FDA Issues Urgent Class I Recall of Boston Scientific Defibrillation Leads After Reports of Deaths and Serious Injuries

September 15, 2025 — Washington, D.C.

The U.S. Food and Drug Administration (FDA) has issued a Class I recall, the most serious type of safety notice, for a series of Boston Scientific defibrillation leads used in implantable cardioverter defibrillators (ICDs). The action follows mounting evidence that certain models are linked to device malfunctions associated with progressively rising shock impedance, resulting in 16 confirmed deaths and 386 serious injuries to date.

The affected leads, including the widely implanted Endotak Reliance and Reliance 4-Front/4-Site models with ePTFE-coated coils, were manufactured and distributed between 2002 and 2021. While Boston Scientific halted production of these coated versions four years ago, the FDA estimates that over 250,000 patients in the United States still have the devices implanted, raising major concerns for long-term safety monitoring.

The Core Issue: Impedance Build-Up in Implanted Leads

According to the FDA, the problem lies in low-voltage shock impedance (LVSI). Over time—often after eight or more years of implantation—the leads may experience calcification or protein buildup around the ePTFE coils. This results in a gradual increase in impedance, which can ultimately prevent the defibrillator from delivering life-saving shocks.

Alarmingly, standard device checks may not always catch the problem in time. Impedance readings can appear within normal ranges, giving physicians and patients false reassurance. In some cases, shocks administered during device testing temporarily reduce impedance, but the issue typically returns within months.

“This is not a problem that can be solved by routine follow-ups alone,” said a member of the Heart Rhythm Society (HRS) advisory panel. “Hospitals must adopt continuous remote monitoring and proactive device analytics to identify these trends before catastrophic failure occurs.”

FDA and HRS Monitoring Recommendations

In response to the recall, the FDA and HRS have published clear monitoring thresholds and clinical guidance:

• Single-coil leads: heightened concern if LVSI exceeds 90 ohms

• Dual-coil leads: heightened concern if LVSI exceeds 70 ohms

• Replacement should be considered if LVSI crosses 150 ohms

Other recommendations include:

• Prioritizing RV− polarity settings to reduce impedance build-up

• Programming shocks to maximum energy in high-risk patients

• Ensuring that remote monitoring systems are active and reviewed regularly

Clinical Impact: A Challenge for Hospitals and Patients

Hospitals and cardiac electrophysiology labs are now tasked with a difficult balancing act. On one hand, lead extraction carries its own risks, particularly for patients with devices implanted for more than a decade. On the other, leaving a malfunctioning lead in place could result in failed defibrillation at a critical moment.

Boston Scientific has advised against blanket removal of all affected leads but recommends case-by-case evaluation, emphasizing the importance of remote data review. Hospitals are urged to audit patient records, flag at-risk individuals, and create contingency plans for rapid lead replacement when necessary.

Patients are also being told to take an active role. The FDA stresses that anyone with a Boston Scientific ICD should:

• Contact their cardiologist to confirm whether their model is affected

• Verify that remote monitoring is active and functioning

• Discuss potential device reprogramming or preventive replacement options

Industry Implications: Renewed Pressure on Device Safety

This high-profile recall has once again placed the spotlight on long-term implantable device safety and post-market surveillance practices. Analysts note that while Boston Scientific discontinued the problematic ePTFE-coated coils in 2021, the persistence of hundreds of thousands of devices in patients underscores the lifelong implications of implantable technology.

“Real-time telemetry and predictive analytics are no longer optional,” noted one FDA advisory panelist. “They must become standard in post-market device management if we want to prevent tragedies like this.”

Looking Ahead

The Boston Scientific defibrillation lead recall is more than just an isolated device issue—it reflects the broader challenges of balancing innovation with long-term patient safety. Hospitals are being urged to move beyond paper-based recalls and adopt systematic monitoring strategies capable of detecting slow-developing failures.

For patients, the message is clear: vigilance and communication with healthcare providers are essential. For manufacturers, this recall serves as a powerful reminder that accountability doesn’t end at the point of sale—it continues for the life of the device inside the patient.