Implantable Defibrillators Improving Heart Care

Arrhythmia related home cardiac arrests reduced by implantable defibrillator use

(RxWiki News) Patients with heart arrhythmias are at a higher risk of potentially fatal heart attacks. In a recent study, fewer patients have reported out-of-hospital cardiac arrest. Does this suggest modern treatments are working?

Dutch researchers have linked a 10-year decline in out-of-hospital cardiac arrest to increased use of implantable cardioverter-defibrillators (ICDs).  ICDs detect heart rhythm abnormalities and deliver a shock of electricity to the heart, correcting the abnormal heartbeat.

These research investigators estimate that the ICD shocks produced a 33 percent decline in heart attacks.

"Discuss arrhythmia treatment options with a cardiologist."

During the study, Michiel Hulleman, MSc, a lead researcher from the Academic Medical Center in Amsterdam, reviewed data from the Amsterdam Resuscitation Studies (ARREST) between 2005 and 2008. Patients included were those that experienced out-of-hospital cardiac arrest that resulted from a heart arrhythmia. The data was compared to previous studies that encompassed 1995 through 1997.

Researchers interviewed ICD patients, identified appropriate shocks that occurred from 2005 to 2008, and calculated the number of out-of-hospital cardiac arrests caused by severe abnormal heart rhythm.

They used the appropriate shocks to determine which potentially resulted in avoided resuscitation.

From 1995 to 2008, the incidence of out-of-hospital cardiac arrest related to arrhythmia declined from 21 per 100,000 individuals to 17 for every 100,000 patients.

Non-arrhythmia-related out-of-hospital cardiac arrest also decreased during that same period -- from 19 per 100,000 individuals to 12 out of 100,000.

Between 2005 and 2008, 1,972 ICD patients received shocks. Of those, 339 were found to have been caused by a life-threatening arrhythmia. During that period fewer patients also were found to have an abnormal cardiac rhythm -- from 63 percent in 1995 to 47 percent 13 years later.

In an accompanying editorial, Leonard Ilkhanoff, MD, MS, and Jeffrey J. Goldberger, MD, MBA, from Northwestern University Feinberg School of Medicine, noted that the study emphasizes the need for continuous efforts to improve response to out-of-hospital cardiac arrests.

"Although many assumptions are made in this report, any one of which could affect the results, the sensitivity analyses as well as concordance with other data suggest that these estimates have substantial validity," they wrote.

"This validity enables us to use these important data to provide a global perspective on the tremendous efforts that have been put forth during the past several decades on prevention of (sudden cardiac death.)"

Dr. Goldberger works for a non-profit think tank that has received unrestricted education grants from Medtronic, Boston Scientific, and St. Jude Medical, and honoraria from Medtronic, Biotronik and St. Jude Medical. Dr. Ilkhanoff has received honoraria from Biotronik and St. Jude Medical.

The study was recently published in American Heart Association journal Circulation.

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Review Date: 
October 26, 2012