Former President Bill Clinton Hospitalized.

Former President Bill Clinton was taken to a Manhattan hospital late this afternoon and two stents were installed in one of his coronary arteries.

Clinton, 63, who had a quadruple heart bypass operation in 2004, complained of brief episodes of chest discomfort over the past few days, even while at rest, said his cardiologist, Dr. Allen Schwartz, chief of cardiology at New York City's Columbia Presbyterian Hospital.

Schwartz performed an angiography, finding no evidence of a heart attack or damage to Clinton's heart.

Today's procedure "makes him less susceptible to future heart attacks," Schwartz said. "His prognosis is excellent."

Pictures taken of Clinton's arteries and of bypass grafts he received four years ago revealed that one of the grafts was blocked. Because of that problem, doctors placed two stents in his carotid artery. A stent is a wire mesh tube used to prop open an artery.

The blockage was typical of the "natural history" of bypass treatment, which has a 10 to 20 percent failure rate five years after the surgery, according to Schwartz.

"This was not a result of his lifestyle or diet, which have been excellent," he said, adding that Clinton is "in excellent condition, as evidenced both by what he does and objective testing."