MAUDE Adverse Event Report: ON-X LIFE TECHNOLOGIES, INC. ON-X PROSTHETIC MITRAL VALVE WITH STANDARD SEWING RING; HEART-VALVE, MECHANICAL

Model Number ONXM-25

Device Problems Adverse Event Without Identified Device or Use Problem (2993); Insufficient Information (3190)

Patient Problems Apnea (1720); Chest Pain (1776); Fatigue (1849); Regurgitation (2259)

Event Date 05/04/2018

Event Type  Injury  

Manufacturer Narrative

This investigation is currently ongoing.Any additional information will be provided in the follow-up report.

Event Description

According to initial reports, tee from (b)(6) 2018 states "the ejection fraction is 55-60%.The left atrium is moderately dilated.There is no evidence of aortic stenosis.Subaortic stenosis present with a peak of 62 mm hg.Secondary to the post of the mechanical mitral valve impinging flow in the lvot." surgeon consult on (b)(6) 2018 states "in (b)(6) 2015 [(b)(6) 2015], i performed mitral valve replacement for rheumatic disease and mitral stenosis.[patient] has done well with her on-x mechanical mitral valve.Recently echocardiography revealed full acceleration in the outflow tract consistent with left ventricular outflow tract obstruction.On a transthoracic study, the mean gradient was 18 mmhg with a peak of 36 at rest and increased to only 46 and 19 with valsalva.The mechanical mitral valve is functioning nonnally with a gradient of 5 mmhg and no valvular or paravalvular insufficiency.There is mild tricuspid aortic regurgitation.The aortic valve appears normal.A repeat transthoracic study a month later found the mean outflow gradient to be a bit higher in the low 30s.Of note, on echocardiography in (b)(6) 2016, she achieved 7 mets with a mean gradient of 4 mmhg across the valve.With respect to symptoms, [patient] tells me that she finds herself fatigued during the day.She is not having any exertional shortness of breath or chest pain.She denies palpitations.".

Manufacturer Narrative

Correction - please note the patient did not experience chest pain.The manufacturing records for the onxmc-25, sn (b)(4) were reviewed and it was confirmed that all records were controlled, available for review, and met all specifications per the device master record.All lots passed functional testing and met release specifications.During the investigation no non-conformances or deviations were noted.Medical records were reviewed.According to the records, the echocardiography revealed full acceleration in the outflow tract consistent with left ventricular outflow tract obstruction.On a transthoracic study, the mean gradient was 18 mmhg with a peak of 36 at rest and increased to only 46 and 19 with valsalva.The mechanical mitral valve is functioning normally with a gradient of 5 mmhg and no valvular or paravalvular insufficiency.There is mild tricuspid aortic regurgitation.The aortic valve appears normal.A repeat transthoracic study a month later found the mean outflow gradient to be a bit higher in the low 30s.Of note, on echocardiography in march of 2016, she achieved 7 m ets with a mean gradient of 4 mm hg across the valve.Patient is fatigued during the day.Patient is not experiencing exertional shortness of breath or chest pain.Patient has a history of obstructive sleep apnea and does not wear cpap mask.There are no reported neurologic symptoms.She has no numbness or radicular discomfort.The patient is not having any visual disturbance or hearing loss.She feels generally fatigued during the day.She is not short of breath, having chest pain or palpitations.According to the review of these records, a transesophageal echo three years after implant, revealed a subaortic stenosis with a peak gradient of 62mmhg.With the exception of some fatigue during the day, which may be related to sleep apnea, the patient is otherwise asymptomatic.The report of consultation speculates on potential causes of the subaortic stenosis.The most likely candidate is some form of obstruction in the left ventricular outflow tract (lvot).It is possible that the valve is seated lower than is typical and that the shape of the valve outflow may contribute to the flow obstruction, but the surgeon notes that the patient had considerable manipulation of the chordae tendineae upon implantation and that the ventricle was itself rather small to begin with ("compact ventricle").Septal hypertrophy may also be a contributing factor.The echo reports a normally functioning mechanical prosthesis.In summary, there seems to be ari obstruction of the lvot, but the cause, or more likely, causes, are not definitive.For now, because of the lack of adverse symptoms, the patient will not have an intervention, but remain under observation.The information available suggests the valve is functioning normally, but that anatomic factors, which may be exacerbated by the position and/or shape of the valve, contribute to a noticeably high lvot gradient, indicative of flow obstruction.It is possible this may be classified as a prosthesis nonstructural dysfunction [instructions for use], but the root cause of the obstruction remains unknown.Therefore it is still uncertain what, if any, contribution the valve has to the diagnosis of lvot obstruction.This report is being submitted as required by federal regulations and does not constitute an admission that the device caused or contributed to the reported event.Furthermore, this report reflects the event as alleged by the complainant and does not imply that the information reported to cryolife is accurate or has been confirmed by cryolife.

Event Description

According to initial reports, tee from (b)(6)2018 states "the ejection fraction is 55-60%.The left atrium is moderately dilated.There is no evidence of aortic stenosis.Subaortic stenosis present with a peak of 62 mm hg.Secondary to the post of the mechanical mitral valve impinging flow in the lvot." surgeon consult on (b)(6)2018 states "in april of 2015(b)(6)2015 , i performed mitral valve replacement for rheumatic disease and mitral stenosis.[patient] has done well with her on-x mechanical mitral valve.Recently echocardiography revealed full acceleration in the outflow tract consistent with left ventricular outflow tract obstruction.On a transthoracic study, the mean gradient was 18 mmhg with a peak of 36 at rest and increased to only 46 and 19 with valsalva.The mechanical mitral valve is functioning nonnally with a gradient of 5 mmhg and no valvular or paravalvular insufficiency.There is mild tricuspid aortic regurgitation.The aortic valve appears normal.A repeat transthoracic study a month later found the mean outflow gradient to be a bit higher in the low 30s.Of note, on echocardiography in march of 2016, she achieved 7 mets with a mean gradient of 4 mmhg across the valve.With respect to symptoms, [patient] tells me that she finds herself fatigued during the day.She is not having any exertional shortness of breath or chest pain.She denies palpitations.".

• Brand Name: ON-X PROSTHETIC MITRAL VALVE WITH STANDARD SEWING RING
• Type of Device: HEART-VALVE, MECHANICAL
• Manufacturer (Section D): ON-X LIFE TECHNOLOGIES, INC.; 1300 e. anderson ln., bldg. b; austin TX 78752
• MDR Report Key: 7604636
• MDR Text Key: 111147015
• Report Number: 1649833-2018-00113
• Device Sequence Number: 1
• Product Code: LWQ
• Combination Product (y/n): N
• PMA/PMN Number: P000037
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,health
• Type of Report: Initial,Followup
• Report Date: 09/26/2018

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 06/15/2018
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Physician
• Device Model Number: ONXM-25
• Was Device Available for Evaluation?: No
• Distributor Facility Aware Date: 06/12/2018
• Date Manufacturer Received: 06/12/2018
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Other
• Patient Age: 58 YR