Implanted heart device linked to increased survival

June 3, 2014

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

Could aggressive blood pressure treatments lead to kidney damage?

July 18, 2017
Aggressive combination treatments for high blood pressure that are intended to protect the kidneys may actually be damaging the organs, new research from the University of Virginia School of Medicine suggests.

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Concerns over side effects of statins stopping stroke survivors taking medication

July 17, 2017
Negative media coverage of the side effects associated with taking statins, and patients' own experiences of taking the drugs, are among the reasons cited by stroke survivors and their carers for stopping taking potentially ...

Study discovers anticoagulant drugs are being prescribed against safety advice

July 17, 2017
A study by researchers at the University of Birmingham has shown that GPs are prescribing anticoagulants to patients with an irregular heartbeat against official safety advice.

Protein may protect against heart attack

July 14, 2017
DDK3 could be used as a new therapy to stop the build-up of fatty material inside the arteries

Heart study finds faulty link between biomarkers and clinical outcomes

July 14, 2017
Surrogate endpoints (biomarkers), which are routinely used in clinical research to test new drugs, should not be trusted as the ultimate measure to approve new health interventions in cardiovascular medicine, according to ...

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.