Heart valve disease, which occurs when the heart valves do not work the way they should, represents a diffused cause of death (according to the American Heart Association, about 5 million Americans are diagnosed with heart valve disease each year). There are several types of heart valve disease and the treatment depends on the type of disease and how severe it is, as well as on the overall health status of the patient, the age and weight. In most of the cases, valve replacement with prosthetic devices is required. The new generations of prosthetic heart valves are fabricated using biological tissues for valve leaflets, in particular pericardial tissue.