"Contrary to recent rumors I have not kicked the bucket yet. I am alive and well," the 56-year-old UFC Hall of Famer said in a statement to TMZ Sports.

"Special thanks to the amazing staff at Cedars Sinai Hospital. From the ER to cardiac ICU thanks for taking care of me."

"I’m one of those people that has crazy thick blood and nominally high bad cholesterol. Unfortunately, those 2 factors combined to create a nice clot occluding my Diagonal artery."

Couture continued, "The Cath lab at Cedars got right on it, cleared it out and placed a stint in its place."

Couture is thanking his fans for the love and support -- and dropped these words of wisdom -- "Live your lives to the fullest. You never know when you’ll draw that last breath in!"

As for Randy's health, his rep tells TMZ Sports ... the UFC legend had emergency surgery after being admitted to the hospital.

Here's the whole story ...

"During a workout at Randy’s LA training home Unbreakable Performance in West Hollywood, CA, Randy experienced discomfort in what he initially thought was an offset rib or vertebrae."

"He tried working on a roller to relieve the problem -- but that was not successful.  Incredibly, Randy finished the entire workout while likely having the beginnings of a heart attack. Shortly thereafter, he drove home and attempted to rest. When the radiating chest pain did not cease, he recognized something was wrong."

"He proceeded to walk multiple blocks to a nearby emergency room rather than battle Los Angeles traffic. Upon his arrival, after an EKG, the medical staff informed Randy he had a heart attack, and would require immediate surgery to resolve the issue."