Use of copeptin in the detection of myocardial ischemia

Aptamers Targeting Cardiac Biomarkers as an Analytical Tool for the Diagnostics of Cardiovascular Diseases: A Review

The detection of cardiac biomarkers is used for diagnostics, prognostics, and the risk assessment of cardiovascular diseases. The analysis of cardiac biomarkers is routinely performed with high-sensitivity immunological assays. Aptamers offer an attractive alternative to antibodies for analytical applications but, to date, are not widely practically implemented in diagnostics and medicinal research. This review summarizes the information on the most common cardiac biomarkers and the current state of aptamer research regarding these biomarkers. Aptamers as an analytical tool are well established for troponin I, troponin T, myoglobin, and C-reactive protein. For the rest of the considered cardiac biomarkers, the isolation of novel aptamers or more detailed characterization of the known aptamers are required. More attention should be addressed to the development of dual-aptamer sandwich detection assays and to the studies of aptamer sensing in alternative biological fluids. The universalization of aptamer-based biomarker detection platforms and the integration of aptamer-based sensing to clinical studies are demanded for the practical implementation of aptamers to routine diagnostics. Nevertheless, the wide usage of aptamers for the diagnostics of cardiovascular diseases is promising for the future, with respect to both point-of-care and laboratory testing.

The additive value of copeptin for early diagnosis and prognosis of acute coronary syndromes

BACKGROUND

One promising biomarker that has received substantial interest for the evaluation of suspected acute coronary syndromes (ACS) is copeptin. Therefore, our goal was to assess the additive value of copeptin for early diagnosis and prognosis of Non-ST segment acute coronary syndromes (NSTE-ACS).

METHODS

The study included ninety patients with suspected ACS. Patients with typical ischemic chest pain within six hours of symptom onset and without ST-segment elevation on electrocardiograph (ECG) were included. In addition to cardiac troponin I (cTnI), copeptin was assayed from venous blood samples obtained on admission, followed by serial troponin measurements six and twelve hours later. One year follow-up was performed for any major adverse cardiac events (MACEs) including cardiac death, re-infarction, re- hospitalization for ischemic events, heart failure, stroke and target lesion revascularization (TLR).

RESULTS

Of seventy nine patients included in the final analysis, Forty (50.6%) were diagnosed as unstable angina (UA), while thirty nine (49.4%) had a non-ST elevation myocardial infarction (NSTEMI). Copeptin level on admission was significantly higher among NSTEMI patients than those with UA. With regard to the correlation analyses, copeptin was positively correlated with each of, Global Registry of Acute Coronary Events (GRACE), Thrombolysis In Myocardial Infarction (TIMI) and synergy between percutaneous coronary intervention with taxus and cardiac surgery (SYNTAX) scores. The sensitivity and negative predictive value (NPV) of the combination of admission copeptin and cTn-I were 100% and 100%, respectively, versus 57% and 70%, respectively, with admission of cTn-I alone. The area under curve (AUC) of the combination of copeptin and cTn-I was (0.975, p < 0.001) and was significantly higher than the AUC of cTn-I alone (0.888, p < 0.001). Admission copeptin was an independent predictor for MACEs by multiple regression analysis (OR: 0.01, 95% CI: 0.0-0.8, P = 0.04). High values of copeptin had the highest rate of MACEs and coronary revascularization during one year of follow up.

CONCLUSION

The combination of copeptin and conventional troponin I aids in early rule out of NSTEMI virtually independent of chest pain onset (CPO) with high NPV in patients presenting within three hours from chest pain onset with excellent prognostic value for risk stratification and prediction of MACEs.

A Correlative Study Between IVIM-DWI Parameters and the Expression Levels of Ang-2 and TKT in Hepatocellular Carcinoma

Background

Noninvasive evaluation of the expression of angiopoietin-2 (Ang-2) and transketolase (TKT) in hepatocellular carcinoma (HCC) is of great significance for the clinical development of individualized treatment plans. However, the correlation between intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) and the expression of Ang-2 and TKT has not been reported. We sought to investigate the correlations between IVIM-DWI parameters and Ang-2 and TKT expression levels in HCCs.

