The European Society of Cardiology estimates a 50 percent reduction of coronary events if you can stabilize soft, vulnerable plaques (1). We are often led to believe that plaques you can see on an angiogram are “killer” plaques. It’s true that if they are large enough to obstruct blood flow, they will decrease oxygen transfer to the heart muscle cells making them more tired with less effort.
This is the definition of stable angina. It simply means it takes less effort to over-exert the heart muscles before they fatigue. However, you need approximately a 90 percent total obstruction of the blood vessel to develop stable angina. These plaques account for most of the plaques you might find in an angiogram. This is why if you take an angiogram, you are often immediately wheeled into the operating room to have a stent put into the artery with the belief you are only seconds away from an immediate heart attack and death.
However, the same angiogram can’t see a few plaques (because they are so small), known as the soft, vulnerable ones. When soft, vulnerable plaques rupture, then you have the death and disability (i.e., damaged heart tissue) that truly characterize heart disease. Technically, this is called an acute coronary event, and it has very little to do with the stable plaques that can cause angina. It is this small number of “rogue” soft, vulnerable plaques that are the true killers in heart disease (2,3).
The ultimate cause of plaque rupture is cellular inflammation inside the plaque. Cellular inflammation degrades the fibrous external coating of the plaque. Usually inside these soft, vulnerable plaques are also a lot of macrophages engorged with lipids. This is called the “necrotic core”. When the plaque bursts, these lipid pools are released into the bloodstream causing platelet aggregation and the rapid blockage of the artery resulting in a complete restriction of blood flow (as opposed to a limited restriction of blood flow with a typical stable plaque that will never rupture). It is estimated that about 75 percent of all coronary events are caused by ruptures of the soft, vulnerable plaques (2).
As I mentioned above, the really scary part of this story is that there is no type of imaging technology that can detect dangerous soft, vulnerable plaques. In essence, you don’t know if you have them or not. This is why the prediction of impeding cardiovascular events remains a guessing game. Even more interesting is that these soft, vulnerable plaques seem to form rather quickly (in about 10 years) as opposed to growing slowly over a lifetime (4). Moreover, the rate of growth of these soft, vulnerable plaques is strongly correlated with increasing insulin levels in the blood (4).
So what does this mean for people who don’t want to die from a sudden rupture of soft, vulnerable plaques that can’t be detected? The first thing is to reduce the inflammation within the plaque. Surprisingly, there is only one clinical study that has ever been published that addressed this question, and it used fish oil (5). This study indicated that if you give patients relatively high doses of fish oil, you could see a definite remodeling of the soft, vulnerable plaques in about 40 days compared to subjects taking a placebo composed of safflower oil. The plaques in the subjects taking the fish oil became less inflamed, had higher levels of omega-3 fatty acids, fewer macrophages and more well-formed fibrous caps compared to those taking the placebo. So taking a therapeutic level of fish oil for a lifetime seems to be a good way to reduce the rupture of these plaques.
Another way to potentially reduce their formation in the first place is lower insulin levels. The reason insulin levels are elevated is because organs, such as the adipose tissue, the liver and the muscles, are also inflamed (6). The best way to reduce that systemic inflammation is to follow the anti-inflammatory diet and take therapeutic levels of fish oil for a lifetime. Your success is best measured by the AA/EPA ratio in the blood. Call me crazy, but I think that’s what I have been recommending for the past 16 years (7).References:
- Yia-Herttulala S, Bentzon JF, Daemen M, Falk E, Garcia-Garcia HM, Merrmann J, Hoefer IM, Juekma JW, Krams R, Kwak BR, Marx N, Maruszeqica M, Newby A, Pasterkamp G, Serruys PWJC, Waltenberger J, Weber C, and Tokgozoglu L. “Stabilization of atherosclerotic plaques.” Thomobosis and Haemostasis 106: 1-19 (2011).
- Schaar JA, Muller JE, Falk E, Virmani R, Fuster V, Serruys PW, Colombo A, Stefanadis C, Ward Casscells S, Moreno PR, Maseri A, and van der Steen AF. “Terminology for high-risk and vulnerable coronary artery plaques. Report of a meeting on the vulnerable plaque.” Eur Heart J 25: 1077-1082 (2004).
- Lloyd-Jones D, Adams R, Carnethon M, De Simone G, Ferguson TB, Flegal K, Ford E, Furie K, Go A, Greenlund K, Haase N, Hailpern S, Ho M, Howard V, Kissela B, Kittner S, Lackland D, Lisabeth L, Marelli A, McDermott M, Meigs J, Mozaffarian D, Nichol G, O'Donnell C, Roger V, Rosamond W, Sacco R, Sorlie P, Stafford R, Steinberger J, Thom T, Wasserthiel-Smoller S, Wong N, Wylie-Rosett J, and Hong Y. “Heart disease and stroke statistics--2009 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee.” Circulation 119:480-486 (2009).
- Hagg S, Salehpour M, Noori P, Lundstrom J, Possnert G, Takolander R, Konrad P, Rosfors S, Ruusalepp A, Skogsberg J, Tegner J, and Bjorkegren J. “Carotid plaque age is a feature of plaque stability inversely related to levels of plasma insulin.” PLoS One 6: e1824 (2011).
- Thies F, Garry JM, Yaqoob P, Rerkasem K, Williams J, Shearman CP, Gallagher PJ, Calder PC, and Grimble RF. “Association of n-3 polyunsaturated fatty acids with stability of atherosclerotic plaques: a randomized controlled trial.” Lancet 2003 361: 477-485 (2003)
- Sears, B. “Toxic Fat.” Thomas Nelson. Nashville, TN (2008).
- Sears B. “The Zone.” Regan Books. New York, NY (1995).