Anne Bunting liked to tell friends that President Barack Obama saved her life.

Last month, the Houston native decided to pen a letter telling him so, explaining how his signature health care law had allowed her to get a life-saving heart transplant in 2014.

"I tell everyone that you saved my life and I truly believe that," she wrote.

That, she thought, would be that.

Then last Friday she got a reply: "Thank you for your kind words and for taking the time to share your moving story with me. It's clear you have faced tremendous challenges over the last few years, and I am glad to hear the Affordable Care Act helped you."

It was signed with the president's characteristic signature, with a giant B and a giant O.