It's purely anecdotal but does have some provenance going back at least to the 19th century, with one of the early liver specialists.

He was reportedly at a cocktail party one evening when a messenger burst in and informed the esteemed doctor that one of his patients appeared to be dying from a heart attack.

"My good man," he replied, "that can't possibly be true. When I treat a patient for liver disease he dies of liver disease."