FRIDAY, Sept. 17 (HealthDay News) -- The U.S. Food and Drug
Administration has approved a new use for three cardiac
resychronization therapy defibrillators (CRT-D) to treat people
with a heart abnormality called left bundle branch block who also
have mild cases of heart failure or heart failure with no
The devices are all made by Boston Scientific Corp. As CRT-D
devices, they combine the ability to shock an abnormally beating
heart back to its normal rhythm, and the ability to improve
coordination of the heart's left and right ventricles as they pump
blood through the body.
In people with left bundle branch block, activation of the left
ventricle is delayed, causing it to beat out of step with the
heart's right ventricle.
In a news release, the FDA said the new approval was based on
results from an 1,820-person, three-year study that found among
people with left bundle branch block, the CRT-D devices reduced the
risk of death by 57 percent, compared to those fitted with a
standard implanted defibrillator.
CRT-Ds are to be used in addition to heart failure drug therapy,
not as a replacement for it, the agency warned.
As a condition of approval, the FDA said it is requiring Boston
Scientific to conduct two long-term studies of the devices.
The FDA has more about