If someone told you you were "five years from a heart attack" they lied

that's not how it works

in a stable person (ie, not actually having a heart attack) stents help symptoms (a little better than medicines, but even that is debatable -- see Orbita trial). Medicines and lifestyle changes prevent heart attacks -- see Courage and Ischemia trials

cath labs are in fact about keeping you from dying once you have a heart attack. The other stents for stable disease like you had are nice -- you feel better faster with fewer medicines that without, but not main thing

source: not going to appeal to authority. See trials mentioned above, or ACC guidelines on management of CAD