prosthetic heart valve

When a valve is too damaged to repair, surgeons can swap it out for an artificial one — a prosthetic heart valve that takes over the job of opening and closing in one direction. There are two broad families, each with a clear trade-off.

Mechanical valves are made of durable materials such as carbon and metal and can last a lifetime, but blood tends to clot on their surfaces, so recipients must take a blood-thinning anticoagulant (such as warfarin) indefinitely, with regular monitoring. Bioprosthetic (tissue) valves are fashioned from animal tissue, usually need no long-term anticoagulation, but wear out over time and may require re-replacement, which is why they are often chosen for older patients.

Valves can be implanted by open-heart surgery or, increasingly, by catheter without opening the chest — for example transcatheter aortic valve replacement. Whatever the type, prosthetic valves carry lifelong considerations: a small ongoing risk of clot formation, of infection of the valve (prosthetic endocarditis), and eventual structural failure. People with prosthetic valves are followed regularly and given antibiotic precautions for certain procedures.

Choosing valve type and anticoagulation strategy is highly individualized, weighing age, bleeding risk, and patient preference; this entry only outlines the options.