Mark Dedomenico, an influential heart surgeon and longtime Thoroughbred owner who was a member of the partnership that raced the legendary filly Blind Luck, died on Saturday in Washington state. Dedomenico was 87. His death was announced by Emerald Downs officials on Sunday. As a horse owner, Dedomenico raced frequently in the Pacific Northwest and California. He owned the Pegasus training center in Redmond, Wash., which opened in 2005 and is held in high regard throughout the West Coast. Dedomenico co-owned Blind Luck, the champion 3-year-old filly of 2010. Acquired privately after she won her debut as a 2-year-old at Calder in 2009, Blind Luck later won 10 stakes, including three Grade 1 races in 2010 – the Las Virgenes Stakes at Santa Anita, the Kentucky Oaks at Churchill Downs, and the Alabama Stakes at Saratoga. Co-owned by John Carver, Peter Abruzzo and trainer Jerry Hollendorfer, Blind Luck raced until the fall of 2011. She ended her career with 12 wins in 22 starts and earnings of $3,279,520. “That was the highlight of doing business with Mark,” Hollendorfer said. Dedomenico later paid $2.5 million for Blind Luck at the 2011 Keeneland November Breeding Stock Sale, buying out the partners. In partnership with Hollendorfer and George Todaro, Dedomenico co-owned Sam’s Sister, the winner of the Grade 1 La Brea Stakes for 3-year-old fillies at Santa Anita in 2014. In a different partnership, Dedomenico raced She’s a Tiger, who finished first in the Breeders’ Cup Juvenile Fillies at Santa Anita in 2011, but was disqualified and placed second for causing interference in the stretch. She’s a Tiger, trained by Jeff Bonde, won the Grade 1 Del Mar Debutante earlier that year. In an interview between races at Los Alamitos on Sunday, Hollendorfer described Dedomenico as “irreplaceable.” “We were friends and partners,” Hollendorfer said. “The man helped a lot of people – on and off the track. “He was a very intelligent man and a generous man." Hollendorfer said training for Dedomenico came with expectations. “He was a little bit tough,” Hollendorfer said. “He wanted results in everything he did.” Other prominent runners co-owned by Dedomenico included Bwana Bull, who won the El Camino Real Derby at Bay Meadows in 2007 and was 15th that year behind Street Sense in the Kentucky Derby; and Prime Engine, who won the 2014 Joe Gottstein Futurity and 2015 Emerald Downs Derby. Dedomenico, who lived in Redmond, Wash., served as a medic in Vietnam. He later worked with other surgeons to develop coronary bypass surgery, according to the American Heart Association. A former member of the board of directors of the Thoroughbred Owners of California and the Washington Thoroughbred Owners and Breeders’ Association, Dedomenico was a founding member of Seattle’s Hope Heart Institute. Dedomenico had a racing background, courtesy of his father Paskey, who owned horses in the 1970s and 1980s. The family owned Golden Grain Macaroni, Co., which produced Rice-a-Roni, and later acquired Ghiradelli Chocolate Co. The companies were sold to Quaker Oaks in the 1980s. Mark Dedomenico worked as an executive with Golden Grain. Through his professional career, Dedomenico was actively involved in wellness programs devoted to preventative care to reduce the risks of obesity, cholesterol and high blood pressure.