amongst female heart failure patients with obstructive sleep apnea.

Obstructive sleep apnea was related to an increased incidence of primary outcomes in female heart failure patients, whereas central sleep apnea didn’t exhibit these associations. The chance of cardiovascular outcomes related to central sleep apnea was similar for female and male heart failure patients.

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

Conclusions

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

Central sleep apnea was not related to sex-associated differences in cardiovascular outcomes. Nevertheless, the incidence of rehospitalization as a result of heart failure was higher amongst female heart failure patients with sleep apnea. Compared, male patients with sleep apnea had a better incidence of cardiovascular death.