The FDA approved on 16 September 2010 a new indication for three cardiac resynchronisation therapy defibrillators (CRT-D) used to treat certain heart failure patients. The new use is for patients with left bundle branch block. The three devices, all manufactured by Boston Scientific, are intended to treat patients with left bundle branch block who have either mild heart failure or heart failure with no apparent symptoms.
“This approval allows heart failure patients with left bundle branch block to benefit from this therapy,” said Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health. “The FDA is pleased to safely make this new technology available for a greater number of heart failure patients.”
The FDA based its approval on the results of the 1,820-patient MADIT-CRT (Multicenter automatic defibrillator implantation trial with cardiac resynchronization therapy) clinical study. The study followed 1,820 patients for an average of nearly three years at 110 centres in the United States, Europe, Canada, and Israel. It compared CRT-D therapy to ICD-only therapy in specific heart failure patients to determine whether it reduced the risk of death and heart failure. In patients with left bundle branch block, who represented 70% of the study group, CRT-D showed a reduction in the risk of death and heart failure by 57%, as compared to ICD alone.
The rate of complications was considered to be acceptable by the FDA for this device; however, physicians should adequately inform patients about potential complications.
The exclusive expanded indication is effective immediately and makes Boston Scientific CRT-Ds the only devices approved by the FDA for patients in all New York Heart Association (NYHA) classes of heart failure. The company’s CRT-Ds had previously been approved for NYHA class III and IV patients. The expanded indication approves Boston Scientific CRT-Ds for use in high risk NYHA class I and II patients with left bundle branch block.
As a condition of FDA approval, Boston Scientific must conduct two post-approval studies. One study will evaluate complications and long-term mortality benefits of CRT-D in patients with left bundle branch block identified through the National Cardiovascular Data Registry. The other will follow patients from the original MADIT-CRT clinical study every six months for five years to assess long-term mortality benefits of CRT-D vs. ICD.
