Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Implantable Cardiac Defibrillator Use Significantly Lowers Heart Failure Mortality

09.03.2004


The use of an implantable cardiac defibrillator (ICD) can provide a significant reduction in mortality in heart failure patients, according to a study coordinated by researchers from the Duke Clinical Research Institute.



"Treatment using conventional therapy plus an implantable cardiac defibrillator showed a statistically significant reduction in total mortality when compared to standard treatment with a placebo and standard treatment with amiodarone, an anti-arrhythmia drug," said Kerry L. Lee, Ph.D., an associate professor of biostatistics at Duke and principal investigator of the data coordinating center of the trial.

Results of the trial, called SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial), were presented today (March 8, 2004) at the American College of Cardiology scientific sessions. The trial was sponsored by the National Heart, Lung and Blood Institute (NHLBI). Medtronic, Inc., Minneapolis, supplied the ICDs and Wyeth Pharmaceuticals, Madison, N.J., supplied the amiodarone and placebo pills. Lee has no financial interests in either company.


Currently, more than 5 million Americans suffer from congestive heart failure (CHF), with more than 400,000 new cases diagnosed annually. CHF is a condition of decreased or impaired function of the heart muscle resulting in an inability to pump sufficient blood through the body. Patients with CHF also have a higher risk of abnormal heart rhythm, known as arrhythmia, which often leads to sudden cardiac death. About half of all CHF patients who die do so from sudden cardiac death.

"With the population growing older, chronic heart failure will become a much more significant problem in the United States," Lee noted.

Traditionally, CHF is treated with ACE inhibitors, beta blockers, diuretics, statins and aspirin to improve the heart’s efficiency. This study’s goal was to determine whether adding a cardiac defibrillator or anti-arrhythmia medication to standard therapies could reduce the risk of sudden cardiac death. An ICD is a small device implanted beneath the skin which corrects abnormal heart rhythms when they occur by providing a controlled electrical impulse to the heart.

In the study, 2,521 patients were enrolled in 148 centers, including Duke, in the United States, Canada and New Zealand. All participants had been diagnosed with moderate to severe CHF, otherwise known as Class II and Class III, according to the New York Heart Association classification system for heart failure. Seventy-seven percent of participants were men, with minorities making up 23 percent of the total. Study participants ranged in age from 19 to 90, with the median age being 60.

Most participants were receiving multiple drugs to treat their CHF. 85 percent were receiving ACE inhibitors; 70 percent digoxin; 69 percent beta blockers; 56 percent aspirin; 38 percent statins; 34 percent warfarin; and 14 percent angiotensin II receptor blocker (ARB).

Participants were randomly entered into three study arms in equal proportions: conventional therapy plus a placebo; conventional therapy plus amiodarone; and conventional therapy plus ICD. The drug arms of the trial were double-blinded so that neither the patient nor the medical providers knew who were receiving placebo or amiodarone. Patients were enrolled from September 1997 through July 2001 and were followed until October 2003.

"What we found was that patients with the ICD had a three-year mortality rate of 17.1 percent compared to 22.4 percent for those receiving placebo and 24 percent for those receiving amiodarone," Lee said. "After five years, the mortality for the ICD patients was 28.9 percent while the amiodarone patients had a 34 percent mortality rate and the placebo patients 36.1 percent.

"It is a significant achievement any time you can find a reduction in mortality of that amount," Lee continued.

When the study ended, 666 participants had died: 182 (22 percent) in the ICD group, 240 (28 percent) in the amiodarone group and 244 (29 percent) in the placebo group.

Lee noted that Class II CHF patients achieved the most significant reduction in mortality from the ICD therapy as compared to the Class III patients.

"It seemed that the more severe the case of heart failure, the more likely the patient died from causes other than arrhythmias which aren’t helped by an ICD," Lee explained.

Lee also noted that the ICD reduced deaths equally for patients whose CHF resulted from heart attack, or ischemia, (52 percent of patients in the trial)and for those patients whose heart failure was due to non-ischemic causes, such as hypertension or a virus.

Duke served as the data-coordinating center for the trial. The study director was Gust H. Bardy, M.D., of the Seattle Institute for Cardiac Research, which served as the clinical coordinating center. Other study leaders were Daniel B. Mark, M.D., from Duke; and Robin Boineau, M.D., and Michael Domanski, M.D., of the NHLBI.

Richard Puff | dukemed news
Further information:
http://dukemednews.org/news/article.php?id=7453

More articles from Health and Medicine:

nachricht Routing gene therapy directly into the brain
07.12.2017 | Boston Children's Hospital

nachricht New Hope for Cancer Therapies: Targeted Monitoring may help Improve Tumor Treatment
01.12.2017 | Berliner Institut für Gesundheitsforschung / Berlin Institute of Health (BIH)

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Midwife and signpost for photons

11.12.2017 | Physics and Astronomy

How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas

11.12.2017 | Earth Sciences

PhoxTroT: Optical Interconnect Technologies Revolutionized Data Centers and HPC Systems

11.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>