NEW YORK (Reuters Health) – Implantable cardioverter-defibrillators (ICDs) used to prevent sudden cardiac death in patients with severe left ventricular dysfunction significantly improve survival in younger patients, but not those in their sixties and older, according to the results of a new meta-analysis.

To look into the effectiveness of ICDs in different age groups, Dr. Pasquale Santangeli, at Catholic University of the Sacred Heart in Rome, Italy along with Dr. Luigi Di Biase at the University of Texas, Austin, and colleagues identified five randomized trials of prophylactic ICD verus medical therapy that provided information for different age ranges.

As the researchers explain in the Annals of Internal Medicine for November 2, the primary analysis focussed on the three trials that did not enroll patients early after acute MI. Pooled results showed that ICD therapy in younger patients reduced all-cause mortality compared with medical therapy (HR, 0.65; p=0.001)

However, the survival benefit in elderly patients was smaller and not statistically significant (HR, 0.81; p=0.11), Drs. Santangeli and colleagues found.

Incorporating data from the two trials that included early post-AMI patients produced an HR of 0.97 in elderly patients. Specifically, the authors report,