The Vermont independent senator, 78, was hospitalized Tuesday after experiencing chest pains at a campaign stop in Nevada. He was treated for what his 2020 presidential campaign described at the time as a blockage in one artery.

But a statement from Sanders’ doctors released through the campaign on Friday said Sanders “was diagnosed with a myocardial infarction,” a medical term for a heart attack.

“The Senator was stable upon arrival and taken immediately to the cardiac catheterization laboratory, at which time two stents were placed in a blocked coronary artery in a timely fashion,” the doctors’ statement said. “All other arteries were normal.”