Presidential hopeful Bernie Sanders on Wednesday canceled all appearances until further notice after the 78-year-old senator underwent a procedure for an artery blockage.
In a statement, the campaign advisor Jeff Weaver said Sanders "experienced some chest discomfort" during an event Tuesday. Tests found a "blockage in one artery," and Sanders had two stents inserted, he said.
"Sen. Sanders is conversing and in good spirits. He will be resting up over the next few days," Weaver said. "We are canceling his events and appearances until further notice, and we will continue to provide appropriate updates."
In a tweet later Wednesday, Sanders said he is "feeling good." He used his situation to make the case for government-run universal health care, his signature campaign policy.
The tweet from Sanders' campaign account said, "None of us know when a medical emergency might affect us. And no one should fear going bankrupt if it occurs. Medicare for All!"
Sanders is the oldest presidential candidate seeking to challenge President Donald Trump in 2020. The Vermont independent is two years older than former Vice President Joe Biden, who has led most national and state primary polls despite concerns about his mental sharpness.
Sanders is five years older than the 73-year-old Trump, who is the oldest person to be elected as a first-term president.
A stent is a tiny wire mesh tube that props open an artery and is left there permanently, according to the American Heart Association. Coronary arteries clogged by fatty plaque can reduce blood flow to the heart, causing chest pain and possible heart attacks if the blood flow is completely blocked.
The senator had committed to releasing his medical records before the primary voting contests started. During his 2016 presidential campaign against Hillary Clinton, the senator released a letter from his doctor saying Sanders was in good health and did not have a history of heart disease.
The Sanders campaign appears to have started canceling a $1.3 million ad buy slated to start Thursday in the first-in-the-nation nominating state of Iowa, according to NBC News. It only announced the television ad on Tuesday.
A Sanders campaign spokeswoman told CNBC the move is a "postponement." It was unclear if the ad changes were related to Sanders' health.
Sanders was set to appear at an MSNBC gun violence forum on Wednesday along with nine other candidates. He held a grassroots fundraiser in Nevada on Tuesday.
The senator's Democratic primary competitors sent him messages of support after his campaign announced the procedure. In tweets, Biden, Sens. Elizabeth Warren, D-Mass., Kamala Harris, D-Calif., Cory Booker, D-N.J., and South Bend, Indiana, Mayor Pete Buttigieg all wished Sanders a "speedy recovery."
Sanders has run for president promising a drastic political and economic overhaul. He has proposed plans including implementing a single-payer "Medicare for All" health care system, canceling all student debt and taxing the wealthy at higher rates.
Sanders is considered one of the top contenders for the Democratic presidential nomination. He has polled among the top three candidates in the vast majority of national and early state primary surveys.
On Tuesday, his campaign said it raised $25.3 million in the third quarter, a haul that will allow him to stay competitive in the primary contest well into next year.
— CNBC's Kevin Breuninger contributed to this report
— Correction: An earlier version misstated the age difference between Sanders and Biden. It is two years. An earlier version also mischaracterized the medical procedure performed on Sanders, according to his campaign.