Implants Protect People With Heart Failure
Advanced Pacemakers, ICDs Reduce Risk of Death for Those With Heart Failure
ICDs Reduce Sudden Death Risks
In the second study, researchers looked at whether an implantable defibrillator was useful as a primary prevention tool in people with a form of heart failure known as nonischemic cardiomyopathy. This type of heart failure is not caused by coronary artery disease or hardening of the arteries and commonly causes sudden death due to an irregular heartbeat.
Researchers say treatment with drugs such as ACE inhibitors and beta-blockers has been shown to prolong the lives of people with this type of heart failure, but these people are still at risk for sudden death due to heartbeat irregularities.
ICDs have been used as a preventive measure to protect against sudden death in people who have already experienced cardiac arrest or rapid and irregular heartbeats, but researchers say that this was the first large-scale study to look at whether defibrillators might also provide benefits in preventing sudden death in people with this type of heart failure.
In the study, researchers randomly assigned 458 people with this type of heart failure to receive standard drug therapy or drug therapy plus an ICD. The participants were then followed for nearly two-and-a-half years.
During that time, 68 deaths occurred, but only 28 of them occurred in the ICD group compared with 40 in the standard therapy group. Seventeen of the deaths were sudden deaths caused by an irregular heartbeat: three in the ICD group and 14 in the drug therapy group.
Based on those results, researchers say it's too soon to recommend routine implantation of ICDs in all people with heart failure not related to coronary artery disease. But the apparent benefit of the devices in certain subgroups suggests that use of these devices should be considered on a case-by-case basis.
Valuable Information, but Proceed With Caution
In an editorial that accompanies the study, Joseph G. Rogers, MD, and Michael E. Cain, MD, of Washington University School of Medicine, say these studies add critical new information about the use of the new generation of advanced pacemakers and implantable defibrillators to prevent future complications.
They say that until now, trials evaluating this approach have been small and evaluated the quality of life, exercise performance, and other heart performance factors. This new data on their health benefits in reducing illness and death is needed as doctors begin to use these relatively expensive therapies in a larger group of patients.