EDITORIAL: The statin stumper: Warning, new heart findings may flummox your doctor

April 15--Millions of Americans take statins to cut their risk of heart disease. Study after study has shown these drugs, introduced in the late 1980s, to be effective.

But how do they function? For years researchers believed that statins worked by lowering cholesterol in the blood. Over the decades the "cholesterol hypothesis" has been refined as doctors learned more about different types of blood cholesterol -- the dangerous LDL, and the protective HDL.Physicians began tailoring statin therapy to reduce LDL and raise HDL.

The drugs, along with advances in heart care and a national decline in smoking, worked spectacularly: While the rate of heart disease deaths continues to rise in most of the world, it has fallen significantly in the United States since the 1960s.

Still, a medical mystery lingers: The benefits of statins are proven, but the why remains in doubt. Recent studies of new (and more expensive) non-statin drugs that do the same thing that statins do -- reduce bad cholesterol and raise good cholesterol -- have not shown a similar benefit in preventing heart attacks. In some cases the newer drugs may have been associated with more heart attacks.

One researcher was blunt: "We had an agent that seemed to do all the right things. It's the most mind-boggling question. How can a drug that lowers something that is associated with benefit not show any benefit?"

Put simply: Reducing a patient's heart disease risk is not simply a matter of changing cholesterol levels.

A high level of LDL appears to correlate with the risk of having atherosclerosis, a build-up of plaque in the walls of arteries that can obstruct the flow of blood to the heart or brain. But that high level of LDL is not causing the artery-hardening disease by itself. If it were, those other drugs that reduce LDL should show the same benefits as statins -- that is, fewer heart attacks and less heart disease.

There is much to be discovered about how statins help people avoid heart attacks (and possibly strokes) by how these drugs affect blood vessels, blood and clotting.

This latest research suggests the primary way stains reduce heart risk is apparently not by changing HDL and LDL levels in the blood. Instead, cardiologists suspect that statins work through their beneficial effects on diseased artery walls rather than in the blood itself.

For physicians and researchers, the mystery of stains is another puzzler and a reminder that even the most cherished medical hypotheses may not stand up to intense scrutiny. Challenging assumptions is how medicine advances, how treatment improves.

For the pharmaceutical companies, the latest research means a trip back to the drawing board to develop new medicines to treat heart disease, especially for those patients who cannot tolerate statins.

And for patients? The essentials to avoid heart disease remain the same -- eat a healthy diet, exercise often, avoid tobacco, stay trim and keep your blood pressure under control.

And let's stress one warning: None of this research means you should stop taking statins. The drugs remain a mainstay of treatment for patients who have heart disease and in selected patients where the goal is to prevent heart disease.

But know this: Just because you have low LDL and high HDL, you're not home free. Based on your risk factors and medical history, you could need a statin. Ask your doctor if you should be taking a statin, and why.

Meanwhile, keep your cholesterol numbers in check. Remember, nearly 1 in 4 Americans dies of heart disease. It is still the leading cause of death in the United States.

How statins work remains a mystery. That they work isn't.

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