Methods

Conventional non-enhanced magnetic resonance imaging (MRI) and IVIM-DWI and dynamic contrast MRI were performed for 61 patients with HCC before surgical treatment. Various IVIM-DWI parameters, such as apparent diffusion coefficient (ADC), slow apparent diffusion coefficient (D), fast apparent diffusion coefficient (D^*) and fraction of fast apparent diffusion coefficient (f), were calculated using Function-MADC software. Expression levels of Ang-2 and TKT in HCC were detected via immunohistochemical staining and classified into two grades. Independent sample t tests were used to compare differences in parameters between the two groups. The Spearman rank correlation test was used to analyze the correlations between IVIM-DWI parameters and Ang-2 and TKT expression levels in HCCs.

Results

The D^* and f values were significantly higher in the high Ang-2 group than in the low Ang-2 group; there were no obvious between-group differences in ADC and D. Ang-2 expression was positively correlated with D* and f but not with ADC and D. The ADC and D values were significantly lower in the high TKT group than in the low TKT group, whereas the between-group differences for D* and f were not significant. TKT expression was negatively correlated with ADC and D but not with D* and f.

Conclusions

IVIM-DWI can be used to evaluate Ang-2 and TKT expression in HCC.

Vasopressin inactivation: Role of insulin-regulated aminopeptidase

The physiological importance of vasopressin inactivation has long been appreciated, but the mechanisms and potential pathophysiologic roles of this process remain active subjects of research. Human Placental Leucine Aminopeptidase (P-LAP, encoded by the LNPEP gene) is an important determinant of vasopressinase activity during pregnancy and is associated with gestational diabetes insipidus and preeclampsia. Insulin-Regulated Aminopeptidase (IRAP), the rodent homologue of P-LAP, is coregulated with the insulin-responsive glucose transporter, GLUT4, in adipose and muscle cells. Recently, the Tether containing a UBX domain for GLUT4 (TUG) protein was shown to mediate the coordinated regulation of water and glucose homeostasis. TUG sequesters IRAP and GLUT4 intracellularly in the absence of insulin. Insulin and other stimuli cause the proteolytic cleavage of TUG to mobilize these proteins to the cell surface, where IRAP acts to terminate the activity of circulating vasopressin. Intriguingly, genetic variation in LNPEP is associated with the vasopressin response and mortality during sepsis, and increased copeptin, a marker of vasopressin secretion, is associated with cardiovascular and metabolic disease. We propose that in the setting of insulin resistance in muscle, increased cell-surface IRAP and accelerated vasopressin degradation cause a compensatory increase in vasopressin secretion. The increased vasopressin concentrations present at the kidneys then contribute to hypertension in the metabolic syndrome. Further analyses of metabolism and of vasopressin and copeptin may yield novel insights into a unified pathophysiologic mechanism linking insulin resistance and hypertension, and potentially other components of the metabolic syndrome, in humans.

Exercise upregulates copeptin levels which is not regulated by interleukin-1

Objective

Studies have suggested that arginine vasopressin (AVP) and its surrogate marker copeptin increase during exercise, independently of serum sodium and/or osmolality. In extreme cases, this can lead to runners-induced hyponatremia. Interleukin-1 (IL-1) increases during exercise and induces AVP in animal models. We here therefore investigate whether copeptin (a surrogate marker for AVP) increases upon exercise in young and healthy males, and whether this increase is regulated by IL-1.

Design

In a randomized, placebo-controlled, double-blind, crossover trial in 17 healthy male volunteers, the effect of the IL-1 receptor antagonist anakinra on exercise-induced copeptin was compared with placebo.

Methods

Participants exercised for one hour at 75% of VO_2max and were not allowed to drink/eat 6 hours before and during the study. Participants received either 100 mg of anakinra or placebo 1h before exercise. Blood was drawn at certain time intervals.

Results

In both groups, copeptin levels were induced by 2.5-fold upon exercise (p<0.001), from 4.5–10.6 pmol/l in the placebo, and 4.3–11.3 pmol/l in the anakinra group, (p = 0.38). One hour after exercise, copeptin levels dropped to 7.7 and 7.9 pmol/l in the placebo and anakinra group, respectively (p = 0.58). The increase of copeptin levels was not explained by sodium concentrations.

