Peter Wilson, 61, from Livingston, was stunned when a CT scan revealed a blockage in one of the arteries to his heart.
The scan had been carried out as part of a project funded by the British Heart Foundation (BHF) to find new ways of preventing heart attacks.
Mr Wilson has now made changes to his lifestyle, and has taken on a 60-day fundraising challenge to support the BHF ahead of its 60th anniversary.
“I cannot put into words how the ground below my feet disappeared when I received the results of my scan,” he said.
"It was a major shock. Up until then, I thought I had a pretty healthy lifestyle. I had even bought a new bike during the first lockdown and had cycled over 900 miles in and around my home town during that time.
"It had helped me lose weight and having lost more in the first part of 2021, I had no concerns about my general health when I volunteered to take part in the Scot-Heart 2 trial.
"I was pretty sure my attitude to eating sensibly and taking regular exercise meant I wouldn’t be at risk of heart related disease. So, when I got the results in March, I was really taken aback.”
Narrowed and or blocked arteries are the underlying cause of coronary heart disease - Scotland’s single biggest killer. On average, 18 people die each day in Scotland from coronary heart disease.
Mr Wilson has said he does not want to “take his health for granted”.
“Looking to the future and keeping positive, this study has shown me that I need to do more to look after my heart,” he said.
He has increased his exercise regime and is considering his diet, and taking advice from clinicians.
Mr Wilson and his family, including wife Olive and daughter Emma Jane, aim to walk, run and and cycle 600 miles in 60 days.