Implantable cardioverter-defibrillator: Encyclopedia II - Implantable cardioverter-defibrillator - Clinical trials

Implantable cardioverter-defibrillator - Clinical trials

A number of clinical trials have demonstrated the superiority of the ICD over AAD (antiarrhythmic drugs) in the prevention of death from malignant arrhythmias. The SCD-HeFT trial (published in 2005) showed a significant all-cause mortality benefit for patients with ICD. Heart Failure patients that were implanted with an ICD had an all-cause death risk 23% lower than placebo and an absolute decrease in mortality of 7.2 percentage points after five years in the overall population.¹ Reporting in 1999, the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial consisted of 1,016 patients, and deaths in those treated with AAD where more frequent (n=122) compared with deaths in the ICD groups (n=80, p < 0.001)[1]

Initially ICDs were implanted via thoracotomy with defibrillator patches applied to the epicardium or pericardium. The device was attached via subcutaneous and transvenous leads to the device contained in a subcutaneous abdominal wall pocket. The device itself acts as an electrode. Most ICDs nowadays are implanted transvenously with the devices placed in the pectoral region similar to pacemakers. Intravascular spring or coil electrodes are used to defibrillate.

Adapted from the Wikipedia article "Clinical trials", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki