The campaign said they were cancelling Sanders' events and appearances "until further notice".
The medical problem Sanders experienced - while it can be serious if untreated - is one of the most common afflictions in men his age. And the procedure he underwent is one of the most routine performed by cardiologists.
"It's an in-and-out procedure and can take as little as 30 minutes," said Allen Taylor, chair of cardiology at MedStar Heart & Vascular Institute. "Many patients go home the same day. And the outlook is often very good."
Coronary arteries - arteries that feed blood to the heart muscle - can become blocked over time with the buildup of fatty deposits or plaque. As the artery narrows, it reduces blood flow and can cause chest pains. Heart attacks happen when that blood flow to a part of the heart becomes completely blocked.
So when a patient like Sanders complains of chest pains, doctors usually perform an angiogram to diagnose the problem, said Elizabeth Klodas, a cardiologist in Minneapolis. That means inserting a small catheter - about the thickness of a cooked piece of spaghetti - into an artery in the patients' wrist or groin. That catheter goes up to the heart area, where it can inject dye into the coronary arteries, allowing doctors to see them through x-ray.
"That gives you a road map and shows you were the blockages may be," Klodas said. Once doctors identify where the problem is, they can manoeuvre a balloon-tipped tube to the site of the blockage. The balloon is inflated, opening the artery back up so blood can fully flow again. The stent is a tiny wire mesh tube - "kind of like chicken wire," Klodas notes - that expands with the balloon, but stays in place permanently after the balloon and catheter are deflated and withdrawn. The stent is what keeps the artery propped open, so blood can flow to the heart muscle for years.
"This is a common procedure. It's very safe. People recover quickly," said Steven Nissen, a cardiologist at the Cleveland Clinic. "I've treated businessmen who go back to work the next day. I've had patients in the US Senate who have gotten right back to work. Although if Bernie were my patient, I might tell him not to work 16 hours a day for a little while, just to make sure recovery goes well."
At 78, Sanders is the oldest candidate among the candidates running for the Democratic nomination. Sanders' doctor released a letter during the 2016 campaign showing he had history of elevated cholesterol but no indication of heart disease at the time.
Sanders often jokes about his age at town halls and meeting with voters. But age is one of most dominant factors in heart disease - along with other factors family history, cholesterol level, blood pressure, obesity and diet. And Sanders' heart problem may revive the topic of age among Democratic Party voters, who will choose in coming months whether to nominate a candidate from among the three over the age of 70 or from the new younger generation of leaders also running.
