(Reuters) - U.S. Senator Bernie Sanders, who is seeking the 2020 Democratic presidential nomination, has been treated for a blocked heart artery after experiencing chest discomfort, leading to cancellation of some planned campaign events.

The following are some facts about the artery-clearing procedure the 78-year-old from Vermont underwent and the prognosis for someone of his age following the treatment.

* PROCEDURE

Sanders underwent what is called an angioplasty to clear the blockage and had two stents placed in the artery, his campaign said. The procedure, which is done in a cardiac catheterization lab and typically takes about an hour, is one of the most common in modern heart medicine. In most cases, a balloon-tipped wire is inserted via a catheter through the wrist and threaded up into the artery clogged with plaque. The balloon is then expanded to clear the blockage. During the procedure, the patient is usually under what is called conscious sedation, doctors said.

* STENTS

Stents are tiny mesh tubes that are placed into the cleared artery to keep it propped open, allowing normal blood flow to the heart. In almost all cases, the stents are coated with a drug that helps prevent the formation of scar tissue that could lead to reclogging. Some form of imaging, such as intravascular ultrasound, is used to guide the procedure and to make sure the stents are appropriately sized for long-term durable results.

* MEDICATION

Patients who undergo artery-clearing procedures must then take blood thinners or platelet inhibitors to lessen the risk of formation of dangerous blood clots that can lead to stroke or heart attack. Depending on the patient, they would typically be on those drugs for six months to a year.

Most often, patients are given aspirin and Plavix, known generically as clopidogrel. Some newer drugs, such as Eli Lilly and Co’s Effient (prasugrel) or AstraZeneca’s Brilinta (ticagrelor) may also be used.

“For someone who had a heart attack and got a stent, we use those more powerful medications, assuming they are not at high bleeding risk,” said Dr. Deepak Bhatt, executive director of interventional cardiovascular programs at Brigham and Women’s Hospital in Boston.

* RECOVERY TIME

For a patient with chest discomfort, known as unstable angina, who has not had a heart attack, recovery time from angioplasty and stenting is remarkably fast. If there has been no damage to the heart, which is presumably the case with Sanders, a patient can be up and around in an hour and released from the hospital that same day or the next, doctors said. If the procedure is successful, there are no restrictions for physical activity.

“He could be on the campaign trail tomorrow, even at 78,” said Dr. Ashish Pershad, an interventional cardiologist at Banner – University Medicine Heart Institute in Phoenix.