MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION ACUITY? X4 Spiral L; Implantable lead

Model Number	4677
Medical Device Problem Codes	Failure to Capture (1081); Over-Sensing (1438); Pacing Problem (1439); Failure to Read Input Signal (1581)
Health Effect - Clinical Codes	Bradycardia (1751); Low Blood Pressure/ Hypotension (1914); Tachycardia (2095); Ventricular Fibrillation (2130)
Date of Event	05/09/2026
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
This product investigation is still in progress.This report will be updated when product investigation is complete.If pertinent information is provided in the future, a supplemental report will be submitted.
Event or Problem Description
It was reported that the patient with this cardiac resynchronization therapy defibrillator (crt-d) system including this right atrial (ra) lead, right ventricular (rv) lead and left ventricular (lv) lead was programmed to lv pacing only, following a prior ventricular fibrillation (vf) storm and hospitalization on life support, with subsequent observations of atrial activity tracking and rv pacing associated with decreased blood pressure.Programming adjustments were performed to prevent fusion, and it was noted that lv pacing morphology appeared narrower compared to rv pacing.Technical services (ts) reviewed the available data and noted that fusion patterns were likely related to lv pacing given the current programming settings and that the left ventricular protection period (lvpp) feature inhibit lv pacing and result in rv pacing delivery.Further evaluation included temporary atrial pacing, during which no farfield oversensing was observed on the lv channel.Review of the presenting electrogram (egm) indicated that r-wave deflections on rv and lv channels appeared aligned rather than lv first.Ts provided reprogramming recommendations, and the field representative confirmed lead positioning via chest imaging.It was further reported on a subsequent review that during right atrial automatic threshold (raat) testing, loss of right atrial (ra) capture appeared to be associated with a slow ventricular tachycardia (vt) rhythm.Ts reviewed the presenting egm and noted that during lv pacing, findings suggested lv loss of capture (loc), as the qrs complex on the shock egm appeared significantly delayed following pacing.During left ventricular automatic threshold (lvat) testing, double deflection on the lv channel was observed, suggestive of potential latency.Additional programming changes did not result in improvement.It was also discussed that multiple rv sensed markers observed on the presenting egm may be attributable to device algorithms or annotations.It was noted that the patient is currently intubated, and ts discussed that the observed behaviors may be related to the patient's overall clinical status, with no additional programming changes expected to resolve the condition at this time.This lv lead remains in service and no additional adverse patient effects were reported.
Event or Problem Description
It was reported that the patient with this cardiac resynchronization therapy defibrillator (crt-d) system including this right atrial (ra) lead, right ventricular (rv) lead and left ventricular (lv) lead was programmed to lv pacing only, following a prior ventricular fibrillation (vf) storm and hospitalization on life support, with subsequent observations of atrial activity tracking and rv pacing associated with decreased blood pressure.Programming adjustments were performed to prevent fusion, and it was noted that lv pacing morphology appeared narrower compared to rv pacing.Technical services (ts) reviewed the available data and noted that fusion patterns were likely related to lv pacing given the current programming settings and that the left ventricular protection period (lvpp) feature inhibit lv pacing and result in rv pacing delivery.Further evaluation included temporary atrial pacing, during which no farfield oversensing was observed on the lv channel.Review of the presenting electrogram (egm) indicated that r-wave deflections on rv and lv channels appeared aligned rather than lv first.Ts provided reprogramming recommendations, and the field representative confirmed lead positioning via chest imaging.It was further reported on a subsequent review that during right atrial automatic threshold (raat) testing, loss of right atrial (ra) capture appeared to be associated with a slow ventricular tachycardia (vt) rhythm.Ts reviewed the presenting egm and noted that during lv pacing, findings suggested lv loss of capture (loc), as the qrs complex on the shock egm appeared significantly delayed following pacing.During left ventricular automatic threshold (lvat) testing, double deflection on the lv channel was observed, suggestive of potential latency.Additional programming changes did not result in improvement.It was also discussed that multiple rv sensed markers observed on the presenting egm may be attributable to device algorithms or annotations.It was noted that the patient is currently intubated, and ts discussed that the observed behaviors may be related to the patient's overall clinical status, with no additional programming changes expected to resolve the condition at this time.This lv lead remains in service and no additional adverse patient effects were reported.
Additional Manufacturer Narrative
This product remains implanted and in-service.As such, physical analysis has not been conducted in our laboratory.Based on the available information, and in the absence of a product return, boston scientific has assigned an investigation conclusion code of no problem detected.A review of the device history record (dhr) was performed.The review of the dhr identified that there were no process related non-conformances, scrap, or rework performed during the production that could explain the event.The reviews ensure each device meets specification prior to release for use.There is no indication the device manufacturing process contributed to the reported complaint.Review of labeling determined that the complaint situation was listed in the manual.There was no indication in the complaint that the product was not used in accordance to labeling.The manual was unlikely to be the cause of the reported complaint; translation, wording, or graphics does not require further review.This product investigation is still in progress.This report will be updated when product investigation is complete.If pertinent information is provided in the future, a supplemental report will be submitted.

• Brand Name: ACUITY? X4 Spiral L
• 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; PR 00646-2602
• Manufacturer Contact: mark mischke ; 4100 hamline avenue north; saint paul, MN 55112 ; +1(612)875-7234
• MDR Report Key: 25444828
• Report Number: 2124215-2026-30678
• Device Sequence Number: 5763866
• Product Code: LWP
• UDI-Device Identifier: 00802526524592
• UDI-Public: (01)00802526524592(17)250620
• Combination Product (Y/N): Y
• Initial Reporter State: MA
• Initial Reporter Country: US
• PMA/510(K) Number: P010012
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2024
• Reporter Type: Manufacturer
• Report Source: Company Representative
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial,Followup
• Report Date (Section B): 09/09/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Operator of Device: Lay User/Patient
• Device Expiration Date: 06/20/2025
• Device Model Number: 4677
• Device Catalogue Number: 4677
• Device Lot Number: 835292
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Was the Report Sent to FDA?: No
• Type of Report(Section G): Thirty-Day
• Initial Date Received by Manufacturer: 05/11/2026
• Supplement Date Received by Manufacturer: 08/20/2026
• Initial Report FDA Received Date: 06/09/2026
• Supplement Report FDA Received Date: 09/09/2026
• Was Device Evaluated by Manufacturer? (Y/N): No
• Date Device Manufactured: 06/21/2023
• 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
• Outcome Attributed to Adverse Event: Other; Hospitalization; Life Threatening
• Patient Age: 59 YR
• Patient Sex: Male