Conclusions

Exercise induces a continuous rise of plasma copeptin levels in healthy male volunteers independently of sodium levels and fluid intake. This increase is not regulated by the IL-1 pathway.

Water Intake, Water Balance, and the Elusive Daily Water Requirement

Water is essential for metabolism, substrate transport across membranes, cellular homeostasis, temperature regulation, and circulatory function. Although nutritional and physiological research teams and professional organizations have described the daily total water intakes (TWI, L/24h) and Adequate Intakes (AI) of children, women, and men, there is no widespread consensus regarding the human water requirements of different demographic groups. These requirements remain undefined because of the dynamic complexity inherent in the human water regulatory network, which involves the central nervous system and several organ systems, as well as large inter-individual differences. The present review analyzes published evidence that is relevant to these issues and presents a novel approach to assessing the daily water requirements of individuals in all sex and life-stage groups, as an alternative to AI values based on survey data. This empirical method focuses on the intensity of a specific neuroendocrine response (e.g., plasma arginine vasopressin (AVP) concentration) employed by the brain to regulate total body water volume and concentration. We consider this autonomically-controlled neuroendocrine response to be an inherent hydration biomarker and one means by which the brain maintains good health and optimal function. We also propose that this individualized method defines the elusive state of euhydration (i.e., water balance) and distinguishes it from hypohydration. Using plasma AVP concentration to analyze multiple published data sets that included both men and women, we determined that a mild neuroendocrine defense of body water commences when TWI is ˂1.8 L/24h, that 19⁻71% of adults in various countries consume less than this TWI each day, and consuming less than the 24-h water AI may influence the risk of dysfunctional metabolism and chronic diseases.

Comparison of plasma copeptin and multiple biomarkers for assessing prognosis of patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

Increased plasma copeptin concentrations are related to poor prognosis after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to assess prognostic significance of plasma copeptin detection compared with glial fibrillary astrocyte protein, myelin basic protein, S100B, phosphorylated axonal neurofilament subunit H, neuron-specific enolase, tau and ubiquitin carboxyl-terminal hydrolase L1 in aSAH.

METHODS

We detected plasma concentrations of the aforementioned biomarkers in 105 healthy controls using ELISA. Their predictive ability for symptomatic cerebral vasospasm and 6-month poor outcome (Glasgow Outcome Scale score of 1-3) were compared.

RESULTS

Plasma concentrations of the preceding biomarkers were highly correlated with World Federation of Neurological Surgeons subarachnoid hemorrhage scale (WFNS) scores as well as were significantly higher in patients with symptomatic cerebral vasospasm than in those without symptomatic cerebral vasospasm and in patients with poor outcome than in those with good outcome. In terms of area under receiver operating characteristic curve, their predictive value for symptomatic cerebral vasospasm and 6-month poor outcome was in the range of WFNS scores. Plasma copeptin concentration, but not plasma concentrations of other biomarkers, statistically significantly improved the predictive performance of WFNS scores.

CONCLUSIONS

Copeptin in plasma might have the potential to be a useful prognostic biomarker for aSAH.

Vasopressin: physiology, assessment and osmosensation

Vasopressin (AVP) plays a major role in the regulation of water and sodium homeostasis by its antidiuretic action on the kidney, mediated by V2 receptors. AVP secretion is stimulated by a rise in plasma osmolality, a decline in blood volume or stress. V1a receptors are expressed in vascular smooth muscle cells, but the role of vasopressin in blood pressure regulation is still a matter of debate. AVP may also play a role in some metabolic pathways, including gluconeogenesis, through its action on V1a receptors expressed in the liver. It is now understood that thirst and arginine vasopressin (AVP) release are regulated not only by the classical homeostatic, intero-sensory plasma osmolality negative feedback, but also by novel, extero-sensory, anticipatory signals. AVP measurement is time-consuming, and AVP level in the blood in the physiological range is often below the detection limit of the assays. Recently, an immunoassay has been developed for the measurement of copeptin, a fragment of the pre-provasopressin molecule that is easier to measure. It has been shown to be a good surrogate marker of AVP.

