AceShowbiz - Ashton Kutcher was so desperate to save his twin brother's life during a teenage health crisis, the actor offered to donate his own heart.

Michael Kutcher, who has congenital disorder cerebral palsy, was just 13 when he was diagnosed with the heart disease viral cardiomyopathy, and he was initially given up to a month to live, before that life expectancy was slashed to just 48 hours if doctors failed to locate a suitable donor.

Now 40, Michael reveals Ashton was devastated at the thought of losing his fraternal twin, and was willing to sacrifice himself to save his sick brother.

Luckily, that wasn't necessary as Michael received a last-minute heart transplant, which allowed him to make a full recovery, but just the thought of the That '70s Show star's generosity still makes his brother emotional.

"It's just... I can't find the words," he told Us Weekly about the touching offer. "It's a connection that you can't explain. In all seriousness, we're just very connected... It's an honour or deep appreciation and a deep love for someone who would sacrifice that for you. I really can't put words to it."

Michael, who is now living in Colorado with his 14-year-old son and his new girlfriend and her two kids, marked the 27th anniversary of his heart transplant last month, December 2018, and with his health better than ever, he is now using his own experience to encourage more people to register as organ donors as part of the #BeTheGift campaign.

"I'm thankful for the last year, to be able to touch the individuals I have, to join the #BeTheGift campaign, and get the awareness out, (to get) more donations, and to raise my son to be the amazing individual he is," Michael said.

"I have recently built a new family here in Colorado and found an amazing woman with two younger children herself. It's another chapter in my life. I'm thankful to have started writing that chapter."