High Sensitivity C-Reactive Protein (hsCRP) Assay

CRP Test

The high-sensitivity C-reactive protein (hsCRP) assay is a quantitative analysis test of very low levels of C-reactive protein (CRP) in the blood. The hsCRP assay is being increasingly used as a marker for cardiac risk assessment and as a prognostic tool in heart disease. The CRP test, in addition to lipid evaluation and global risk scoring systems, helps in the evaluation of cardiovascular disease risk in an individual.

C-reactive protein is an acute phase protein that appears in circulation in response to inflammatory cytokines, such as interleukin-6, and serves as a biomarker for systemic inflammation.1

Following a systematic review of the association between inflammatory markers and coronary heart disease and stroke, the American Heart Association (AHA) and Centers for Disease Control and Prevention (CDC) developed a scientific statement that recommends hsCRP as a more sensitive assay for the prediction of vascular disease, compared to traditional assays for circulating C-reactive protein levels. 2,3

The AHA/CDC Scientific Statement Summary2,3

hsCRP is a global indicator of future vascular events in adults without any previous history of cardiovascular disease (CVD), with acceptable precision levels down to or below 0.3 mg/L

  • hsCRP enhances risk assessment and therapeutic outcomes in primary CVD prevention
  • hsCRP is particularly advantageous for assessing the risk in patients with
    • Framingham 10-year risk scores of 10%-20% and/or
    • LDL levels of <160 mg/dL
  • hsCRP acts as an independent marker for evaluating the possibility of recurrent cardiac events, such as myocardial infarction or restenosis, after percutaneous coronary intervention

Clinical Applications

hsCRP in Atherosclerosis and Plaque Instability/Inflammation

With the recognition of the crucial link between arterial damage, inflammatory processes, and coronary atherosclerosis, hsCRP estimation has assumed a vital role in cardiac risk assessment. C-reactive protein is an important pathogenic factor for atherosclerosis and induces several reactions involved in atherothrombogenesis:

  • Activates complement and attacks monocytes
  • Incites endothelial dysfunction
  • Augments a procoagulant state
  • Contributes to plaque instability/rupture

hsCRP in Risk Stratification and Risk Assessment

hsCRP levels help in cardiac risk stratification and assessment, and it are a key prognostic factor in conditions such as:3

  • Acute coronary syndrome (ACS)
  • Stroke
  • Peripheral artery disease (PAD)
  • Post-MI complications such as cardiac failure4

Multiple decision limits

Risk Stratification: hsCRP is used to determine the probability of recurrence of cardiac events in patients with stable coronary heart disease and ACS.

Risk Assessment: The hsCRP assay has been recommended in patients with intermediate risk of coronary heart disease (CHD) in order to determine the need for further evaluation and therapy.

Low risk

<1 mg/L

Average risk

1-3 mg/L

High risk

>3 mg/L

Capture trial

hsCRP in Arterial Restenosis

In patients undergoing percutaneous coronary interventions, hsCRP is a predictor of early complications and late clinical stenosis and mortality.

hsCRP in the Acute Phase of Coronary Events

hsCRP adds prognostic value as an acute phase marker for cardiac risk:

  • Predicts the prognosis in ACS, stable angina, unstable angina (UA) and acute myocardial infarction (AMI)
  • Adds independent and additive prognostic value to troponin
  • Provides additional prognostic value in patients with negative cardiac troponin results

hsCRP in Predicting Future Cardiac Events

hsCRP is a global predictor of future vascular events in adults without known CVD.

Sensitivity for Cardiovascular Applications
Traditional CRP tests cannot detect the low levels of inflammation associated with an increased risk of CVD. Only hsCRP assays can detect these small elevations.

Reliable Answers to Critical Cardiac Questions
Siemens Healthcare Diagnostics was the first company to offer a high-sensitivity C-reactive protein (hsCRP) assay with a cardiac-specific claim. Siemens offers more solutions for cardiac-specific hsCRP testing across multiple instrument platforms.

Learn more about our complete menu of cardiac biomarkers


  1. American Heart Association. Inflammation, Heart Disease and Stroke. http://www.americanheart.org/presenter.jhtml?identifier=4648. Accessed December 2008.
  2. Pearson TA, et al. Circulation. 2003;107:499-511. http://circ.ahajournals.org/cgi/content/full/107/3/499
  3. Ridker PM. Circulation. 2003;107:363-369. http://circ.ahajournals.org/cgi/content/full/107/3/363
  4. Dedobbeleer C, et al. Acta Cardiol. 2004;59(3):291-296. http://www.ncbi.nlm.nih.gov/pubmed/15255461?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_Disco veryPanel.Pubmed_Discovery_RA&linkpos=1&log$=relatedarticles&logdbfrom=pubmed
  5. Heeschen C, et al. J Am Coll Cardiol. 2000;35:1535-42. http://www.ncbi.nlm.nih.gov/pubmed/10807457?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_Disco veryPanel.Pubmed_Discovery_RA&linkpos=2&log$=relatedarticles&logdbfrom=pubmed