Use of copeptin for rapid rule-out of acute myocardial infarction

Copeptin is currently understood as a quantitative marker of endogenous stress. It rises rapidly in multiple acute disorders including acute myocardial infarction. As a single variable, it has only modest diagnostic accuracy for acute myocardial infarction. However, the use of copeptin within a dual-marker strategy together with conventional cardiac troponin increases the diagnostic accuracy and particularly the negative predictive value of cardiac troponin alone for acute myocardial infarction. The rapid rule-out of acute myocardial infarction is the only application in acute cardiac care mature enough to merit consideration for routine clinical care. However, the dual-marker approach seems to provide only very small incremental value when used in combination with sensitive or high-sensitivity cardiac troponin assays. This review aims to update and educate regarding the potential and the procedural details, as well as the caveats and challenges of using copeptin in clinical practice.

Comparison of the performances of copeptin and multiple biomarkers in long-term prognosis of severe traumatic brain injury

Enhanced blood levels of copeptin correlate with poor clinical outcomes after acute critical illness. This study aimed to compare the prognostic performances of plasma concentrations of copeptin and other biomarkers like myelin basic protein, glial fibrillary astrocyte protein, S100B, neuron-specific enolase, phosphorylated axonal neurofilament subunit H, Tau and ubiquitin carboxyl-terminal hydrolase L1 in severe traumatic brain injury. We recruited 102 healthy controls and 102 acute patients with severe traumatic brain injury. Plasma concentrations of these biomarkers were determined using enzyme-linked immunosorbent assay. Their prognostic predictive performances of 6-month mortality and unfavorable outcome (Glasgow Outcome Scale score of 1-3) were compared. Plasma concentrations of these biomarkers were statistically significantly higher in all patients than in healthy controls, in non-survivors than in survivors and in patients with unfavorable outcome than with favorable outcome. Areas under receiver operating characteristic curves of plasma concentrations of these biomarkers were similar to those of Glasgow Coma Scale score for prognostic prediction. Except plasma copeptin concentration, other biomarkers concentrations in plasma did not statistically significantly improve prognostic predictive value of Glasgow Coma Scale score. Copeptin levels may be a useful tool to predict long-term clinical outcomes after severe traumatic brain injury and have a potential to assist clinicians.

B-type natriuretic peptide and clinical judgment in the detection of exercise-induced myocardial ischemia

BACKGROUND

Myocardial ischemia has been shown to be associated with increased levels of B-type natriuretic peptide (BNP). However, it remains unclear whether and how BNP levels could be used clinically in patients with suspected exercise-induced myocardial ischemia.

METHODS

We enrolled 274 consecutive patients with suspected exercise-induced myocardial ischemia referred for evaluation by rest/bicycle myocardial perfusion single-photon emission computed tomography (SPECT). All clinical information available to the treating cardiologist was used to quantify the clinical judgment regarding the presence of myocardial ischemia using a visual analogue scale twice: once before and once after bicycle exercise stress testing. BNP measurements were obtained before, immediately after, and 2 hours after stress testing in a blinded manner. The presence of myocardial ischemia was adjudicated on the basis of perfusion SPECT combined with coronary angiography findings.

RESULTS

Exercise-induced myocardial ischemia was adjudicated to be present in 103 patients (38%). BNP levels were significantly higher at all time points in patients with myocardial ischemia compared with those without (P < .01 for all). The accuracy of BNP levels as quantified by the area under the receiver operating characteristic curve (AUC) was similar among the time points evaluated (AUC, 0.677-0.697). Combining clinical judgment before exercise testing with BNP levels at rest increased diagnostic accuracy from AUC 0.708 to 0.754 (P = .018). When combining clinical judgment after exercise testing with BNP levels, AUC increased from 0.741 to 0.771 (P = .055).

CONCLUSIONS

Combining clinical judgment with BNP levels increased the diagnostic accuracy regarding the presence of myocardial ischemia.

Diagnostic accuracy of combined cardiac troponin and copeptin assessment for early rule-out of myocardial infarction: a systematic review and meta-analysis

AIMS

This systematic review aimed to investigate the diagnostic accuracy of combined cardiac troponin (cTn) and copeptin assessment in comparison to cTn alone for early rule-out of acute myocardial infarction (AMI).

