MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION RELIANCE 4-FRONT?; IMPLANTABLE LEAD

Model Number	0663
Medical Device Problem Code	High impedance (1291)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	09/30/2025
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
If pertinent information is provided in the future, a supplemental report will be submitted.
Event or Problem Description
It was reported that this right ventricular (rv) lead exhibited an out of range gradual increase in shock lead impedance measurements.Technical services (ts) reviewed and provided troubleshooting options.This lead remains in service.No adverse patient effects were reported.
Additional Manufacturer 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.If pertinent information is provided in the future, a supplemental report will be submitted.
Event or Problem Description
It was reported that this right ventricular (rv) lead exhibited an out of range gradual increase in shock lead impedance measurements.Technical services (ts) reviewed and provided troubleshooting options.This lead remains in service.No adverse patient effects were reported.

• Brand Name: RELIANCE 4-FRONT?
• Common Device Name: IMPLANTABLE LEAD
• 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: 23376652
• Report Number: 2124215-2025-76392
• Device Sequence Number: 9202009
• Product Code: NVY
• UDI-Device Identifier: 00802526592805
• UDI-Public: (01)00802526592805(17)240526
• Combination Product (Y/N): Y
• Initial Reporter State: WA
• Initial Reporter Country: US
• PMA/510(K) Number: P910073
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2022
• Serviced by Third Party (Y/N): Unknown
• Reporter Type: Manufacturer
• Report Source: Health Professional
• Initial Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 02/27/2026

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: 05/26/2024
• Device Model Number: 0663
• Device Catalogue Number: 0663
• Device Lot Number: 173504
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 10/02/2025
• Supplement Date Received by Manufacturer: 02/27/2026
• Initial Report FDA Received Date: 10/24/2025
• Supplement Report FDA Received Date: 02/27/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 05/26/2022
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Patient Age: 75 YR
• Patient Sex: Male