Boston Scientific (NYSE:BSX) is warning healthcare providers that patients implanted with certain of its older Emblem S-ICD cardioverter defibrillators may need early revision surgery due to premature battery depletion.
The company expanded on an August 2019 advisory about 350 of its Emblem S-ICD models A209 and A219 to include approximately 38,350 active devices. The devices contain a low-voltage capacitor that may cause their batteries to drain too quickly. A company analysis of returned devices indicates that at least three months of battery capacity remain before the battery runs out.
The issue does not affect models distributed after August 2018, when the company included a different low-voltage capacitor that has not exhibited this depletion behavior. No serious injuries or deaths have been reported, according to the company.
The notice was one of three that Boston Scientific issued together, as some patients may be affected by all three, the company said.
The second notice warned physicians that approximately 47,000 Emblem S-ICD1 subcutaneous electrodes (model 3501) may fracture. Boston Scientific said it has received 27 reports of electrode body fractures at a location just distal to the proximal sense ring in devices distributed worldwide since 2017. One patient died, the company said.
Such fractures may lead to “inappropriate shock therapy (IAS) in select programmed sense configurations,” the company said. If high-voltage conductors fracture, an electrode will be unable to deliver defibrillation therapy and a high impedance alert will go off. The likelihood of potential for life-threatening harm is 1 in 25,000 (0.004%) at 10 years, according to the advisory.
In its third advisory, Boston Scientific notified physicians that 3,350 Emblem S-ICD model A209 and A219 devices may exhibit electrical overstress while delivering high-voltage therapy. Variations in header assembly may allow a “very small pathway” to develop, allowing moisture to penetrate the device and cause it to short out during high-voltage therapy, the warning said.
Boston Scientific said it has confirmed six events of such electrical overstress, with the most common clinical outcome being early device replacement. No serious injuries were reported, the company said.
The advisories provided guidance for physicians whose patients have the implants affected by any of the three advisories. None of the affected devices are still available for sale, the company said.
“Boston Scientific voluntarily issued these product advisories for the Emblem Subcutaneous Implantable Cardioverter Defibrillator (S-ICD) System,” the company said in an email to MassDevice. “No products are being removed from the market. The advisories do not require any new action from most patients who already have the device implanted, as device performance can be assessed through regularly scheduled doctor visits and, in most instances, can be monitored remotely. For a small number of impacted patients, we recommend an earlier-than-planned follow-up appointment, which will be communicated to them directly by their healthcare provider.”
This article has been updated to include comments from Boston Scientific.