METHODS

Primary studies were eligible if they evaluated diagnostic accuracy for cTn with and without copeptin in patients with symptoms suggestive of AMI. AMI was defined according to the universal definition, using detection of cTn as a marker for myocardial necrosis. Eligible studies were identified by searching electronic databases (Medline, EMBASE, Science Citation Index Expanded, CINAHL, Pascal, and Cochrane) from inception to March 2013, reviewing conference proceedings and contacting field experts and the copeptin manufacturer.

RESULTS

In 15 studies totalling 8740 patients (prevalence of AMI 16%), adding copeptin improved the sensitivity of cTn assays (from 0.87 to 0.96, p=0.003) at the expense of lower specificity (from 0.84 to 0.56, p<0.001). In 12 studies providing data for 6988 patients without ST-segment elevation, the summary sensitivity and specificity estimates were 0.95 (95% CI 0.89 to 0.98) and 0.57 (95% CI 0.49 to 0.65) for the combined assessment of cTn and copeptin. When a high-sensitivity cTnT assay was used in combination with copeptin, the summary sensitivity and specificity estimates were 0.98 (95% CI 0.96 to 1.00) and 0.50 (95% CI 0.42 to 0.58).

CONCLUSION

Despite substantial between-study heterogeneity, this meta-analysis demonstrates that copeptin significantly improves baseline cTn sensitivity. Management studies are needed to establish the effectiveness and safety of measuring copeptin in combination with high-sensitivity cTnT for early rule-out of AMI without serial testing.

Plasma copeptin levels are inversely associated with intima-media-thickness in men: the population-based KORA F4 study

Background

Elevated plasma preprovasopressin (copeptin) levels are associated with cardiovascular complications as well as with an increased risk for type 2 diabetes (T2D). Here, we studied, whether plasma copeptin is related to carotid intima-media thickness (IMT), a measure of early atherosclerosis, and may thus be one explanation for the high cardiovascular risk in T2D.

Methods

Plasma concentrations of copeptin and IMT of the common carotid artery were determined in 1275 participants of the population-based KORA F4 study. We used linear regression models to investigate associations between copeptin levels and IMT.

Results

In the whole study group, copeptin levels were not significantly associated with IMT after adjustment for age and sex. Copeptin and IMT were significantly inversely associated after multivariable adjustment in the total cohort (β = -0.020 mm, 95% CI: -0.037 mm; -0.003 mm), in men (β = -0.035 mm, 95% CI: -0.061 mm; -0.009 mm) and in study participants with prediabetes (β = -0.041 mm, 95% CI: -0.078 mm; -0.005 mm) comparing quartile 4 vs quartile 1. The negative association of copeptin and IMT in men was present after adjustment for age alone. In women and patients with T2D, copeptin was not significantly associated with IMT.

Conclusions

Plasma copeptin was not associated with an increased IMT in our study cohort. In contrast, copeptin levels were related to a lower IMT in men and subjects with prediabetes, suggesting that elevated copeptin concentrations do not exert proatherogenic effects on carotid arteries.

Copeptin: a new marker in cardiology

Copeptin, the C-terminal part of the prohormone of vasopressin (AVP), is released together with AVP in stoichiometric concentrations reflecting an individual's stress level. Copeptin has come to be regarded as an important marker for identifying high-risk patients and predicting outcomes in a variety of diseases. It improves the clinical value of commonly used biomarkers and the tools of risk stratification. Elevated AVP activation and higher copeptin concentrations have been previously described in acute systemic disorders. However, the field that could benefit the most from the introduction of copeptin measurements into practice is that of cardiovascular disease. Determination of copeptin level emerges as a fast and reliable method for differential diagnosis, especially in acute coronary syndromes. A particular role in the diagnosis of acute myocardial infarction (AMI) is attributed to the combination of copeptin and troponin. According to available sources, such a combination allows AMI to be ruled out with very high sensitivity and negative predictive value. Moreover, elevated copeptin levels correlate with a worse prognosis and a higher risk of adverse events after AMI, especially in patients who develop heart failure. Some authors suggest that copeptin might be valuable in defining the moment of the introduction of treatment and its monitoring in high-risk patients. The introduction of copeptin into clinical practice might also provide a benefit on a larger scale by suggesting changes in the allocation of financial resources within the health system. Although very promising, further larger trials are required in order to assess the clinical benefits of copeptin in everyday practice and patient care.

