His heart problems first became public in 2017, when he struggled through a play

Stacy Keach died on Tuesday at his family home in Magdalenka, Poland, his wife Malgosia Keach said in a statement to People. He had lived with a serious heart condition for years and died of heart failure. She described him as a legendary actor loved by audiences worldwide, and also as her husband, her companion and the heart of their family.
The statement read, "It is with profound sadness and a broken heart that I announce the passing of my darling husband, Stacy Keach. After a long and difficult battle with a serious heart condition and heart failure, Stacy peacefully departed this world. He fought for so long, with extraordinary courage, determination and strength."
A detective he had waited a lifetime to play
Most television viewers will remember him for the trench coat. Keach first played Mickey Spillane’s private eye in the 1983 CBS television movie Murder Me, Murder You. That led to The New Mike Hammer in 1984, and he returned to the character in later TV films and in the 1997 series Mike Hammer, Private Eye.
The role meant a great deal to him. In his 2013 memoir, All in All: An Actor’s Life On and Off the Stage, Keach said Spillane’s novels had captivated him as a boy, and that playing Hammer was a dream he carried for decades before it came true.
The boxer who made his name
His reputation in film was established more than ten years earlier. In John Huston’s Fat City (1972), Keach played Billy Tully, a fading boxer stuck in the small-time circuit of Stockton, California. The performance is still regarded as one of the defining portrayals in 1970s American cinema.
That same year, he made The Life and Times of Judge Roy Bean with Huston again and starred with George C. Scott in the police drama The New Centurions. His screen credits also include The Heart Is a Lonely Hunter, Doc, Brewster McCloud and That Championship Season. Late in his career, younger audiences knew him from The Bourne Legacy, American History X, Prison Break, Titus and Lights Out, and from Alexander Payne’s Oscar-nominated Nebraska.
A classical actor first
Keach never became a conventional box office star, and he never seemed to need to be one. His strongest reputation was in the theatre, where his Shakespeare earned him a status few American actors of his generation reached. Clive Barnes, the influential New York Times critic, called him “one of the great Hamlets of our time” and ranked him as the best American classical actor since John Barrymore.
Prison, recovery and a second act
In 1984, the year his Hammer series began, his career was abruptly interrupted. British authorities arrested Keach at Heathrow Airport for cocaine possession, and he served six months in Reading Prison before being released early for good behavior.
He did not hide from what happened. In later years, Keach spoke openly about his addiction and said rehabilitation had allowed him to rebuild both his life and his career. He testified publicly about substance abuse and thanked First Lady Nancy Reagan for her support during his recovery.
A final curtain call
His heart problems first became public in 2017. Keach struggled through the opening night of Pamplona, a one-man play in Chicago, and doctors later found he had suffered a mild heart attack. The remaining performances were cancelled.
He returned to the role later, saying he felt he owed it to the production and to the audiences who had bought tickets.