Gupta said dating back to 2009, President Trump started to have "these tests that are actually looking for the presence of calcium in the blood vessels that lead to the heart."
"Steadily, up until just this past week when he had it performed again, those numbers have gone up," he said.
"When they get to a certain range ... that means he has heart disease."
Gupta then talked about his interaction Tuesday with President Trump's doctor, Navy Rear Adm. Dr. Ronny Jackson.
"It was interesting when I spoke to Dr. Jackson at first, he said, he passed all the tests with flying colors," Gupta said. "When I asked him specifically about that test, did he then concede that, in fact, the president does have heart disease."
"They're going to be increasing the medications, including the cholesterol-lowering medications to try and combat that, but there's no question, by all standards, by all metrics, anyway a doctor or cardiologist will look at it, the president does have heart disease."
Gupta said it's controllable with medications, adding that Trump needs to have his diet under control.
"But he does have heart disease," he said.