Prevalence, extent, and independent predictors of silent myocardial infarction

BACKGROUND

The phenomenon of silent myocardial infarction is poorly understood.

METHODS

We aimed to evaluate the prevalence, extent, and independent predictors of silent myocardial infarction in 2 large independent cohorts of consecutive patients without a history of myocardial infarction referred for rest/stress myocardial perfusion single photon emission computed tomography. There were 1621 patients enrolled in the derivation cohort and 338 patients in the validation cohort. Silent myocardial infarction was diagnosed in patients with a myocardial scar ≥5% of the left ventricle.

RESULTS

In the derivation cohort, the prevalence of silent myocardial infarction was 23.3% (n = 377). The median infarct size was 10% (interquartile range [IQR] 5%-15%) of the left ventricle. The prevalence of silent myocardial infarction was 28.5% in diabetics and 21.5% in nondiabetics (P = .004). Diabetes mellitus was an independent predictor for the presence of silent myocardial infarction (odds ratio 1.5; 95% confidence interval, 1.1-1.9; P = .004). These findings were confirmed in the independent validation cohort. In the validation cohort, the prevalence of silent myocardial infarction was 26.3% (n = 89), while the prevalence was higher in diabetics (35.8%) than in nondiabetics (24%; P = .049). The median infarct size was 11.8% (IQR 5.9%-17.6%) of the left ventricle. Again, in logistic regression analysis, diabetes mellitus was a significant predictor of the presence of silent myocardial infarction.

CONCLUSION

Silent myocardial infarctions are more common than previously thought. One of 4 patients with suspected coronary artery disease had experienced a silent myocardial infarction; the extent in average is 10% of the left ventricle, and it is more common in diabetics.

Cardiac biomarkers in acute myocardial infarction

Each year, a large number of patients are seen in the Emergency Department with presentations necessitating investigation for possible acute myocardial infarction. Patients can be stratified by symptoms, risk factors and electrocardiogram results but cardiac biomarkers also have a prime role both diagnostically and prognostically. This review summarizes both the history of cardiac biomarkers as well as currently available (established and novel) assays. Cardiac troponin, our current "gold standard" biomarker criterion for the diagnosis of myocardial infarction has high sensitivity and specificity for this diagnosis and therapies instituted in patients with elevated troponin have been shown to influence outcomes. Other markers of myocardial necrosis, inflammation and neurohormonal activity have also been shown to have either diagnostic or prognostic utility, but none have been shown to be superior to troponin. The measurement of multiple biomarkers and the use of point of care markers may accelerate current diagnostic protocols for the assessment of such patients.

Copeptin as a prognostic factor for major adverse cardiovascular events in patients with coronary artery disease

BACKGROUND

C-terminal portion of provasopressin (copeptin) has recently been discussed as a novel biomarker for the early rule-out of acute myocardial infarction (AMI). The aim is to investigate the prognostic value of copeptin with regard to mortality and morbidity in patients with symptomatic coronary artery disease (CAD).

METHODS

We consecutively recruited a cath lab cohort of 2,700 patients (74.1% male; AMI, n=1316; stable angina pectoris, n=1384) presenting to the emergency department of a large primary care hospital. All patients received coronary angiography. Copeptin and other laboratory markers were sampled at the time of presentation or in the cath lab. Clinical outcomes were assessed by hospital chart analysis and telephone interviews. 2621 patients (97.1%) have been successfully followed-up at three months. The primary endpoint was a combined endpoint of rehospitalization for cardiovascular events, stroke, and all-cause death.

RESULTS

Using receiver operating characteristic curves, we calculated areas under the curve of 0.703 (95%confidence interval(CI):0.681-0.725) for the composite endpoint after three months (myocardial reinfarction, stroke, all-cause death;n=183), and 0.770 (95%CI:0.736-0.803) for all-cause death (n=76) for copeptin. A cutoff value of 21.6 pmol/L for the composite endpoint yielded a sensitivity of 56.3% and a specificity of 78.6%. The predictive performance of copeptin was independent of other clinical variables or cardiovascular risk factors, and superior to that of troponin I or other cardiac biomarkers (all:P<0.0001).

