Millions of people worldwide have at least one drug-eluting stent in their bodies, and according to the American Heart Association, stenting procedures are fairly common in the United States; currently about 70 percent of coronary angioplasty procedures also involve stenting.
Cardiologists said the idea that Clinton would have chest pains now is not surprising, considering his previous heart problems.
"Coronary disease is a chronic condition that is not 'cured' by bypass surgery," said Dr. Steven Nissen, chairman of Cardiovascular Medicine at the Cleveland Clinic. Nissen said that many patients develop chest pain within five to 10 years after their bypass operations.
Still, not all of these patients have chest pain that is severe enough to warrant a stent. "Probably only 10 to 20 percent will have significant enough symptoms to require stenting," said Dr. Fred Feit, associate professor of cardiology at New York University.
When the news first broke, ABC News' George Stephanopoulos reported that Clinton had been feeling "tired" and had been fighting a cold.
In the past, Clinton has been overweight and had a notoriously bad diet of fast food and donuts.
Just three years before his bypass surgery in 2001, Clinton's cholesterol level was high at 233 and his LDL, or "bad" cholesterol, was very high at 177, so he began taking Zocor, a statin drug, to lower it.
At some point, Clinton stopped taking Zocor, apparently on his own, according to a report in The New York Times.
But when he was admitted to NewYork-Presbyterian Hospital/Columbia University Medical Center on Sept. 3, 2004, for coronary bypass surgery, his LDL was still 114.
"The most important prognosisticator is what is going on in the muscle before the operation," said cardiologist Resar.
After Clinton's bypass surgery, "his function was completely normal and remains good," said Resar.
"What may have happened is one of the bypass grafts developed a blockage or became totally occluded [blocked] or a new blockage developed beyond where the the original bypass was inserted into the artery," he said.
The risks of these blockages are usually higher if the damage has occurred within the original bypass.
After the procedure, patients must take at least one blood-thinning agent, such as aspirin or clopidogrel, to reduce the risk of blood clots developing in the stent and closing off the artery. A few recent studies suggest that blood clots could develop more than a year after stent placement in the drug-eluting stents.
Doctors said Clinton would likely be discharged tomorrow and resume most of his actvitites.
Dr. Steven R. Bailey, president of the Society for Cardiovascular Angiography and Interventions, told MedPage Today that coronary artery disease is not a single event.
"Bypass surgery does work," he said, "but we're dealing not with an event, but a disease, and it does progress."
Bailey said Clinton paid attention to his symptoms and got quick medical attention, and, therefore, is a good model for others.
ABC News' Karin Halperin contributed to this report.