Senator Bernie Sanders was hospitalized and treated for an artery blockage and is canceling his events for the coming days, a campaign official said on Wednesday.
“During a campaign event yesterday evening, Senator Sanders experienced some chest discomfort,” Jeff Weaver, a longtime adviser to Mr. Sanders, said in a statement. “Following medical evaluation and testing he was found to have a blockage in one artery and two stents were successfully inserted. Senator Sanders is conversing and in good spirits. He will be resting up over the next few days. We are canceling his events and appearances until further notice, and we will continue to provide appropriate updates.”
Mr. Sanders, 78, was traveling for a gun forum in Las Vegas that other candidates were also scheduled to attend. He was to travel to California later this week. He is currently recovering in a Las Vegas hospital, the campaign said.
Mr. Weaver read the statement to staffers on a quickly assembled conference call at 10:30 a.m. Eastern time, according to an aide on the call. No one on the staff asked questions following his statement, which the aide said Mr. Weaver read in measured tones.
One campaign aide, referring to Mr. Sanders, told The New York Times on Wednesday morning: “He feels better than ever because that’s how people feel after they get a stent and there’s more blood flow.”
Mr. Sanders has kept up a brutal schedule on the campaign trail, typically holding multiple events in several cities a day. Over the weekend, he held several events at colleges in New Hampshire. Following his trips this week to Nevada and California, he had been expected to travel to Iowa this weekend, according to a campaign aide.
Mr. Sanders on Tuesday night visited an outdoor memorial in Las Vegas that’s dedicated to victims of the city’s 2017 mass shooting. He also hosted a grass-roots fund-raiser at the Shiraz restaurant.
The restaurant’s owner, Raja Majid, said in a phone interview that Mr. Sanders spoke to a crowd of about 250 people. As he began taking questions from the audience, he asked a staff member, Ari Rabin-Havt, a deputy campaign manager, for a chair, an unusual request from a candidate who typically stands or paces onstage. “Ari, can you do me a favor?’’ Mr. Sanders said, according to a video posted on Periscope. “Where’s Ari? Get me a chair up here for a moment. I’m going to sit down here. It’s been a long day here.”
It is unclear whether Mr. Sanders will be able to participate in the next debate, scheduled for Oct. 15 in Columbus, Ohio.
Mr. Sanders’s allies quickly downplayed his procedure. RoseAnn DeMoro, a former leader of a nurse’s union and longtime Sanders surrogate, said “there are numerous presidents who have had heart problems and heart problems far worse” than what Mr. Sanders underwent Wednesday, adding that a stent “can improve one’s health.”
But many Democratic voters have long expressed discomfort with nominating a candidate in their 70s, and Mr. Sanders’s heart difficulties will likely refocus attention on age as a factor in a race where the three leading candidates are in their 70s. A Pew survey in May indicated that only 3 percent of Democratic voters believed the best age range for a president to be in was in their 70s. Forty-seven percent of those surveyed said they preferred a president in their 50s. One of Mr. Sanders’s chief rivals, Joseph R. Biden Jr., who is 76, has drawn attention to his age because of his sometimes rambling discourses and uneven answers at debates.
Mr. Sanders, who lost to Hillary Clinton in the 2016 Democratic primary, has been among the leaders in the Democratic primary since he entered the race in February. He was running second to Mr. Biden in most early polls but has fallen into third in recent weeks — behind Mr. Biden and Senator Elizabeth Warren — in several polls of early nominating states.
The Sanders campaign had planned to go on air with his first television ads of the campaign this week in Iowa, announcing a two-week $1.3 million buy on Tuesday. An ad tracking service, Medium Buying, said on Wednesday that Mr. Sanders began postponing those ads. The reason for the cancellation was not immediately known. Even as late as Tuesday night, Faiz Shakir, Mr. Sanders’s campaign manager, was talking excitedly about the ad buy on a call with supporters.
On the trail, Mr. Sanders’s events are usually high-energy affairs, where he regales enthusiastic crowds with his calls for “Medicare for all” and tuition-free public college and rails against the corporate and Washington elite. In recent weeks, he has struggled with a hoarse voice that emerged during a swing through Iowa and Colorado and then worsened heading into the last debate in mid-September. He subsequently canceled several events last month to “rest his voice” but has since returned to the campaign trail.
In March, he hit his head on the edge of a glass shower door, requiring seven stitches.
The onetime captain of his high school track team, Mr. Sanders has tried to project an image of fitness as a candidate. He pitched in the softball game his campaign staged over the summer on Iowa’s “Field of Dreams,” and his aides have released other images of him playing catch or basketball. When he’s on the road, Mr. Sanders often heads to an open gymnasium to shoot baskets.
Stents are tiny metal tube-shaped cages used to widen arteries in which blood flow has become impeded. They are inserted into coronary arteries when patients are suffering from angina, pain that results from clogged vessels, or heart attacks, in which blood flow is completely blocked.
The stent is inserted into the artery after it is reopened with a balloon. It is threaded to the site of the blockage through a small incision elsewhere, often the thigh.
Stenting is common in the United States — there are at least 600,000 such procedures a year, perhaps almost one million. It is usually uncomplicated, and patients return home within a day or two. If the heart muscle was damaged by the blockage, then recovery may take longer.
Mr. Sanders’s campaign did not provide details on what precipitated the episode or whether he had suffered a heart attack.
Mr. Sanders has not yet released his medical records though he has vowed to do so. During his first presidential run, he released a letter from his doctor declaring that he was in “very good health.” The letter stated that Mr. Sanders had suffered several ailments during his life, including gout, diverticulitis, superficial skin cancers and laryngitis from acid reflux. The letter also said Mr. Sanders had normal readings for blood pressure, pulse and blood count and that he had no history of cardiovascular disease.
Not long after news of Mr. Sanders’s hospitalization emerged, several of his rivals for the Democratic nomination sent good wishes his way.
“Glad to hear my friend @BernieSanders is doing well and in good spirits — wishing him a speedy recovery,” Senator Cory Booker of New Jersey wrote on Twitter.
“Bernie’s fighting spirit will get him through anything and everything,” said Senator Amy Klobuchar of Minnesota. “Good to hear he is doing better and look forward to seeing him soon.”
Ms. Warren began an appearance in Las Vegas on Wednesday by bringing up Mr. Sanders. “I know everyone here wishes him well, wants to see him strong and back on the trail as soon as possible,” she said. “I’ve called, I’ve texted and I’ll send your best wishes if that’s O.K. with everyone.”
Shane Goldmacher, Gina Kolata, Thomas Kaplan and Matt Stevens contributed reporting.