CONCLUSIONS

Copeptin may help in the prediction of major adverse cardiovascular events in patients with symptomatic CAD. Further studies should substantiate the findings and support the suggested cutoff value of the present study.

Comparison of the temporal release pattern of copeptin with conventional biomarkers in acute myocardial infarction

Background

Early detection of acute myocardial infarction (AMI) using cardiac biomarkers of myocardial necrosis remains limited since these biomarkers do not rise within the first hours from onset of AMI. We aimed to compare the temporal release pattern of the C-terminal portion of provasopressin (copeptin) with conventional cardiac biomarkers, including creatine kinase isoenzyme (CK-MB), cardiac troponin T (cTnT), and high-sensitivity cTnT (hs-cTnT), in patients with ST-elevation AMI.

Methods

We included 145 patients undergoing successful primary percutaneous coronary intervention (PCI) for a first ST-elevation AMI presenting within 12 h of symptom onset. Blood samples were taken on admission and at four time points within the first 24 h after PCI.

Results

In contrast to all other markers, copeptin levels were already elevated on admission and were higher with a shorter time from symptom onset to reperfusion and lower systolic blood pressure. Copeptin levels peaked immediately after symptom onset at a maximum of 249 pmol/L and normalized within 10 h. In contrast, CK-MB, cTnT, and hs-cTnT peaked after 14 h from symptom onset at a maximum of 275 U/L, 5.75 μg/L, and 4.16 μg/L, respectively, and decreased more gradually.

Conclusions

Copeptin has a distinct release pattern in patients with ST-elevation AMI, peaking within the first hour after symptom onset before conventional cardiac biomarkers and falling to normal ranges within the first day. Further studies are required to determine the exact role of copeptin in AMI suspects presenting within the first hours after symptom onset.

Copeptin levels associate with cardiovascular events in patients with ESRD and type 2 diabetes mellitus

In ESRD, the neurohormone arginine vasopressin (AVP) may act primarily through V1a and V1b receptors, which promote vasoconstriction, myocardial hypertrophy, and release of adrenocorticotropic hormone. The preanalytical instability of AVP limits the investigation of whether this hormone associates with cardiovascular events, but the stable glycopeptide copeptin may serve as a surrogate because it is co-secreted with AVP from the posterior pituitary. Here, we studied whether copeptin predicts cardiovascular risk and mortality in ESRD. We measured copeptin at baseline in 1241 hemodialysis patients with type 2 diabetes participating in the German Diabetes and Dialysis Study. The median copeptin level was 81 pmol/L (interquartile range, 81 to 122 pmol/L). In Cox regression analyses, compared with patients with copeptin levels in the lowest quartile (≤51 pmol/L), patients with copeptin levels in the highest quartile (>122 pmol/L) had a 3.5-fold increased risk for stroke (HR, 3.48; 95% CI: 1.71 to 7.09), a 73% higher risk for sudden death (HR, 1.73; 95% CI: 1.01 to 2.95), a 42% higher risk for combined cardiovascular events (HR, 1.42; 95% CI: 1.06 to 1.90), and a 48% higher risk for all-cause mortality (HR, 1.48; 95% CI: 1.15 to 1.90). In contrast, we did not detect significant associations between copeptin levels and risks for myocardial infarction or death caused by congestive heart failure. In conclusion, copeptin levels strongly associate with stroke, sudden death, combined cardiovascular events, and mortality in hemodialysis patients with type 2 diabetes. Whether vasopressin receptor antagonists will improve these outcomes requires further studies.

Co-peptin: Role as a novel biomarker in clinical practice

BACKGROUND

Arginine vasopressin (AVP) is a key regulator of water balance, but its instability makes reliable measurement difficult and precludes its routine use. Co-peptin is the C-terminal part of the AVP precursor which plays an important role in the correct structural formation of the AVP precursor and its efficient proteolytic maturation. Because of its stoichiometric generation, co-peptin mirrors the release of AVP and measurement of more stable co-peptin may be an indicator of AVP levels.

