With around 30% of the US population experiencing symptoms of insomnia, it is no wonder that the use of prescription sleeping pills is common. But for patients with diastolic heart failure, such medication may significantly increase the risk of cardiovascular events. This is according to a study recently presented at the Heart Failure Congress 2014 in Athens, Greece.
Approximately 5.1 million people in the US have heart failure - a condition whereby the heart is unable to pump enough blood and oxygen around the body to support other organs.
The research team, led by Dr. Masahiko Setoguchi of the Social Insurance Central General Hospital in Tokyo, Japan, says that sleeping problems are a common side effect of heart failure.
As a result, many patients are prescribed sleeping pills when they are discharged from the hospital, as well as diuretics, antihypertensives, anticoagulants, antiarrhythmics and antiplatelets.
The more hospitalizations a heart failure patient has, the worse their cardiac function seems to be, according to the researchers. Therefore, they wanted to investigate whether the drugs that patients are prescribed at discharge are associated with hospital readmission and cardiac events.
Review of more than 100 heart failure patients
The researchers reviewed the medical records of 111 heart failure patients who were admitted to the Tokyo Yamate Medical Center in Japan between 2011 and 2013.
Sleeping pills may increase the risk of hospital readmission and cardiovascular-related death for patients with diastolic heart failure, according to researchers.
Data was gathered on the patients' cardiovascular conditions, coexisting medical conditions, medication administered during hospitalization and prescribed at discharge, vital signs at hospital admission and discharge, laboratory test results and information from electrocardiograms (ECGs), echocardiograms and chest radiographs.
Patients were divided into two groups; those with preserved ejection fraction (HFpEF) - referred to as diastolic heart failure - and those with reduced ejection fraction (HFrEF) - referred to as systolic heart failure. Ejection fraction is a measurement of the volume of blood pumped out of the left and right ventricle with each heartbeat.
"Management and prognosis can vary between patients with HFpEF and HFrEF so we analyzed the two groups separately," explains Dr. Setoguchi.
The team followed patients for 180 days after they were discharged from the hospital or until patients reached the "study endpoint" through hospital readmission for heart failure or passing away from cardiovascular causes.
Sleeping pills 'increased risk of hospital readmission and cardiovascular-related death'
The researchers found that during the follow-up period, 15 of 47 HFpEF patients reached study endpoint. On comparing patients who reached study endpoint with those who did not, they found differences in prescription of sleeping pills (benzodiazepine hypnotics), blood sodium levels at hospital admission and blood hemoglobin levels at discharge.
Further investigation revealed that HFpEF patients who were prescribed sleeping pills were eight times more likely to experience hospital readmission for heart failure or suffer cardiovascular-related death, compared with HFpEF patients who were not prescribed sleeping medication.
Commenting on the team's findings, Dr. Setoguchi says:
"The main finding of our study is that HFpEF patients prescribed sleeping pills have an increased risk of cardiovascular events.
The number of HFpEF patients is increasing and becoming a larger proportion of heart failure patients overall. Our results therefore are of growing relevance to heart failure patients and the professionals who treat them."
"Benzodiazepine hypnotics may have cardiodepressant actions," he continues. "They may also exert respiratory depressant actions which could exacerbate sleep disordered breathing and lead to a worse prognosis."
However, Dr. Setoguchi notes that larger studies among HFpEF are needed to confirm the findings, so heart failure patients should not be advised to stop using sleeping medication just yet.
"But HFpEF patients who use sleeping pills, particularly those who have sleep disordered breathing, should be carefully monitored," he adds.
The team found no association between sleeping pills and increased risk of cardiovascular-related death and hospital readmission among HFrEF patients.
However, the team found that HFrEF patients who were prescribed medication for high blood pressure - including ACE (angiotensin-converting enzyme) inhibitors or angiotensin receptor blockers - had less than one quarter the risk of experiencing cardiovascular events, compared with HFrEF patients who were not prescribed high blood pressure medication.
This is not the first time sleeping pills have been linked to health problems. A 2012 study published in the BMJ found that the medication may increase cancer and death risk, even if taken no more than 18 times a year.