ST2: Your questions answered
We have compiled a selection of our most frequently asked questions.
Q: What Is ST2?
A: ST2 is expressed by the heart in response to disease or injury. Unlike many other cardiac biomarkers, ST2 levels change quickly in response to changes in the patient’s condition—thus helping physicians make informed decisions on an appropriate course of action to take and, if needed, to quickly adjust treatment. Critical Diagnostic’s Presage ST2 Assay is a simple blood test that aids in risk assessment of heart failure patients.
Q: I understand that there is a standard cutpoint of 35 ng/ml. If my patient is above or below that cutpoint, what does that tell me?
A: By way of reference, the median normal concentration for ST2 is 18 ng/ml, while concentrations greater than 35 ng/ml are strongly indicative of increased risk of hospitalization or death. Likewise, patients with ST2 levels below the cutpoint are showing improvement and therefore at decreased risk for hospitalization or death..
Q: What clinical studies have been done on ST2?
A: Numerous published studies involving tens of thousands of subjects have demonstrated that the level of ST2 in blood can best predict patient outcomes.
Q: Natriuretic peptides, such as BNP and NTproBNP, are established biomarkers for heart failure. Please explain the additional clinical benefit of ST2?
A: ST2 and natriuretic peptides (NPs) are measures of separate and distinct biological processes. As markers of hemodynamic instability or myocyte stretch NPs are more suitable for diagnosis, however with 25% of patients being rehospitalized within 30 days of discharge, their power for prognosis is insufficient. Study after study has shown that ST2, as a biomarker of disease progression and fibrosis, is the most powerful and clinically useful biomarker for prognosis.
Q: Is ST2 affected by any confounding factors, like the natriuretic peptides are?
A. While NPs have confounding factors that influence levels, including age, gender, high BMI, and impaired renal function. ST2 exhibits none of those confounders, and is thus quite helpful in those grey areas.
Q: What if the NP I’m using is positive, but the ST2 is negative, and vice versa?
A: ST2 and NPs reflect two distinct but overlapping biological pathways, therefore they provide independent and complementary feedback on the disease. As studies have shown, in the case where either NP or ST2 are elevated, it likely that the patient is progressing towards a worsening condition, therefore standard of care coupled with more aggressive treatment may be indicated. We should also add that when the NP and ST2 levels are both low, it’s a strong signal that the patient is improving, and where both are high, the patient is at significant risk for worsening condition or death.
Q: Describe the relationship between ST2 and Galectin-3?
A: Importantly, ST2 gives an early signal for short-term events, functioning as a trigger for initial fibrosis and the cascade of events leading to cardiac remodeling. From published data Galectin-3, on the other hand, is an intrinsic mediator of fibrosis and cardiac remodeling and is thought to reflect a later stage of the disease process. In clinical studies where both biomarkers were tested, ST2 had twice the predictive value of Galectin-3.
Q: How often should a heart failure patient be tested for ST2?
A: There is currently no guideline for frequency of testing. It depends on the severity of the patient’s HF status. We recommend that a HF patient should be tested every time they come in for an outpatient visit, and more often if a patient is in advanced stages of heart failure or hospitalized.
Q: There’s a lot of talk lately about the high rates of rehospitalization of heart failure patients. What role can ST2 play in lowering these readmissions?
A: Of the over one million Europeans that end up in hospital for heart failure each year, an alarming one in four will be re-admitted within 30 days of discharge. The Presage ST2 Assay from Critical Diagnostics, allows accurate prognosis and risk stratification of these patients, which, in turn, provides an essential element to disease management programs that provides physicians with a means of selecting those who are identified as requiring focused care. Using ST2 as part of a patient management program can reduce 30-day rehospitalization rates by 17.3% and also reduce 30-day mortality rates by 17.6%. A copy of a white paper report on reducing hospital readmissions using ST2 is available here.
A: ST2 is expressed by the heart in response to disease or injury. Unlike many other cardiac biomarkers, ST2 levels change quickly in response to changes in the patient’s condition—thus helping physicians make informed decisions on an appropriate course of action to take and, if needed, to quickly adjust treatment. Critical Diagnostic’s Presage ST2 Assay is a simple blood test that aids in risk assessment of heart failure patients.
Q: I understand that there is a standard cutpoint of 35 ng/ml. If my patient is above or below that cutpoint, what does that tell me?
A: By way of reference, the median normal concentration for ST2 is 18 ng/ml, while concentrations greater than 35 ng/ml are strongly indicative of increased risk of hospitalization or death. Likewise, patients with ST2 levels below the cutpoint are showing improvement and therefore at decreased risk for hospitalization or death..
Q: What clinical studies have been done on ST2?
A: Numerous published studies involving tens of thousands of subjects have demonstrated that the level of ST2 in blood can best predict patient outcomes.
Q: Natriuretic peptides, such as BNP and NTproBNP, are established biomarkers for heart failure. Please explain the additional clinical benefit of ST2?
A: ST2 and natriuretic peptides (NPs) are measures of separate and distinct biological processes. As markers of hemodynamic instability or myocyte stretch NPs are more suitable for diagnosis, however with 25% of patients being rehospitalized within 30 days of discharge, their power for prognosis is insufficient. Study after study has shown that ST2, as a biomarker of disease progression and fibrosis, is the most powerful and clinically useful biomarker for prognosis.
Q: Is ST2 affected by any confounding factors, like the natriuretic peptides are?
A. While NPs have confounding factors that influence levels, including age, gender, high BMI, and impaired renal function. ST2 exhibits none of those confounders, and is thus quite helpful in those grey areas.
Q: What if the NP I’m using is positive, but the ST2 is negative, and vice versa?
A: ST2 and NPs reflect two distinct but overlapping biological pathways, therefore they provide independent and complementary feedback on the disease. As studies have shown, in the case where either NP or ST2 are elevated, it likely that the patient is progressing towards a worsening condition, therefore standard of care coupled with more aggressive treatment may be indicated. We should also add that when the NP and ST2 levels are both low, it’s a strong signal that the patient is improving, and where both are high, the patient is at significant risk for worsening condition or death.
Q: Describe the relationship between ST2 and Galectin-3?
A: Importantly, ST2 gives an early signal for short-term events, functioning as a trigger for initial fibrosis and the cascade of events leading to cardiac remodeling. From published data Galectin-3, on the other hand, is an intrinsic mediator of fibrosis and cardiac remodeling and is thought to reflect a later stage of the disease process. In clinical studies where both biomarkers were tested, ST2 had twice the predictive value of Galectin-3.
Q: How often should a heart failure patient be tested for ST2?
A: There is currently no guideline for frequency of testing. It depends on the severity of the patient’s HF status. We recommend that a HF patient should be tested every time they come in for an outpatient visit, and more often if a patient is in advanced stages of heart failure or hospitalized.
Q: There’s a lot of talk lately about the high rates of rehospitalization of heart failure patients. What role can ST2 play in lowering these readmissions?
A: Of the over one million Europeans that end up in hospital for heart failure each year, an alarming one in four will be re-admitted within 30 days of discharge. The Presage ST2 Assay from Critical Diagnostics, allows accurate prognosis and risk stratification of these patients, which, in turn, provides an essential element to disease management programs that provides physicians with a means of selecting those who are identified as requiring focused care. Using ST2 as part of a patient management program can reduce 30-day rehospitalization rates by 17.3% and also reduce 30-day mortality rates by 17.6%. A copy of a white paper report on reducing hospital readmissions using ST2 is available here.