(CNN) - Former President Bill Clinton's trip to a New York hospital was his second procedure since open-heart surgery in 2004. The 63-year-old, two-term president was taken to New York Presbyterian Hospital after complaining of what Clinton counselor Douglas Band said was "chest discomfort."
Fact Check: What prior heart issues has Clinton had?
– Clinton had a quadruple bypass in September 2004 after doctors discovered blockages in some of the coronary arteries that feed blood to the heart. Some of those arteries were more than 90 percent blocked, surgeons said after the procedure.
– In March 2005, doctors removed fluid and scar tissue that had developed in his left chest after the bypass surgery.
– Thursday's procedure inserted two stents - tubular pieces of scaffolding that support the artery walls - to one of the former president's coronary arteries.
– Stents are used to open up arteries that have become blocked or narrowed. Dr. Jonathan Reiner, who was former Vice President Dick Cheney's cardiologist, said Clinton's symptoms suggest one of the bypass grafts performed during his open-heart surgery had become blocked - a common problem, Reiner said.
– The average hospital stay for patients having a stent implanted is two days or less, and some patients may not need to stay overnight, according to the National Institutes of Health.
Read the bottom line after the jump:
Bottom line: The procedure Clinton underwent Thursday is a common one, according to the American Heart Association. His office said the former president, now a top U.N. official for earthquake-ravaged Haiti, was "in good spirits" and expected to resume his work on Haiti soon, his office said.