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Test ID ST2S ST2, Serum

Reporting Name

ST2, S

Useful For

Aiding in prognosis for patients diagnosed with chronic heart failure

Specimen Type

Serum Red

Specimen Required

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.

Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Frozen (preferred) 90 days
  Refrigerated  7 days
  Ambient  72 hours

Reference Values


<24 months: not established

2-17 years: ≤43.0 ng/mL

≥18 years: ≤ 52.0 ng/mL



<24 months: not established

2-17 years: ≤43.0 ng/mL

≥18 years: ≤38.7 ng/mL

Day(s) and Time(s) Performed

Tuesday; 8 a.m.

Test Classification

This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
ST2S ST2, S 90239-5


Result ID Test Result Name Result LOINC Value
61723 ST2, S 90239-5

Clinical Information

Heart failure is a chronic, progressive, complex cardiovascular disorder with a variety of etiologies and heterogeneity with respect to the clinical presentation of the patient. Heart failure is significantly increasing in prevalence with an aging population and is associated with high short- and long-term mortality rate. Over 80% of patients diagnosed and treated for acute heart failure syndromes in the emergency department are readmitted within the forthcoming year, incurring costly treatments and therapies.(1)


The development and progression of heart failure is a clinically silent process until manifestation of the disorder, which typically occurs late and irreversibly into its progression. Mechanistically heart failure, whether due to systolic or diastolic dysfunction, is thought to progress primarily through adverse cardiac remodeling and fibrosis in response to cardiac injury or stress.(2) Soluble ST2 (sST2) is a biomarker that appears to be actively involved with interleukin (IL)-33 in modulating cardiac remodeling and ventricular function via effects in the inflammatory and apoptosis pathways.(3)


ST2 is a member of the IL-1 receptor family and has 2 isoforms that are directly implicated in progression of cardiac disease: soluble ST2 (sST2) and a transmembrane-bound form, ST2 ligand (ST2L). IL-33 is the hormone that interacts with ST2L, protecting against left ventricular hypertrophy and myocardial fibrosis to effectively preserve cardiac function. Therefore, when sST2 concentrations are high, IL-33 is unavailable for cardioprotective signaling, leaving the heart vulnerable to the effects of sST2. High concentrations of sST2 result in cellular death, tissue fibrosis, reduced cardiac function, and an increase in the rate of disease progression.


Clinically, ST2 concentrations in the HF-ACTION heart failure study were a significant predictor of mortality, all-cause hospitalization, mortality due to cardiovascular disease, and hospitalization due to cardiovascular disease using a cutpoint of 35 ng/mL. In addition, mortality risk was significantly higher in patients with ST2 greater than 35 ng/mL.(4) The risk appears early and persists throughout the follow-up period.


Clinical risk categories are substantiated by results from several large chronic heart failure studies:

-Low risk: ≤35.0 ng/mL

-High risk: >35.0 ng/mL (high risk)


Results should be interpreted in the context of the individual patient presentation. Elevated ST2 results indicate an increased risk for adverse outcomes and signal the adverse remodeling and progression of disease.


The reference interval was derived from normal donors without a history of cardiovascular disease, stroke, diabetes, renal disease, liver disease, or autoimmune diseases. The reference range is gender dependent; however, it is the clinical cutpoint that is recognized as providing the most utility.


Knowledge of ST2 results in a heart failure patient may assist in cardiovascular risk stratification and lead to more aggressive management. There are no specific ST2 inhibitors available at this time and heart failure patients with elevated ST2 concentrations should be treated and monitored according to established guidelines. Angiotensin receptor blockers (ARBs) and aldosterone antagonists are thought to be particularly effective.

Clinical Reference

1. Weintraub NL, Collins SP, Pang PS, et al: Acute heart failure syndromes: emergency department presentation, treatment, and disposition: Current approaches and future aims: a scientific statement from the American Heart Association. Circulation 2010;122:1975-1996. doi: 10.1161/CIR.0b013e3181f9a223

2. Kakkar R, Lee R: The IL-33/ST2 Pathway: therapeutic target and novel biomarker. Nat Rev Drug Discov 2008;7:827-840. doi: 10.1038/nrd2660

3. Seki K, Sanada S, Kudinova AY, et al: Interleukin-33 prevents apoptosis and improves survival after experimental myocardial infarction through ST2 signaling. Circ Heart Fail 2009;2(6):684-691. doi: 10.1161/CIRCHEARTFAILURE.109.873240

4. Whellan DJ, O'Connor CM, Lee, KL, et al: HF-ACTION Trial Investigators. Heart failure and a controlled trial investigating outcomes of exercise training (HF-ACTION): design and rationale. Am Heart J 2007;153(2):201-211

5. Dieplinger B, Januzzi J, Steinmair M, et al: Analytical and clinical evaluation of a novel high-sensitivity assay for measurement of soluble ST2 in human plasma - The Presage ST2 Assay. Clin Chim Acta 2009;409:33-40. doi: 10.1016/j.cca.2009.08.010

6. Meeusen JW, Johnson JN, Gray A, et al: Soluble ST2 and galectin-3 in pediatric patients without heart failure. Clin Biochem 2015;Dec;48(18):1337-1340. doi: 10.1016/j.clinbiochem.2015.08.007

Analytic Time

1 day

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)


If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.