Former Vice President Dick Cheney, whose lifelong fight with heart disease hobbled his movements before his 2012 transplant, has fully recovered and is back on the speaking and social circuit with a robustness friends haven't seen since he was in the White House.

"He's in great shape, I can vouch for him," said former Defense Secretary Donald Rumsfeld. "Take a look at him," he added as the two stood side-by-side at a Georgetown book party for the release of "Rumsfeld's Rules."

Cheney, who is co-authoring a book on heart disease with one of his doctors, is opening up more about his battle dating back to 1978 when he suffered the first of six heart attacks.

This week the 72-year-old former Pentagon chief flew to Minneapolis where he told the American Association for Thoracic Surgery 2013 Annual Meeting about the difficulty dealing with the hospital visits and the thrill of finally getting a transplant.

"When I came out of sedation, and the surgeon told me the operation was a success, my response to that was 'hot damn!' It all becomes real at that moment, and you're free to wake up every day with a smile on your face, feeling grateful for every moment you have," he said, according to the group's write-up about the speech.

Cheney, who said that he has compared heart attack notes with former President Bill Clinton, added that he has never worried about the next attack. "It wasn't like I was sitting there on 9/11 wondering, 'Gee, is this going to hurt my heart condition?' You keep it separate from your career," he said. "I never felt that I was in place where I couldn't do something because of my health issues...I've led a very full and active life."

At his book party, Rumsfeld said that some people are concerned about Cheney's health. He recalled getting in a cab recently and the Kenyan driver asked about about Rumsfeld's friend. "How's Cheney?" asked the driver. "This guy was from Kenya and I couldn't believe it. I said, 'How about me?'" said Rumsfeld. "Good man," the driver said of Cheney, added Rumsfeld.