My uncle just had bypass surgery. One of his arteries was completely blocked. He went to the hospital a few days ago with chest pain. They did an angiography and found the blocked artery. He had an emergency bypass surgery. He's recovering now and a little tired but doing just fine.
Apparently, in his surgery, they take blood vessels from one part and replace the blocked part of the artery with clear blood vessels. Of course, my uncle has to be careful with his diet and also get regular exercise from now on. But he won't be having heart issues caused by poor blood flow anymore.