Mechanical Valve & Coumadin

What is A Mechanical Heart Valve?

A mechanical heart valve is made from materials that do not include any form of biological tissue (pig, cow, horse). Instead, very strong materials -- such as titanium and carbon -- are used in a mechanical heart valve that make them incredibly strong and durable. Some reports suggest that the mechanical valves available today are able to last indefinitely. Recently, an accelerated wear tester suggested that one mechanical heart valve could last over 50,000 years.

However, a key consideration for patients is that mechanical valves require continuous use of blood thinners, also known as anticoagulants, such as Coumadin. Patients on Coumadin therapy need to be monitored regularly with a PT (Prothrombin) blood test. These blood tests help ensure that the patient’s INR (International normalised ratio) is acceptable. For example if the INR level is 5, this indicates an elevated chance of bleeding, whereas an INR level of .5 indicates the possibility of a blood clot. *I personally have to keep my INR between 2.0-3.5*
The three major kinds of mechanical heart valve replacements are the tilting-disc mechanical valve, the bileaflet mechanical valve, and the original caged-ball mechanical valve.

The ‘Bileaflet’ Mechanical Valve

A bileaflet mechanical valve consists of two leaflets that are semicircular and rotate around struts that are attached to the housing of the valve. In 1979, the bileaflet valve design was introduced. Some reports suggest that bileaflet mechanical valves povide more natural bloodflow compared to the aforementioned mechanical heart valves.

Advantages Of Mechanical Heart Valves

The main advantage of mechanical heart valve replacements is durability.

• Mechanical heart valves are made from very durable materials including titanium, carbon compounds and teflon. While the average tissue valve (porcine, bovine, equine) is estimated to last between 10-15 years, reports suggest that mechanical valves can last 30 years or more after implant. That said, for some younger patients, a mechanical heart valve can be a suitable replacement for the diseased valve.

Disadvantages of Mechanical Heart Valves

There are a few disadvantages, or considerations, that should be noted about mechanical heart valves.

• First, to reduce the risk of clotting, patients are required to use blood thinners (e.g. Coumadin, Warfarin) for the balance of their lives.
• Second, due to the mechanical nature of the valve, some patients can hear their valves "click" while opening-and-closing in their hearts.
• Third, with the ongoing interest and use of transcatheter valve replacements, it is not possible to replace a mechanical valve should complications occur years after implant.

Selecting a heart valve replacement is a very important decision for the patient, their family and friends.