The Food and Drug Administration, has approved a new indication for three cardiac resynchronization therapy defibrillators.
The devices, also called CRT-Ds, are now approved for use in patients with heart failure and left-bundle branch block, which occurs when there is delayed activation and contraction of the left ventricle. All three devices are manufactured by Boston Scientific.
CRT-Ds combine the function of an implantable cardioverter defibrillator (ICD) with cardiac resynchronization therapy, sending small electrical impulses to coordinate contraction of the left and right ventricles. The devices are used together with drug therapy and are not meant to replace that therapy.
The FDA based its Sept. 16 approval on the results of the multinational Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) study, which followed 1,820 patients for an average of 3 years. In patients with left-bundle branch block, a CRT-D decreased the risk of heart failure or death by 57%, compared with ICD alone.
As a condition of approval, the FDA required Boston Scientific to undertake two postapproval studies to assess complications and long-term mortality in patients using the devices.