Background
It is said that there are two kinds of coaches in professional sports, those that have been fired and those that will be fired; Pithy and generally true. The same argument can be applied to the treatment of Coronary Artery Disease. There are two types of arteries in someone having a heart attack, the one causing the problem and the ones that may cause the next one. So, the approach to heart attack can be summarized as Rescue from the one that's here. Prepare for the one that's coming and Prevent it if you can. There was no rescue until clot busting drugs (thrombolytics) and they don't work all that well. Balloon angioplasty made all the difference. However, the tools and techniques of the early version were primitive and not completely reliable. Therefore, the prevailing behavior was to follow Royal's Law. You dance with the one what brung you. The site in the artery that is causing a heart attack and leave the other narrowings, that you may happen upon, alone. Time and technology have moved on. The success and reliability of reforming diseased arteries are such that some physicians argue for repair of all potential problems in the same setting. Therefore, if heart attack has brought you to attention, "fix" all other narrowings that are found at the same time. On the surface, this may seem to be a simple decision. Find narrowings. Fix narrowings. Rescue and prevent at the same time. Unfortunately, as usual, simple is misleading and essentially incorrect. The knowledge that coronary artery disease is present is like a mountain road with the sign, beware falling rocks. Attacking the rocks found on the road doesn't protect anyone from the next one to fall. So too, treating a narrowed segment of artery that is not the source of current difficulty is not likely to prevent anything. It just makes the road easier to pass. The other side of the argument is that the narrowings present are a source of danger if another heart attack comes along. The heart muscle that they are restricting by their presence may not be able to give its all should it be needed. People who have a heart attack may be in danger of another. Therefore, the rocks fallen or the narrowing present should be cleared if it can be done safely.
Question
Most cardiologists would agree that the doctor's eye alone should not be the arbiter of what narrowing needs attention. When that is the only guide available, a "stress test" of each narrowing that can be done at the same time as the angiogram (called Fractional Flow Reserve or FFR) reduces how often treatment is chosen and makes the whole process safer. So, the next logical question is, if the doctor has the angel of FFR on his or her shoulder, is it safe and useful to address more narrowings than just the one what brung me.
Study
A group of physicians and institutions throughout Europe convinced almost 900 people having a heart attack to participate in a study.(1) The basics were that if one of the arteries not causing the heart attack exceeded 50% narrowing, they could participate. In those who did, FFR was measured and some had the artery repaired, the remaining did not. The headline is that with the guidance of FFR, people who had everything done at the same time benefited. The longer version starts with the fact that very few people who participated died of their heart attack. That is very reassuring. In the people who got everything done at the same time, there did not appear to be any harm done by the extra work. The only real benefit that they had was that fewer had to have something done later. Having everything done at the same time didn't change survival (it was too good to get much better) or prevent heart attacks.
Impact and analysis
If you're having a heart attack and in pretty good shape going in, your doctor can take care of any extra narrowings at the same time as long as there is proof that they need taking care of. More importantly, if he or she doesn't, you don't lose anything. The observation that some of the people who didn't get everything done at the same time got something done later is not very convincing. Not all that many ended up needing anything extra and it's hard to be certain that they really needed it. The take home message is that people having a heart attack who were getting timely treatment did very well. With respect to any other narrowings that may be present, there is neither compelling reason to do something nor to avoid it.
Keywords: Heart Attack, Myocardial Infarction, Stent, Cardiovascular Disease
http://www.nejm.org/doi/abs/10.1056/NEJMoa1701067?query=NC
1. Smits PC, Abdel-Wahab M, Neumann F-J, Boxma-de Klerk BM, Lunde K, Schotborgh CE, et al. Fractional Flow Reserve-Guided Multivessel Angioplasty in Myocardial Infarction. New England Journal of Medicine. 2017.
