Two articles recently published in the New England Journal of Medicine indicate that lower CRP levels are associated with fewer heart attacks (myocardial infarctions), and suggest that reducing CRP levels with statins result in fewer cardiovascular events. CRP is a protein circulating in the bloodstream that is a marker for inflammation. When inflammatory processes are occurring, CRP levels rise. Inflammation is now thought to be an important process in the rupture of coronary artery plaques, an event that often causes sudden heart attacks; hence, increased CRP levels have correlated with the risk of cardiovascular events.
The articles describe newly-analyzed data from the PROVE-IT and REVERSAL trials, both of which compared outcomes in post-heart-attack patients using two different statin regimens - an aggressive regimen (80 mg per day of atorvastatin) and a moderate regimen (40 mg per day of pravastatin). Previously reported results had shown significantly reduced cardiac events (PROVE-IT) and slowed progression of coronary artery disease (REVERSAL) using the aggressive statin regimen.
Now, investigators from both trials report that the improved clinical outcomes in these trials were not only related to reduced LDL cholesterol levels achieved with the aggressive statin regimen, but were also independently related to reducing CRP levels to less than 2 mg/L. Thus, the beneficial results seen in both of these trials appear to have been related to CRP reduction, as well as cholesterol reduction.
DrRich comments
Evidence seems to be slowly but surely accumulating that reducing elevated CRP levels is important in preventing heart attacks in people who have coronary artery disease. The results from these two trials constitute the strongest such evidence to date. There is certainly enough evidence from these trials to encourage and accelerate ongoing efforts by drug companies to develop agents aimed specifically at reducing CRP levels.
However, using statins primarily to reduce CRP levels (especially in patients with adequate cholesterol levels) is going to remain controversial, at least for now. At least one large randomized trial to test this approach is now underway. In the meantime, for patients with only modestly elevated cholesterol levels, a high CRP level may be enough to tip the balance in favor of statin therapy.
