John Harold, president of the American College of Cardiology and a clinical professor of medicine at the David Geffen School of Medicine at the University of California, Los Angeles, said stents act like scaffolds to prop open blocked arteries from the heart and allow blood to flow normally, USA Today reported.
Harold, who was not involved with Bush's treatment, said placing stents is a much less invasive procedure than open heart surgery. Interventional cardiologists make small incisions in the wrist or groin and thread a catheter through a major artery up to the aorta.
Doctors use a balloon to open up the blocked artery, then the stent is unrolled and left in place to keep the artery open. Some stents also release drugs, some in continuous doses, which help prevent the artery from getting clogged again, Harold said.
Although, Bush, 67, is at an age that increases his risk of heart disease, he has been an enthusiast jogger and mountain bicyclist, and the former president had excellent blood pressure and cholesterol test scores.
Dr. John McPherson, a cardiologist at Vanderbilt University Medical Center in Nashville, said even a healthy lifestyle won't prevent all heart disease. The stent indicated Bush has an increased risk of heart attack, but managing his risk factors, such as his cholesterol and blood pressure, could reduce his risk.
A Bush spokesman said Tuesday the former president didn't experience symptoms of shortness of breath or chest pain but "the stent was necessary. His annual physical includes a stress test. Electrocardiogram changes during the stress test prompted a CT angiogram, which confirmed a blockage that required opening."
McPherson said a significant number of patients end up with stents after a routine physical as Bush did, because some patients who experience occasional chest pain or shortness of breath might not tell anyone until a doctor asks.
However, Steven Nissen of the Cleveland Clinic in Ohio, questioned if Bush really needed a stent because doctors typically place stents only in patients who experienced chest pain and sometimes stents themselves could become clogged up, causing greater problems.
"He did a 100-kilometer -- 62 miles -- bike ride," in May, Nisson told USA Today, "a feat impossible for someone on the verge of a heart attack. "How can a stent make him better?"
People without symptoms don't need annual stress tests, in which patients walk on a treadmill while doctors perform an EKG, Nissen added.
Bush likely "got the classical thing that happens to VIP patients, when they get so-called executive physicals and they get a lot of tests that aren't indicated. This is American medicine at its worst."