From the Guidelines
CRP is not recommended as a routine measurement for patients with stable coronary artery disease, as its association with cardiovascular events is uncertain and may not add to the prognostic discrimination achieved by considering standard clinical factors 1. When evaluating the role of C-reactive protein (CRP) in cardiac conditions, it is essential to consider the most recent and highest quality evidence. The 2010 study published in PLoS Medicine 1 found that the association between CRP levels and prognosis among patients with stable coronary artery disease is extremely uncertain due to multiple types of reporting and publication bias. Key points to consider when interpreting CRP levels in cardiac conditions include:
- Elevated CRP levels (typically above 3 mg/L) can indicate cardiovascular risk, with higher levels suggesting more severe inflammation
- CRP testing is most valuable when combined with other cardiac markers like troponin and clinical assessment
- Normal CRP levels are generally below 3 mg/L, with levels between 3-10 mg/L indicating moderate risk and above 10 mg/L suggesting high risk for cardiovascular events
- CRP rises within 4-6 hours of tissue injury and peaks at 48-72 hours, making it helpful for monitoring inflammatory response in conditions like myocardial infarction, pericarditis, and post-cardiac surgery However, the 2003 study published in Circulation 1 suggests that measuring hs-CRP may be useful as an independent marker for assessing likelihood of recurrent events in patients with stable coronary disease or acute coronary syndromes. In clinical practice, the use of CRP as a prognostic biomarker should be approached with caution, and its measurement should not be relied upon as the sole indicator of cardiovascular risk 1.
From the Research
CRP and Cardiac Disease
- C-reactive protein (CRP) is a marker of inflammation that is directly involved in atherogenesis, and elevated CRP levels are associated with increased cardiovascular risk 2.
- Studies have shown that CRP is associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD) 3, 4.
- High-sensitivity CRP (hs-CRP) can be a useful biomarker for indicating coronary artery disease (CAD) severity and can aid in risk stratification 4.
Effect of Atorvastatin on CRP
- Atorvastatin reduces plasma inflammatory and oxidant biomarkers, including CRP, in patients with risk of ASCVD 3.
- However, short-term treatment with high-dose atorvastatin shows no anti-inflammatory effects in normolipidemic subjects with normal CRP levels 5.
- The achieved CRP level on atorvastatin therapy does not predict cardiovascular events, either alone or in combination with LDL-C 6.
CRP as a Predictor of Cardiovascular Risk
- Baseline CRP is an independent predictor of cardiovascular risk beyond low-density lipoprotein cholesterol (LDL-C) 6.
- Elevated CRP levels are associated with increased cardiovascular risk, and CRP can be used to assess cardiovascular disease risk 2, 4.
- However, the relative statin effect in preventing cardiovascular events does not differ according to tertiles of baseline CRP 6.