Addressing the matter via Twitter on Friday, the 64-year-old comedian sent a heartfelt message to Heche's loved ones.
"This is a sad day," DeGeneres wrote. "I'm sending Anne's children, family and friends all of my love."
This is a sad day. I'm sending Anne's children, family and friends all of my love.
— Ellen DeGeneres (@TheEllenShow) August 12, 2022
Heche never regained consciousness. She was left in critical condition and intubated.
"She has a significant pulmonary injury requiring mechanical ventilation and burns that require surgical intervention," a rep for the actress told PEOPLE on Aug. 8. "She is in a coma and has not regained consciousness since shortly after the accident."
Bob Riha Jr./Getty
On Thursday, Heche's rep gave PEOPLE a bleak health update on behalf of Heche's family.
"Unfortunately, due to her accident, Anne suffered a severe anoxic brain injury and remains in a coma, in critical condition," the rep said in a statement. "She is not expected to survive."
"It has long been her choice to donate her organs and she's being kept on life support to determine if any are viable," the rep told PEOPLE.
The statement went on to express gratitude for the outpouring of support and for the care shown for Heche.
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"We want to thank everyone for their kind wishes and prayers for Anne's recovery and thank the dedicated staff and wonderful nurses that cared for Anne at the Grossman Burn Center at West Hills hospital," the statement continued.
Additionally commenting on her legacy, the rep said: "Anne had a huge heart and touched everyone she met with her generous spirit."
"More than her extraordinary talent, she saw spreading kindness and joy as her life's work — especially moving the needle for acceptance of who you love," the statement continued. "She will be remembered for her courageous honesty and dearly missed for her light."
Heche previously dated DeGeneres from 1997 to 2000. At the time, their relationship faced scrutiny because they were one of the first openly gay couples in Hollywood.
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Since their split, DeGeneres — who has been married to Portia de Rossi since 2008 — has often refrained from speaking about Heche publicly.
In an April 2003 issue of PEOPLE, DeGeneres said when asked whether she'd discuss the former relationship: "No."
"I never have and I won't," she added. "At some point, people will stop bringing it up."