Vitality and Assure implantable cardioverter defibrillator (ICD) families and Contak Renewal cardiac resynchronisation therapy defibrillator (CRT-D) families 를 위한 안전성 경고 / 현장 안전성 서한

Data from the United Kingdom is current through April 2019. All of the data comes from the Medicines and Healthcare products Regulatory Agency, except for the categories Manufacturer Parent Company and Product Classification.
The Parent Company and the Product Classification were added by ICIJ.
The parent company information is based on 2017 public records. The device classification information comes from FDA’s Product Classification by Review Panel, based on matches of recall data from the U.S. and the United Kingdom.

Delay in delivery of therapy during device middle-of-life phase due to temporarily extended charge time limits.
Transition to device end of life (EOL) without prior observation of elective replacement indication (ERI) even though battery capacity remains available.The MHRA has received 31 reports of early explants from four of the above device models (1870, 1871, 1872, A135) during the middle-of-life (MOL) phase. Replacement has been due to observation of premature elective replacement / end of life indicators (ERI/EOL), caused by long capacitor charge times. The MHRA has also become aware of confusion about ERI/EOL indicators throughout implant duration.Incident reports have included devices displaying:extended charge times where no replacement / end of life indicators have been observed
ERI where charge times have extended beyond 26 seconds giving rise to potentially inappropriate therapy delay for some patients
EOL indicators with charge times in excess of 30 seconds without ERI being observed in the first instance.Boston Scientific ICDs / CRTDs are designed to regularly monitor both battery voltage and capacitor charge time, and flag ERI when specified limits are exceeded. Charge time ERI is flagged whenever two charges (capacitor reform or therapeutic shock) occur within a 24hr period in which both exceed the specified limit.Increase in charge time (due to a rise in battery impedance) is an expected behaviour of ICDs that have lithium-silver-vanadium-oxide batteries. However, early batteries used in some of the above models have a tendency to exhibit a more exaggerated increase in battery impedance during the MOL phase, due to a battery manufacturing anomaly.Boston Scientific has confirmed that the above models have been programmed with temporarily extended ERI charge time limits during the MOL phase (compared to unaffected models). This is to prevent premature tripping of ERI due to the battery impedance characteristic.In January 2007, Boston Scientific issued a product update about this issue via their website. The company issued a more detailed and informative product update about this problem in March 2007.The MHRA is issuing this Medical Device Alert to ensure that all UK clinicians who implant these devices, or manage patients already implanted with these devices, are aware of Boston Scientific’s communication and can therefore consider the clinical implications of long charge times that may be inappropriate for some patients.