METHOD

A comprehensive literature search was conducted from the websites of the National Library of Medicine (http://www.ncbl.nlm.nih.gov) and Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/). The data was assessed from books and journals that published relevant articles in this field.

RESULT

Recent and ongoing research indicates the diagnostic and prognostic roles of co-peptin in various clinical settings especially in critically ill patients.

CONCLUSION

Co-peptin levels are altered in various physiological and pathological conditions indicating its possible role as a biomarker. However, further research using co-peptin in various clinical settings will prove its cost-effectiveness and clinical usefulness.

Incremental value of copeptin for rapid rule out of acute myocardial infarction

OBJECTIVES

The purpose of this study was to examine the incremental value of copeptin for rapid rule out of acute myocardial infarction (AMI).

BACKGROUND

The rapid and reliable exclusion of AMI is a major unmet clinical need. Copeptin, the C-terminal part of the vasopressin prohormone, as a marker of acute endogenous stress may be useful in this setting.

METHODS

In 487 consecutive patients presenting to the emergency department with symptoms suggestive of AMI, we measured levels of copeptin at presentation, using a novel sandwich immunoluminometric assay in a blinded fashion. The final diagnosis was adjudicated by 2 independent cardiologists using all available data.

RESULTS

The adjudicated final diagnosis was AMI in 81 patients (17%). Copeptin levels were significantly higher in AMI patients compared with those in patients having other diagnoses (median 20.8 pmol/l vs. 6.0 pmol/l, p < 0.001). The combination of troponin T and copeptin at initial presentation resulted in an area under the receiver-operating characteristic curve of 0.97 (95% confidence interval: 0.95 to 0.98), which was significantly higher than the 0.86 (95% confidence interval: 0.80 to 0.92) for troponin T alone (p < 0.001). A copeptin level <14 pmol/l in combination with a troponin T < or =0.01 microg/l correctly ruled out AMI with a sensitivity of 98.8% and a negative predictive value of 99.7%.

CONCLUSIONS

The additional use of copeptin seems to allow a rapid and reliable rule out of AMI already at presentation and may thereby obviate the need for prolonged monitoring and serial blood sampling in the majority of patients. (Advantageous Predictors of Acute Coronary Syndromes Evaluation [APACE]; NCT00470587).

C-terminal provasopressin (copeptin) is a strong prognostic marker in patients with heart failure after an acute myocardial infarction: results from the OPTIMAAL study

AIMS

The aim of the present study was to compare the prognostic value of a novel and promising marker, copeptin, with B-type natriuretic peptide (BNP), and N-terminal pro-BNP (NT-proBNP), on death or a composite cardiovascular endpoint in patients who developed heart failure after an acute myocardial infarction (AMI).

METHODS AND RESULTS

From a subset of 224 patients of the OPTIMAAL study, blood samples were drawn at a mean of 3 days after AMI when all patients had signs and/or symptoms of heart failure or a left ventricular ejection fraction <0.35. Endpoints of interest were mortality (primary endpoint of OPTIMAAL) and a composite cardiovascular endpoint, including death, MI, stroke, and/or resuscitated cardiac arrest. Mean age was 67 +/- 10 years, and mean follow-up was 33 +/- 7 months. Using univariable Cox proportional hazards survival analysis, higher levels of copeptin, BNP, and NT-proBNP were all significantly related to both mortality and the composite cardiovascular endpoint (all P < 0.01). In a multivariable Cox proportional hazards model, including all three biomarkers and other relevant covariates, a doubling of copeptin was related to a 1.83 (1.26-2.64) times increased risk of mortality (P < 0.0001) and a 1.35 (1.05-1.72) times increased risk of the composite cardiovascular endpoint (P = 0.018). Receiver operating characteristic curves indicated that copeptin [area under curve (AUC) 0.81] was a stronger predictor of mortality compared with both BNP (AUC 0.66; P = 0.0063 vs. copeptin) and NT-proBNP (AUC 0.67; P = 0.0016 vs. copeptin). Finally, changes of copeptin levels after 1 month significantly added prognostic information to the baseline value.

CONCLUSION

Copeptin is a strong and novel marker for mortality and morbidity in patients with heart failure after AMI. In this population, the predictive value of copeptin was even stronger than BNP and NT-proBNP.