MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION ENDOTAK RELIANCE SG; IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (NON-CRT)

Model Number	0181
Medical Device Problem Code	High impedance (1291)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	09/15/2025
Type of Reportable Event	Malfunction
Event or Problem Description
It was reported that this right ventricular (rv) lead has exhibited gradually increasing shock impedance measurements, with the most recent value being out-of-range (140 ohms).Boston scientific technical services (ts) was contacted and is pending a data review prior to a potential lead revision procedure.At this time, the rv lead remains implanted and in-service.No adverse patient effects were reported.
Event or Problem Description
It was reported that this right ventricular (rv) lead has exhibited gradually increasing shock impedance measurements, with the most recent value being out-of-range (140 ohms).Boston scientific technical services (ts) was contacted and discussed that this lead impedance had been stable until 2020, where it began gradually increasing.As the shock impedance had not exceeded 150 ohms, ts recommended continuing with monitoring with all shocks programmed to the maximum energy (41 j), if clinically appropriate.At this time, the rv lead remains implanted and in-service.No adverse patient effects were reported.
Additional Manufacturer Narrative
This report is being sent to provide new information in section b5 (event description).
Event or Problem Description
It was reported that this right ventricular (rv) lead has exhibited gradually increasing shock impedance measurements, with the most recent value being out-of-range (140 ohms).Boston scientific technical services (ts) was contacted and discussed that this lead impedance had been stable until 2020, where it began gradually increasing.As the shock impedance had not exceeded 150 ohms, ts recommended continuing with monitoring with all shocks programmed to the maximum energy (41 j), if clinically appropriate.At this time, the rv lead remains implanted and in-service.No adverse patient effects were reported.
Additional Manufacturer Narrative
This report is being sent to provide new information in section b5 (event description).This report is being sent to provide new information in sections h6 (evaluation conclusion codes) and h11 (additional mfr narrative).This product has not been returned to boston scientific and physical analysis could not be conducted.Investigation of the available information/data determined that the observed gradual rise in lvsi measurements was likely associated with calcification, as there was no conclusive evidence of compromised physical or electrical integrity of the lead.This condition may develop over time and can be reflected in a gradual and sustained increase in shock impedance measurements.Boston scientific issued a field safety notice to physicians in july 2025 regarding the potential for reliance defibrillation leads with expanded polytetrafluoroethylene (eptfe) coating to exhibit a pattern of gradually increasing lvsi measurements due to calcification, which may result in elevated high voltage shock impedance (hvsi) measurements and reduced shock efficacy.

• Brand Name: ENDOTAK RELIANCE SG
• Common Device Name: IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (NON-CRT)
• Manufacturer (Section D): BOSTON SCIENTIFIC CORPORATION; 4100 hamline avenue north; saint paul MN 55112
• Manufacturer (Section G): BOSTON SCIENTIFIC CORPORATION; road 698, lot no. 12; dorado PR 00646 -260; * 00646-2602
• Manufacturer Contact: timothy degroot ; 4100 hamline avenue north; saint paul, MN 55112 ; 6515826168
• MDR Report Key: 23176314
• Report Number: 2124215-2025-68800
• Device Sequence Number: 9639149
• Product Code: LWS
• UDI-Device Identifier: 00802526531156
• UDI-Public: (01)00802526531156(17)150826
• Combination Product (Y/N): Y
• Initial Reporter Country: FR
• PMA/510(K) Number: P910073
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2013
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Other,Foreign,Company Representative
• Initial Reporter Occupation: Non-Healthcare Professional
• Remedial Action: Recall,Notification
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 12/11/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Lay User/Patient
• Device Expiration Date: 08/26/2015
• Device Model Number: 0181
• Device Catalogue Number: 0181
• Device Lot Number: 323671
• Was Device Available for Evaluation?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 09/16/2025
• Supplement Date Received by Manufacturer: 10/08/2025; 12/09/2025
• Initial Report FDA Received Date: 09/29/2025
• Supplement Report FDA Received Date: 11/07/2025; 12/11/2025
• Date Device Manufactured: 08/26/2013
• Is the Device Labeled for Single Use? (Y/N): Yes
• Usage of Device: Initial
• Patient Sequence Number: 1
• Patient Age: 63 YR
• Patient Sex: Male