The Role of CRP Testing in the Initiation of Treatment with Crestor
Posted Jan 11 2010 12:00am
The Harvard Health Letter recently published an article about the top ten health stories of 2009 (see: The top 10 health stories of 2009). One of the ten items focused on the value of C-reactive protein (CRP) testing so I thought that it would be useful to repeat this item here. Below is the passage from the article:
CRP: Ready to make an entrance? Late in 2008, results from the industry-funded JUPITER trial showed that people with normal LDL cholesterol levels (less than 130 mg/dL) but relatively high CRP levels (2 mg/L or higher) could cut their risk of having a heart attack or stroke in half by taking a high dose (20 mg) of a powerful statin drug, rosuvastatin (Crestor). CRP stands for C-reactive protein....Statin drugs are taken primarily to lower LDL levels, but this was added proof that they also calm inflammation. That first round of JUPITER results made a big splash, but it left room for debate about how CRP testing and lowering should fit into cardiovascular care. Subanalyses of the JUPITER data published in Lancet helped clarify if not completely settle matters. People in the trial who reached a very low LDL level (less than 70 mg/dL) cut their risk of having a cardiovascular "event"...by 55%. But those who achieved a sub-70 LDL and a CRP of less than 2 mg/L lowered their risk by 65%. And reaching a CRP of less than 1 mg/L lowered it by 79%. Many unanswered questions remain. What are the long-term consequences of taking high doses of potent statins like rosuvastatin? Might changes in diet, or increased physical activity, achieve the same thing? Still, the JUPITER results add to the evidence showing that cardiovascular disease is fundamentally an inflammatory process. The official LDL-centric guidelines haven't changed, but many doctors are going ahead and ordering CRP tests for their patients with cardiac risk factors, even if their LDL levels are normal. If two tests show the CRP level is high, they may prescribe a high dose of a potent statin.
Statins seem to have an anti-inflammatory effect, inflammation of the coronary arteries may have a causal effect in cardiovascular events, and CRP is a biomarker for inflammation anywhere in the body. Hence and for patients with cardiac risk factors such as being overweight or hypertensive, treatment with statins may be initiated even in the face of normal LDL levels. Measurement of CRP is certainly not novel or new. Why, then, does this "top ten" article describe CRP as ready to make an entrance. I think that the key point being made is that, as the results of the original JUPITER study and subanalyses are disseminated, a high CRP level has now become an actionable lab test for physicians and an effective drug, Crestor, is readily available to treat coronary artery inflammation.