MAUDE Adverse Event Report: BOSTON SCIENTIFIC CORPORATION WATCHMAN FLX? Pro; system, appendage closure, left atrial

Model Number	M635WU60310
Medical Device Problem Code	Adverse Event Without Identified Device or Use Problem (2993)
Health Effect - Clinical Codes	Bradycardia (1751); Cardiac Arrest (1762); Low Blood Pressure/ Hypotension (1914); Tachycardia (2095); Ventricular Fibrillation (2130)
Date of Event	08/15/2026
Type of Reportable Event	Death
Event or Problem Description
It was reported hypotension, bradycardia, cardiac arrest and death occurred.A concomitant procedure (ablation/left atrial appendage closure (laac)) was being performed.A watchman trusteer access system (was) and a 31mm watchman flx pro laa closure device and delivery system (wds) was selected for use.After the ablation portion of the procedure, the laac procedure was completed without any reported complications.Electrocardiogram (ekg) monitoring showed no st-segment elevation or evidence of any lethal arrhythmias.At the conclusion of the procedure, the physician was in the process of closing the groin access site, and protamine was administered to reverse the effects of heparin anticoagulation.The anesthesia physician observed a sudden decline in the patient's blood pressure along with bradycardia.Cardiopulmonary resuscitation (cpr) was initiated.A transesophageal echocardiogram (tee) was performed to evaluate for a potential pericardial effusion or cardiac tamponade as a cause of the hemodynamic instability.No pericardial effusion was identified on tee.Despite resuscitative efforts, the patient remained unstable and experienced recurrent episodes of ventricular tachycardia (vt) and ventricular fibrillation (vf).Multiple defibrillation attempts were performed; however, the patient continued to degenerate into vt and vf.Due to the persistent ventricular arrhythmias and ongoing hemodynamic compromise, extracorporeal membrane oxygenation (ecmo) support was initiated.Even after ecmo cannulation, the patient continued to require cpr and repeated defibrillation because of recurrent vt/vf episodes.Given the continued instability, the patient was transported from the procedure room for computed tomography angiography (cta) evaluation, with possible impella placement being considered following imaging.The physician suspected the heart rate, and pressure issues were related to an unexpected reaction to protamine.The patient was reported to have passed away the next day while in the intensive care unit (icu).
Additional Manufacturer Narrative
With all the available information, boston scientific (bsc) concludes: device technical analysis: the watchman flx? pro remains implanted; therefore, returned device analysis could not be completed.Device history record review: a review was completed of the device history records (dhr) for the watchman flx? pro, part # m635wu60310 batch # 0039095633.The dhr review confirmed that the device met all material, assembly, and performance specifications prior to distribution.Labeling review: there was no evidence to suggest that the device was used in a manner inconsistent with the labeling.Watchman flx? pro instructions for use (ifu) lists potential complications, risks and adverse events that may be associated with the use of this device which include arrhythmia (ventricular fibrillation, ventricular tachycardia, bradycardia, cardiac arrest), hypotension, and death.Risk review: a risk review was completed and confirmed that the events of arrhythmia (ventricular fibrillation, ventricular tachycardia, bradycardia, cardiac arrest), hypotension, and death were defined in the risk documentation.These event types have been accounted for during product risk analysis to support acceptable risk benefit for the product.Investigation conclusion: based on a thorough review of the reported complaint, boston scientific has assigned an investigation conclusion code of no problem detected.
Event or Problem Description
It was reported hypotension, bradycardia, cardiac arrest and death occurred.A concomitant procedure (ablation/left atrial appendage closure (laac)) was being performed.A watchman trusteer access system (was) and a 31mm watchman flx pro laa closure device and delivery system (wds) was selected for use.After the ablation portion of the procedure, the laac procedure was completed without any reported complications.Electrocardiogram (ekg) monitoring showed no st-segment elevation or evidence of any lethal arrhythmias.At the conclusion of the procedure, the physician was in the process of closing the groin access site, and protamine was administered to reverse the effects of heparin anticoagulation.The anesthesia physician observed a sudden decline in the patient's blood pressure along with bradycardia.Cardiopulmonary resuscitation (cpr) was initiated.A transesophageal echocardiogram (tee) was performed to evaluate for a potential pericardial effusion or cardiac tamponade as a cause of the hemodynamic instability.No pericardial effusion was identified on tee.Despite resuscitative efforts, the patient remained unstable and experienced recurrent episodes of ventricular tachycardia (vt) and ventricular fibrillation (vf).Multiple defibrillation attempts were performed; however, the patient continued to degenerate into vt and vf.Due to the persistent ventricular arrhythmias and ongoing hemodynamic compromise, extracorporeal membrane oxygenation (ecmo) support was initiated.Even after ecmo cannulation, the patient continued to require cpr and repeated defibrillation because of recurrent vt/vf episodes.Given the continued instability, the patient was transported from the procedure room for computed tomography angiography (cta) evaluation, with possible impella placement being considered following imaging.The physician suspected the heart rate, and pressure issues were related to an unexpected reaction to protamine.The patient was reported to have passed away the next day while in the intensive care unit (icu).

• Brand Name: WATCHMAN FLX? Pro
• Common Device Name: system, appendage closure, left atrial
• Manufacturer (Section D): BOSTON SCIENTIFIC CORPORATION; 300 boston scientific way; marlborough MA 01752
• Manufacturer (Section G): Boston Scientific Corporation; ballybrit business park; galway H91 Y 868; EI H91 Y868
• Manufacturer Contact: mary crawford ; 4100 hamline ave n; arden hills, MN 55112 ; +1(651)440-0979
• MDR Report Key: 50378996
• Report Number: 2124215-2026-45208
• Device Sequence Number: 5663133
• Product Code: NGV
• UDI-Device Identifier: 00191506004613
• UDI-Public: (01)00191506004613(17)290414(10)39095633
• Combination Product (Y/N): N
• Initial Reporter State: NJ
• Initial Reporter Country: US
• PMA/510(K) Number: P130013
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2026
• Reporter Type: Manufacturer
• Report Source: Health Professional,Company Representative
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 09/24/2026

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?: No
• Operator of Device: Health Professional
• Device Model Number: M635WU60310
• Device Catalogue Number: M635WU60310
• Device Lot Number: 0039095633
• 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: Not provided
• Supplement Date Received by Manufacturer: 09/23/2026
• Initial Report FDA Received Date: 08/21/2026
• Supplement Report FDA Received Date: 09/24/2026
• Date Device Manufactured: 04/15/2026
• 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: Required Intervention; Other; Death
• Patient Age: 81 YR
• Patient Sex: Male