Boston Scientific rebuts HeartRhythm's cardiac resynchronization therapy defibrillator implantation article

Feb 11 2010

Boston Scientific Corporation (NYSE: BSX) today rebutted an article published in the journal HeartRhythm.  The article reported a case summary of a patient who had been implanted subcutaneously with a Cognis cardiac resynchronization therapy defibrillator.  The article suggested a weakened header bond was responsible for the abnormal sensing and pacing impedance experienced by the patient.

The Company issued the following statement:

"We find it unacceptable that HeartRhythm rushed this manuscript to publication and speculated on the cause of the problem without requesting from us a detailed engineering analysis of the explanted device.  Our analysis found that while the bond between the header and the case was weakened, the device functioned normally and a weakened header bond was not the cause of the abnormal sensing and pacing impedance observed in this patient.

"X-ray analysis and electrical testing verified that the header wires were neither fractured nor otherwise damaged, and the seal between the header and the case was secure with no evidence of body fluid under the header.  In short, there is no mechanism to link the noise observations to a weakened header bond.

"Noise observations during the initial implant were not header-related.  In fact, the authors themselves stated: 'It is possible that the initial noise observed on the RV pace/sense channel was due to an RV lead abnormality and not to the header abnormality.'  None of the leads implanted in the patient were manufactured by Boston Scientific.    

"Including this most recent case, only three instances of weakened header bonds have been observed in a context of more than 90,000 COGNIS and TELIGEN devices implanted subcutaneously.  The overall rate of events for this device family compares very favorably to the performance of similar devices and is well within accepted performance ranges.  

"We have implemented manufacturing process improvements to strengthen the header bond on these devices, allowing physicians to implant devices in either a subpectoral or subcutaneous position.  We have received approval from U.S. and European regulatory authorities for the devices with the strengthened header bond and have been shipping these devices.  We expect to complete the transition to these devices by next month."