This communication is part of the Communications Pilot to Enhance the Medical Device Recall Program. The FDA has become aware of a potentially high-risk device issue. The FDA will keep the public informed and update this web page as significant new information becomes available.

Affected Product

The FDA is aware that Boston Scientific has issued a letter notifying affected customers that certain ENDOTAK RELIANCE Defibrillation leads with expanded polytetrafluoroethylene (ePTFE) coated coils may impact shock efficacy and/or require early replacement.

Product Name

 Model

Coil(s) 

Terminal

ENDOTAK RELIANCE

0160

SC

DF-1

ENDOTAK RELIANCE

0161

SC

DF-1

ENDOTAK RELIANCE

0162

SC

DF-1

ENDOTAK RELIANCE

0164

DC

DF-1

ENDOTAK RELIANCE

0165

DC

DF-1

ENDOTAK RELIANCE

0166

DC

DF-1

ENDOTAK RELIANCE

0167

DC

DF-1

ENDOTAK RELIANCE

0170

SC

DF-1

ENDOTAK RELIANCE

0171

SC

DF-1

ENDOTAK RELIANCE

0172

SC

DF-1

ENDOTAK RELIANCE

0173

SC

DF-1

ENDOTAK RELIANCE

0174

DC

DF-1

ENDOTAK RELIANCE

0175

DC

DF-1

ENDOTAK RELIANCE

0176

DC

DF-1

ENDOTAK RELIANCE

0177

DC

DF-1

ENDOTAK RELIANCE

0180

SC

DF-1

ENDOTAK RELIANCE

0181

SC

DF-1

ENDOTAK RELIANCE

0182

SC

DF-1

ENDOTAK RELIANCE

0183

SC

DF-1

ENDOTAK RELIANCE

0184

DC

DF-1

ENDOTAK RELIANCE

0185

DC

DF-1

ENDOTAK RELIANCE

0186

DC

DF-1

ENDOTAK RELIANCE

0187

DC

DF-1

RELIANCE 4-SITE

0282

SC

DF-1

RELIANCE 4-SITE

0283

SC

DF4

RELIANCE 4-SITE

0285

DC

DF4

RELIANCE 4-SITE

0286

DC

DF4

RELIANCE 4-SITE

0292

SC

DF4

RELIANCE 4-SITE

0293

SC

DF4

RELIANCE 4-SITE

0295

DC

DF4

RELIANCE 4-SITE

0296

DC

DF4

RELIANCE 4-FRONT

0657

SC

DF4

RELIANCE 4-FRONT

0658

DC

DF4

RELIANCE 4-FRONT

0682

SC

DF4

RELIANCE 4-FRONT

0653

SC

DF4

RELIANCE 4-FRONT

0685

DC

DF4

RELIANCE 4-FRONT

0686

DC

DF4

RELIANCE 4-FRONT

0692

SC

DF4

RELIANCE 4-FRONT

0693

SC

DF4

RELIANCE 4-FRONT

0695

DC

DF4

RELIANCE 4-FRONT

0696

DC

DF4

What to Do

Continue routine follow-up of defibrillation systems with ePTFE leads and determine the most recent approximate 28-day average low-voltage shock impedance (LVSI) that has not been influenced by the delivery of a shock and review high-voltage shock impedance (HVSI) for all shocks from the most recent episode since the last system check.

  • On July 24, Boston Scientific sent all affected healthcare providers a letter recommending the following actions:
    • Continue routine follow-up of defibrillation systems with ePTFE leads either via in-person or remote monitoring (RM) per labeling or medical guidelines with consideration that RM can facilitate early detection of this pattern.
    • During routine follow-up of affected leads, determine the most recent approximate 28-day average LVSI that has not been influenced by the delivery of a shock and review HVSI for all shocks from the most recent episode since the last system check using the criteria and data provided in the physician letter.
    • If lead replacement is planned, carefully consider the risk/benefit of lead extraction versus abandonment. Based on implant time and likely coil calcification, these leads may pose an increased risk of extraction-related complications.
    • There may be circumstances such as routine defibrillator replacement that merit complex decision making. Contact BSC Technical Services for further assistance if necessary.
    • Distribute the provided letter to all healthcare professionals (HCPs) within your organization who need to be informed and include this letter in the patient’s medical record.
    • A patient letter is available upon request, which can be distributed to the patient.

Check this web page for updates. The FDA is currently reviewing information about this potentially high-risk device issue and will keep the public informed as significant new information becomes available.

Reason for Early Alert

Boston Scientific is aware of the association of calcified defibrillation lead coil(s) with a pattern of gradually rising LVSI measurements. This calcification phenomenon can biologically encapsulate and electrically insulate the defibrillation lead coil(s).

BSC has completed a comprehensive investigation of ePTFE RELIANCE lead performance to identify the early signs of this phenomenon, characterize its potential effect on shock efficacy, and provide recommendations to mitigate the associated risk. Details of this investigation are described within Appendix A of the physician letter. Key findings include:

  • While cracking of calcified ePTFE coating has been observed, calcification of the shock coil(s) does not compromise the physical or electrical integrity of the lead.
  • A trend of gradually rising LVSI is correlated with shock coil calcification and is more prevalent with BSC RELIANCE ePTFE defibrillation leads compared to non-ePTFE defibrillation leads from BSC and other manufacturers; leads may be implanted for eight or more years prior to manifestation of this trend.
  • The shock coil encapsulant material may exhibit a polarity bias with Reversed (RV+) polarity having an elevated high voltage shock impedance (HVSI) relative to Initial (RV-) polarity7. Reversed (RV+) polarity shocks are 4.5 times more likely to initiate a high, delivered shock impedance alert (Code-1005), and defibrillation systems programmed to Reversed (RV+) polarity exhibiting a gradual rising LVSI have a lower defibrillator-determined shock success rate.
  • When managing leads with calcified coil(s), delivery of commanded shocks is neither effective at permanently mitigating rising impedance risk nor predictive of future impedance as LVSI may initially decrease but typically returns to pre-shock values in less than six months.

The most common harm is early lead replacement, and the most serious harm is death or need for cardiac resuscitation due to non-conversion of a sustained ventricular arrhythmia from a reduced shock energy due to high impedance.

As of July 24, Boston Scientific has reported 386 serious injuries and 16 patient deaths associated with this issue.

Device Use

Boston Scientific ENDOTAK RELIANCE leads are intended for pacing, rate-sensing, and delivery of cardioversion and defibrillation shocks when used with a compatible pulse generator.

Contact Information

Customers in the U.S. with adverse reactions, quality problems, or questions about this recall should contact Boston Scientific at tech.services@bsci.com or 1-800-227-3422.

Unique Device Identifier (UDI)

The unique device identifier (UDI) helps identify individual medical devices sold in the United States from manufacturing through distribution to patient use. The UDI allows for more accurate reporting, reviewing, and analyzing of adverse event reports so that devices can be identified, and problems potentially corrected more quickly.

How do I report a problem?

Health care professionals and consumers may report adverse reactions or quality problems they experienced using these devices to MedWatch: The FDA Safety Information and Adverse Event Reporting Program.

  • Content current as of:

    08/06/2025

Source