After months of refusing to release mortality rates for its troubled pediatric cardiothoracic surgery program, the University of Kentucky reversed course Friday and issued a statement disclosing the numbers. UK Healthcare CEO Michael Karpf said the program had an overall mortality rate of 5.8 percent from 2008 to 2012. During that period, annual mortality rates ranged from 4.5 percent to 7.1 percent, Karpf said in a statement. "These ranges are comparable to national mortality rates averaging 5.3 percent for programs of similar size to ours," Karpf said. More than 500 people have signed an online petition in the last week urging UK to release information about how many children died after undergoing heart surgery at Kentucky Children's Hospital. Read more.