Implanted heart device linked to increased survival

June 3, 2014, Duke University Medical Center

Implantable cardioverter defibrillators (ICDs) are associated with improved survival among heart failure patients whose left ventricles only pump 30 to 35 percent of blood out of the heart with each contraction, according to a study from the Duke Clinical Research Institute.

The findings, published in the June 4 issue of the Journal of the American Medical Association, support existing recommendations to implant ICDs in with a left ventricular ejection fraction (LVEF) – a measurement of how much blood is squeezed out of the heart – of 35 percent or lower.

"Our findings fill an important gap in knowledge, as most randomized clinical trials of ICDs include with a median LVEF of well below 30 percent," said Sana Al-Khatib, M.D., MHS, the study's lead investigator and associate professor of medicine at Duke.

"Given that a large number ICDs are implanted in patients with a LVEF between 30 to 35 percent, understanding outcomes in such patients is important."

ICDs are small devices implanted in the chest to monitor the heart's rhythm and deliver small electrical pulses or shocks to help treat life-threatening . Previous have shown that ICDs are the best therapy currently available to prevent sudden cardiac death in patients with heart failure.

The researchers found that survival of heart failure patients with a LVEF of 30 to 35 percent was significantly improved in those with ICDs versus those without ICDs. Three-year mortality rates dropped from 55 percent to 51.4 percent when an ICD was implanted.

Similarly, ICDs were associated with increased survival among heart failure patients with a LVEF of less than 30 percent, with three-year mortality rates dropping from 57.6 percent to 45 percent with ICD use.

Joint guidelines from the American College of Cardiology Foundation and the American Heart Association recommend using ICDs to prevent sudden in select patients with a LVEF of 35 percent or less. The American College of Cardiology defines a normal heart's LVEF as 50 to 70 percent, while a measurement below 50 percent may be a sign of dysfunction or heart failure.

To better understand outcomes among heart failure patients with a LVEF of 30 to 35 percent, the researchers studied the National Cardiovascular Data Registry, intended to track primary prevention ICDs implanted in Medicare beneficiaries, making it the largest repository of ICD implants in the United States. They compared individuals in the registry with patients in the Get With the Guidelines-Heart Failure database who also had a LVEF of 30 to 35 percent but did not have ICDs.

The researchers compared all-cause mortality among those with and without ICDs, looking at a total of 3,120 patients with a LVEF of 30 to 35 percent. The analysis was repeated in 4,578 patients with a LVEF of less than 30 percent.

"Until now, the association between the ICD and improved outcomes in patients with a LVEF of 30 to 35 percent was largely implied," Al-Khatib said. "Our results support current guidelines to implant prophylactic ICDs in patients with a LVEF of 35 percent or lower."

Explore further: Remotely monitoring heart patients with implanted defibrillators lowers risk of death

More information: Paper doi:10.1001/jama.2014.5310

Related Stories

Remotely monitoring heart patients with implanted defibrillators lowers risk of death

May 12, 2014
(Medical Xpress)—Patients with implantable cardioverter defibrillators (ICD) have significantly lower risk of death and re-hospitalization if they are followed through an automatic, wireless remote monitoring system, a ...

Cardiac resynchronization improves survival in heart failure patients

March 31, 2014
Patients in mild heart failure who receive a specialized pacemaker known as cardiac resynchronization therapy with a defibrillator (CRT-D) may live longer than those implanted with a traditional implantable cardioverter defibrillator ...

Elderly benefit from using implantable defibrillators

June 17, 2013
The elderly may benefit from implantable cardioverter defibrillators as much as younger people, according to new research in the American Heart Association journal Circulation.

ICDs can reduce sudden death in young patients with hypertrophic cardiomyopathy

November 5, 2012
A multicenter registry has demonstrated that the use of implantable cardioverter-defibrillators (ICDs) to combat sudden cardiac death in high-risk pediatric patients suffering from hypertrophic cardiomyopathy (HCM). The study ...

Recommended for you

A nanoparticle inhalant for treating heart disease

January 18, 2018
A team of researchers from Italy and Germany has developed a nanoparticle inhalant for treating people suffering from heart disease. In their paper published in the journal Science Translational Medicine, the group describes ...

Starting periods before age of 12 linked to heightened risk of heart disease and stroke

January 15, 2018
Starting periods early—before the age of 12—is linked to a heightened risk of heart disease and stroke in later life, suggests an analysis of data from the UK Biobank study, published online in the journal Heart.

'Decorated' stem cells could offer targeted heart repair

January 10, 2018
Although cardiac stem cell therapy is a promising treatment for heart attack patients, directing the cells to the site of an injury - and getting them to stay there - remains challenging. In a new pilot study using an animal ...

Two simple tests could help to pinpoint cause of stroke

January 10, 2018
Detecting the cause of the deadliest form of stroke could be improved by a simple blood test added alongside a routine brain scan, research suggests.

Exercise is good for the heart, high blood pressure is bad—researchers find out why

January 10, 2018
When the heart is put under stress during exercise, it is considered healthy. Yet stress due to high blood pressure is bad for the heart. Why? And is this always the case? Researchers of the German Centre for Cardiovascular ...

Heart-muscle patches made with human cells improve heart attack recovery

January 10, 2018
Large, human cardiac-muscle patches created in the lab have been tested, for the first time, on large animals in a heart attack model. This clinically relevant approach showed that the patches significantly improved recovery ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.