Following her son Prince Alexandre's heart surgery in Boston, Massachusetts in 1957, Princess Lilian became very interested in medicine, and, in particular, in cardiology, and founded a Cardiological Foundation in 1958 to promote new forms of treatment for cardiovascular diseases, which, through its work, has saved the lives of hundreds of people. Both before and after her husband's death in 1983, Lilian pursued her interests in intellectual and scientific spheres with energy and passion.Michel Verwilghen, Princess Lilian also personally financed a number of Belgian children who needed to go to the United States for operations. Princess Lilian and her husband appeared in public at a ceremony for the Brussels Exhibition of 1958. In 1961, Lilian inaugurated a new cardiac research laboratory at the Hospital Saint-Pierre in Brussels.
