Sleep Apnea May Be More Common than Previously Thought in CardioOncology Patients

A new study found the prevalence of sleep apnea in cardiology patients was high and had similar rates in patients with heart failure with reduced ejection fraction (HFpEF) or heart failure with preserved ejection fraction (HFrEF), and the prevalence of sleep apnea in cardio-oncology patients was the same or greater than other risk factors used in risk factor profile algorithms.¹

“Sleep apnea has not been routinely assessed in patients undergoing cancer therapeutics,” wrote investigators, led by Mini K. Das, MD, medical director of the cardio-oncology program at Baptist Health in Louisville, Kentucky. “In our study, it is as prevalent as other traditional risk factors currently utilized in [cardiovascular] risk algorithms.”

The measures of left ventricular ejection fraction (LVEF)—evaluating how well the heart is pumping blood throughout the body—and global longitudinal LV strain (GLS)—assessing how much the cell shrinks to create a force to eject the blood out of the heart—both help predict early cancer therapy-related cardiomyopathy. Risk factors can also predict poor cardiovascular outcomes. A 2022 study found severe sleep apnea in heart failure patients, and they were 2-to-3-fold more likely to experience atrial fibrillation.²

Since sleep apnea causes LV dysfunction, congestive heart failure, and abnormal GLS, investigators wanted to assess the prevalence of sleep apnea in cardiology and cardio-oncology patients.¹

“Echocardiogram has evolved to be a useful tool to detect and therefore treat cardiomyopathy early in patients with sleep apnea and in the cardio-oncology population, so we also wanted to see if there are shared echo markers that identify patients who are at greater risk as they start their journey to treat their cancer,” Das said in a press release.

The study included 296 general cardiology patients and 240 cardio-oncology patients. The team obtained data on traditional cardiovascular risk factors, STOP-BANG score—a questionnaire to screen for obstructive sleep apnea—and history of sleep study and whether they were treated. Just for the cardio-oncology patients, the team collected baseline echo LVEF and GLS results.

Investigators compared the prevalence of traditional risk factors with the prevalence of sleep apnea in both the cardiology group and the cardio-oncology group. Moreover, they compared baseline LVEF and GLS results in patients diagnosed with sleep apnea and low or high STOP-BANG scores for cardio-oncology patients.

General cardiology patients had a sleep apnea prevalence of 54%, and cardio-oncology patients had a sleep prevalence of 35%. Cardio-oncology patients had greater sleep apnea than several traditional risk factors, such obesity (~ 52%), smoking (~ 46%), aflib (~ 33%), diabetes (~ 29%), kidney failure (~ 29%), heart failure (~ 19%), stroke (~18%), and heart attack (~ 11%),

The cardio-oncology group also had a similar LVEF in patients with treated or untreated sleep apnea (5% vs. 10% for EF ≤ 50; 95% vs. 90% for EF ≥ 51) or with high STOP-BANG scores (14% for EF ≤ 50; 86% for EF ≥ 51). In contrast, GLS was significantly abnormal in patients with untreated sleep apnea (35% for GLS ≥ - 17.9) and patients with high STOP-BANG scores (31% for GLS ≥ - 17.9; 69% for GLS ≤ - 18. The abnormal GLS is a common parameter associated with adverse cardiovascular events.

Sleep apnea prevalence in the general cardiology group was similar to patients with HFrEF (52%) or heart failure with preserved ejection fraction (48%).

“We feel that sleep apnea should be added to current risk algorithms and a larger study is needed to assess the impact of sleep apnea and treatment outcomes in this high-risk population,” investigators concluded. “Until then, we feel sleep apnea assessment should be a part of routine risk assessment for patients receiving cancer therapeutics.”

^References

1. ^{Data Shows Significant Prevalence of Sleep Apnea Among Cardio-Oncology Patients. EurekAlert! February 9, 2024. https://www.eurekalert.org/news-releases/1033660. Accessed February 12, 2024.}
2. ^{Butera, A. Sleep Apnea, Atrial Fibrillation Identified in Patients with Heart Failure. HCPLive. May 9, 2022. https://www.hcplive.com/view/sleep-apnea-atrial-fibrillation-heart-failure. Accessed February 12, 2024.}