What gives? How can someone with high blood cholesterol levels for 30+ years end up with clean arteries, if indeed there is any causation between blood cholesterol levels and plaque accumulation. ... Perhaps actual blood cholesterol levels have no cause of heart disease on their own a-priori. And, if any of these crazy hypotheses are true, then how can a health system prescribe drugs like statins so casually and routinely to anyone with cholesterol over 230? This is particularly true, when the long term side effects of such drugs must still be unknown.
Lots of questions -- some scientific, some health-plan political... But mainly I am looking for just straight talk on this whole cholesterol/heart disease issue.
You ask a lot of good questions. Let me paraphrase them for ease of presentation.
1. How do statins help in heart disease - through lowering the cholesterol level or some other mechanism?
It's not clear - this is one of those topics where the pendulum of the literature swings back and forth, and I can't say that I've followed every swing. Some hold that statins lower cholesterol, cholesterol causes heart disease, and that's it (though all the details of what the worst cholesterol particles actually are, and how they work their deadly magic, are yet to be fully worked out). Others think that statins are "pleotropic" - i.e. they work in multiple ways, e.g. by reducing inflammation.
2. How could you have high cholesterol and still have clean coronaries?
It's quite possible. I would imagine pretty common. That's why one of the biggest statin-related controversies hasn't really hit the lay press yet. It's all about when to give the medicines. Should everyone be on a statin if their cholesterol is above a certain level ("treat to target," or what I think of as the "statin in the water" approach), or should a statin be used only if a patient's risk of coronary artery disease is above a certain level ("tailored treatment")? A recent study in the Annals of Internal Medicine supports the latter, but no one really does this yet since the guidelines of the major doctor groups favor the former.
3. How do I know if I need to take medicine for cholesterol?
One way to think of it is this: statins lead to a reduced risk of coronary artery disease. Great. But this only matters really if your ABSOLUTE RISK, before statins, is something that you, or your doctor, are concerned about. If your 10-year risk of heart disease is 1%, and the statin reduces it to 0.1%, that's a 90% risk reduction, but maybe you don't care about a 1% risk. (I might not.) One way to calculate your risk is the Framingham risk calculator.
4, Do clean coronary arteries on a coronary CT scan (i.e. a low calcium score) mean I can't have blockages in the heart arteries?