Sleep apnea may be prevalent among patients who are at higher risk of developing congestive heart failure from cancer therapy, according to new findings presented by Das et al at the American College of Cardiology (ACC) Advancing the Cardiovascular Care of the Oncology Patient course.
Background
Sleep apnea—a disorder involving altered breathing during sleep—consists of either obstructive or central sleep apnea. Both types can be treated to alleviate symptoms and improve cardiovascular outcomes.
A well-established screening tool for detecting sleep apnea is a questionnaire that utilizes eight questions regarding snoring, tiredness, observed apnea, pressure-elevated blood pressure, body mass index, age, the neck, and gender to form the STOP-BANG acronym. Patients are scored based on their yes or no responses with a range from 0 to 8. A score > 3 indicates a high sensitivity for detecting moderate and severe obstructive sleep apnea.
About 48% to 52% of patients with heart failure in the general population may have obstructive sleep apnea, which is associated with a heightened risk of cardiovascular morbidity and mortality. Previous research has determined that left ventricular ejection fraction and left ventricular global longitudinal strain can predict early cancer therapy–related cardiomyopathy. Obstructive sleep apnea has also been linked to left ventricular dysfunction, congestive heart failure, and abnormal left ventricular global longitudinal strain.
Heart failure with reduced ejection fraction and heart failure with preserved ejection fraction are the two most common types of heart failure that signify the heart may be too weak to pump properly or too stiff to fill properly with blood, respectively.
While patients with cancer may have a higher risk of congestive heart failure from cancer therapy, there is currently no data on the prevalence of sleep apnea within this patient population.
Study Methods and Results
In the new study, the researchers used the STOP-BANG questionnaire to assess the prevalence of sleep apnea among 218 patients with cancer and 296 patients without cancer. The researchers collected information on the patients’ traditional risk factors, STOP-BANG scores, and history of sleep. Baseline echocardiogram left ventricular ejection fraction and global longitudinal strain results were measured in the patients with cancer.
“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 echocardiogram markers that identify patients who are at greater risk as they start their journey to treat their cancer,” explained lead study author Mini K. Das, MD, Medical Director of the Cardio-Oncology Program at Baptist Health in Louisville.
The researchers discovered that the incidence of sleep apnea was 39% among the patients with cancer compared with 54% among the patients without cancer. They noted that the prevalence of sleep apnea within the noncancer group was similar to reported rates in patients with heart failure with reduced ejection fraction (52%) or heart failure with preserved ejection fraction (48%).
According to the STOP-BANG scores, the patients with untreated sleep apnea and those who were at higher risk for sleep apnea had abnormal baseline left ventricular strain, a common echocardiogram parameter linked to adverse cardiovascular events.
Conclusions
“Identifying these [patients] may allow early intervention in a risk factor clearly associated with heart failure now recognized to affect cancer therapy and survivorship,” Dr. Das emphasized.
The prevalence of sleep apnea in the patients with cancer was equal to or greater than other traditional risk factors that are currently used in risk factor profile algorithms. Even with a normal left ventricular ejection fraction, the status and severity of sleep apnea was associated with abnormal left ventricular strain. The researchers revealed that the left ventricular global longitudinal strain was more abnormal in the patients with untreated sleep apnea or high STOP-BANG scores.
“Sleep apnea should be incorporated into current risk algorithms, and a larger study is needed to evaluate the impact of sleep apnea in this high-risk population. We feel that sleep apnea assessment must be a part of routine risk assessment for patients undergoing cancer therapeutics,” concluded Dr. Das.
Disclosure: For full disclosures of the study authors, visit acc.org.
