Democratic candidate Bernie Sanders has been hospitalized in Las Vegas due to chest pains, ABC reports. 

Jeff Weaver, his senior adviser, explains, “During a campaign event yesterday evening, Sen. Sanders experienced some chest discomfort. Following medical evaluation and testing he was found to have a blockage in one artery and two stents were successfully inserted.”

The senator’s surgery was successful, and he will now spend a few days resting. He has canceled several upcoming campaign events and appearances in order to do so.

Senator Sanders is 78.