Silzone valves linked to Stroke and Adverse Side Effects

The St. Jude Silzone valve has now been withdrawn from the market but not before 36,000 Silzone coated heart valves had been implanted in patients throughout the world.

Silver coating of the sewing ring (Silzone) was introduced as a modification of the St Jude Medical standard valve to provide antibacterial protection.

The recall followed reports of unacceptable levels of product re-operations to remove and repair silzone valves due to paravalvular leaks. A paravalvular leak is a flow of blood around the artificial valve usually between the valve sewing ring and the heart tissue to which the valve is attached.

To determine adverse affects in patients with Silzone mechanical heart valves manufactured by St. Jude Medical Inc., a [study] was first conducted by the Department of Cardiothoracic Surgery, University Hospital of Wales.

It confirmed that patients with Silzone mitral valves had a high rate of early postoperative embolism compared to standard St. Jude mechanical heart valves.

There may also be a concern that persons implanted with Silzone valves face higher risks of thrombus formation, thrombosis and stroke.

A thrombus is a blood clot that can form upon the valve, affecting its operation or even rendering it inoperable. Thrombosis is a condition in which blood clots form and then move through the blood stream. These clots can ultimately cause a transient ischemic attack (TIA) or a stroke due to thromboembolism.

Data was later presented at the American Heart Association in Atlanta, which determined that persons implanted with the silzone valves had much higher incidences of stroke and major embolism. The increase in incidence was greatest among patients implanted with either a mitral silzone valve or both a mitral and aortic silzone valve.

A voluntary [recall] from St. Jude Medical was issued in January 2000. It no longer distributes any devices with Silzone coating.

Persons with medical questions concerning this information should talk to their cardiologist or other doctor.

Contact: St. Jude Medical Toll Free: 800.922.9219 or Phone #: 651.490.4305