Former President Bill Clinton had two stents placed in his arteries yesterday after being hospitalized with chest pain.

What's a stent, you ask?

The mesh metal tubes work as a scaffolding to keep clogged arteries propped open. The procedure is so common, about 1 million are done each year in the United States.

We gave you the scoop on stents, about cardiologists' debates over when they are necessary and a local controversy about hundreds of patients who may have received stents when they didn't need them.

And last month in this live chat with Dr. Claudia Hochberg, an interventional cardiologist at Boston Medical Center, to answer your questions on the ABC's of stents.

Here were a couple of the most common question and answers: (Or replay the entire chat with this link.)

Q: Are there different kinds of stents? What's the best kind to get?

A: Claudia Hochberg:
There are different kids of stents and the type of stent that is best for a particular patient depends on multiple factors. Your doctor will decide what type of stent to use based on your clinical history, the lesion type and location and the your ability to take blood thinning medicines after the procedure. Stents basics are that there are two types, drug coated stents and bare metal stents (just metal with no medicine)

Q: What percent blockage in an artery is considered the cutoff for intervention (need for stent)?
 
A: Claudia Hochberg:
Generally speaking, a blockage of less than 70% is not thought to be hemodynamically significant and therefore is not treated with stents. The exception to this is a blockage in the left main coronary artery which is a big vessel that branches into the two arteries that feed the left side of the heart. There a blockage of 50% or greater demands treatment (and that treatment has historically been surgical)

Got more questions? Ask away and we'll get them answered.

AP photo