In order to convince physicians of a hypothesis, investigators must go through a series of research steps. We first look for associations. Then, we look for prediction (in the example today, elevated CRP levels predict coronary artery events). Finally, we look for efficacy in treatment. So the key question we have asked about the cardiac inflammatory hypothesis is whether we can treat to lower the risk!

Two Studies Suggest a Protein Has a Big Role in Heart Disease

Reducing the levels of a certain protein secreted by the body may be as powerful a tool in slowing heart disease and preventing heart attacks and cardiac-related death as lowering cholesterol, two teams of researchers are reporting today.

The studies, being published in The New England Journal of Medicine, provide the strongest evidence yet that the protein – known as CRP, for C-reactive protein – plays a role in heart disease.

The participants were patients with severe heart disease who were taking high doses of statin drugs, which reduce both cholesterol and CRP. Lower CRP levels, the researchers found, were linked to a slower progression of atherosclerosis and fewer heart attacks and deaths. And this effect was independent of the effect of lowering cholesterol.

“What we now have is hard clinical evidence that reducing CRP is at least as important as lowering cholesterol,” said Dr. Paul Ridker of Brigham and Women’s Hospital in Boston, the lead author of one of the studies.

But other heart disease researchers cautioned that more work was needed to prove that CRP directly causes heart disease. And most agreed that because the new studies involved only people with severe heart disease, it remained unknown whether healthy people would benefit from reducing their CRP levels.

Still, the study investigators said they suspected that the results would be shown to apply more broadly. If they are correct, a huge new market for the already popular statins could be opened among people whose cholesterol levels are normal but who have high levels of CRP. Of people stricken by heart attacks, half have normal cholesterol readings.

Several caveats – first, cardiac inflammation is probably different from inflammation elsewhere. Classic anti-inflammatory drugs do not decrease the risk (and from recent reports may increase the risk). Second, we still do not really understand the basic biological mechanisms involved. Until we better understand the basic science, we are probably treating crudely. I look forward to more specific studies in the future.

These studies will not change my practice, since I am currently treating all coronary artery disease patients with statins. The big question is whether we will screen healthy adults for elevated CRP in the future. We await that research as the cardiac inflammatory response story unfolds.

Related posts:

1. C reactive protein!
2. More on CRP as a risk factor
3. More evidence for statin use in diabetes
4. Inflammation and the heart
5. Pass the beans and olive oil

Related posts brought to you by Yet Another Related Posts Plugin.