Which part needs to be explained? I think I understood the comment and I’m not in the industry. AED is an initialism for the electrical shock device you can use to (maybe) reboot the heart’s OS when it locks up. Catheters are some kind of tube that gets implanted to bypass a non-functional part of the heart. Catheter procedures improving caused the change, not AEDs (apparently), so it’s somewhat misleading to show an AED instead of something about catheters.

PCI (Percutaneous Coronary Intervention, performed in a catheterization laboratory) has become the usual first-line treatment for acute heart attacks.

It's much more effective than previous treatments (essentially clot-busting drugs, blood thinners, and bedrest), particularly since Drug-Eluting Stents arrived in the early 2000s.

There is a procedure called a "catheterization" (hence "cath lab").

I have two stents in my heart. They went in with a catheter through an artery in my wrist. They found the places in my heart where the arteries were 80% to 90% blocked, and placed stents there. They said I was five years from a heart attack.

This was an outpatient procedure. I went home that night.

The worst part of it, for me, was that they put a serious tourniquet on my wrist, because once they took the catheter out, I had an open artery. My wrist felt like I lost a bar fight. It ached for a month.

This is so much better than having a heart attack.

How did they know I needed this? I talked to a cardiologist. He told me that, as you age, your athletic performance drops slowly, over decades. That's normal. What's abnormal is when you suddenly can't do something you were able to do a month ago.

So I paid attention when I realized, hey, a month ago I didn't get this winded playing ultimate frisbee. A month ago I recovered faster when I was winded.

So I told that to my GP. He ordered a cardiac stress test for me. This basically is hooking you up to an EKG, putting you on a treadmill, running the treadmill faster and harder until you drop, and watching what your EKG does. If the shape stays the same except faster, you're good. If the shape changes, that's part of your heart not getting enough blood under load. My shape changed. So they ordered the catheterization for me.

So cath labs are about preventing the heart attack, not keeping you from dying once you have one. Not dying is good. But not having it at all is better. I think that may have been the GP's point.