UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has issued a medical device alert (MDA) relating to Medtronic’s EnTrust Implantable Cardioverter/Defibrillator (ICD). The problem relates to a number of occasions on which rapid battery depletion has occurred after the elective replacement indicator (ERI) has been reached, approximately 2.5 years after implantation.
According to the MDA approximately 69,000 EnTrust devices have been sold worldwide since 2005, with just over 1,000 sold in the UK. To date only 0.15% of single chamber EnTrust ICDs and 0.04% of dual chamber EnTrust ICDs worldwide are reported to have experienced rapid voltage decline. Although the issue does not appear to affect devices implanted for less than 30 months, the failure rate as implant duration increases is as yet unknown.
The rapid voltage drop has been linked to an internal short circuit within the ICD battery. Although the exact root cause is still being investigated by the manufacturer, the issue appears to be specific to EnTrust devices. Failure rate data for other Medtronic ICD models incorporating the same battery model currently indicate that they are not affected. Furthermore, these batteries are not used by other manufacturers.
Model numbers affected
D153ATG, D153DRG, D153VRC,
D154ATG, D154DRG, and D154VRC
The MDA requires that all cardiologists and cardiac physiologists who manage patients implanted with ICDs are made aware of the MDA. Needless to say, follow-up for all patients with EnTrust ICDs is being demanded on an urgent basis, with the following guidelines:
- Follow-up within 1 month if the device has been implanted for more than 28 months;
- Follow-up within 3 months in other cases in order to:
- ensure audible alerts for ‘Low Battery Voltage ERI’ and ‘Excessive Charge Time EOL’ are programmed ON (status can be viewed over CareLink)
- advise patients to contact centres immediately if the alert sounds
- compare battery voltage with values from previous follow ups for evidence of rapid battery voltage drop
- Replace ICDs where ERI has been reached in the presence of rapid battery voltage drop, within 2 weeks.
- Continue to review all patients every 3 months.
- Ensure all patients are enrolled on CareLink, in discussion with the manufacturer.
- Prophylactic replacement of these devices is not recommended except in exceptional circumstances.
The full MDA can be found here.