Vladimir Lenin
A woman named Fanny Kaplan shot Lenin whilst he was making an official visit.  She missed his head and instead the bullet was lodged into his neck.  Fearing that he would be killed by political dissenters, he refused to have the bullet removed until a guaranteed Communist doctor could be found. As a result of his direct refusal to be treated, the bullet was never removed, and is often cited as the reason he started having strokes in May and December 1922 (both of which he recovered from). In March 1923 a stroke paralyzed him and left him unable to speak, and he died on January 24, 1924 of a stroke. Just before he died, Lenin had wanted to get rid of Stalin because he thought he was dangerous to the country and the government.