Dive Brief:

• FDA has categorized another recently identified problem with Boston Scientific's Emblem subcutaneous implantable cardioverter defibrillator (S-ICD) system as a Class I recall.

• Boston Scientific issued three field safety notices about the device late last year. FDA earlier this month put one of the faults in Class I, the most serious recall category. Now, the agency has assigned another of the problems to Class I.

• The new FDA notice covers a fault that allows moisture to enter the medical device, causing it to short circuit when it tries to shock the patient. Boston Scientific is yet to receive reports of injuries or deaths linked to the problem but FDA is still treating it as a Class I recall.

Dive Insight:

Early in February, FDA issued a Class I recall notice about the risk of the electrode body fracturing in some Emblem S-ICD products, which physicians implant to prevent sudden cardiac death. At that time, Boston Scientific had received 27 reports about the fault affecting some of the 47,000 devices it had distributed since 2017. One patient died. The other 26 patients suffered serious injuries. 

Boston Scientific disclosed the fault late last year in a statement that also featured two other field safety notices. One of the other field safety notices described six reports of "electrical overstress following delivery of high voltage therapy." In other words, the devices short-circuited. 

Devices with the fault may deliver a smaller shock than intended or fail to deliver a shock at all. If a patient with a faulty device has a cardiac arrest, they could suffer serious injuries or die because the implant fails to deliver the shock their heart needs. That remains a theoretical risk — no patients have been hurt — but one FDA sees as serious enough to treat the fault as a Class I recall. 

The fault affects a subset of around 3,350 EMBLEM S-ICDs that were manufactured with variations in the header assembly between May 2015 and December 2017. Those variations result in "a very small pathway ... that allows moisture ingress, enabling a shorting condition to occur during delivery of high voltage therapy," Boston Scientific wrote in its field safety notice.

None of the affected devices are still available for implant but there are patients living with products prone to the problem. Boston Scientific, in messaging repeated by FDA, asked physicians to discuss the fault with their patients within six weeks. Physicians should more closely monitor the patients but Boston Scientific is advising against routine replacement of the devices.