New York (CNN) -- Former President Bill Clinton has shown "no evidence of heart attack or damage to his heart," and his prognosis is excellent after undergoing a procedure Thursday to restore blood flow in one of his coronary arteries, according to his doctor.
Clinton, 63, was hospitalized at New York-Presbyterian Hospital's Columbia campus after experiencing brief periods of discomfort in his chest over several days, according to Dr. Allan Schwartz, the hospital's chief of cardiology.
Two stents were used to restore blood flow to a coronary artery Thursday after images revealed that a bypass graft -- part of a quadruple bypass surgery that Clinton underwent in 2004 -- was blocked, Schwartz said.
An electrocardiogram and a blood test showed no evidence of a heart attack, Schwartz said.
"He's in good spirits, and we hope to have him go home tomorrow," Schwartz told reporters Thursday night.
Schwartz said the need for the procedure had nothing to do with Clinton's post-bypass diet or exercise, which Schwartz called excellent. Rather, Schwartz said, this is "part of the natural history" of the bypass treatment.
"He really toed the line in terms of diet and exercise. He really followed the program," Schwartz said, adding he told Clinton that he'd be allowed to return to work Monday.
The stents have opened the artery that the blocked bypass graft was supposed to service, Schwartz said. Stents are tiny balloons that are threaded into a patient's heart vessels where they are inflated, pushing plaque against the vessel wall and increasing blood flow.
The graft's blockage isn't unheard of, because that particular type of graft has a 10 percent to 20 percent failure rate after six years, Schwartz said.
However, a bypass graft at a different artery -- the main artery in the front of Clinton's heart -- still looks "pristine," Schwartz said.
"We know from multiple studies that if that bypass is open at this point ... it will remain open," he said.