Prognostic performance of serial in-hospital measurements of copeptin and multiple novel biomarkers among patients with worsening heart failure: results from the MOLITOR study

Copeptin as a surrogate marker for arginine vasopressin: analytical insights, current utility, and emerging applications

Copeptin is a 39-amino-acid long glycosylated peptide with a leucine-rich core segment in the C-terminal part of pre-pro-vasopressin. It exhibits a rapid response comparable to arginine vasopressin (AVP) in response to osmotic, hemodynamic, and nonspecific stress-related stimuli. This similarity can be attributed to equimolar production of copeptin alongside AVP. However, there are markedly different decay kinetics for both peptides, with an estimated initial half-life of copeptin being approximately two times longer than that of AVP. Like AVP, copeptin correlates strongly over a wide osmolality range in healthy individuals, making it a useful alternative to AVP measurement. While copeptin does not appear to be significantly affected by food intake, small amounts of oral fluid intake may result in a significant decrease in copeptin levels. Compared to AVP, copeptin is considerably more stable in vitro. An automated immunofluorescent assay is now available and has been used in recent landmark trials. However, separate validation studies are required before copeptin thresholds from these studies are applied to other assays. The biological variation of copeptin in presumably healthy subjects has been recently reported, which could assist in defining analytical performance specifications for this measurand. An established diagnostic utility of copeptin is in the investigation of polyuria-polydipsia syndrome and copeptin-based testing protocols have been explored in recent years. A single baseline plasma copeptin >21.4 pmol/L differentiates AVP resistance (formerly known as nephrogenic diabetes insipidus) from other causes with 100% sensitivity and specificity, rendering water deprivation testing unnecessary in such cases. In a recent study among adult patients with polyuria-polydipsia syndrome, AVP deficiency (formerly known as central diabetes insipidus) was more accurately diagnosed with hypertonic saline-stimulated copeptin than with arginine-stimulated copeptin. Glucagon-stimulated copeptin has been proposed as a potentially safe and precise test in the investigation of polyuria-polydipsia syndrome. Furthermore, copeptin could reliably identify those with AVP deficiency among patients with severe hypernatremia, though its diagnostic utility is reportedly limited in the differential diagnosis of profound hyponatremia. Copeptin measurement may be a useful tool for early goal-directed management of post-operative AVP deficiency. Additionally, the potential prognostic utility of copeptin has been explored in other diseases. There is an interest in examining the role of the AVP system (with copeptin as a marker) in the pathogenesis of insulin resistance and diabetes mellitus. Copeptin has been found to be independently associated with an increased risk of incident stroke and cardiovascular disease mortality in men with diabetes mellitus. Increased levels of copeptin have been reported to be independently predictive of a decline in estimated glomerular filtration rate and a greater risk of new-onset chronic kidney disease. Furthermore, copeptin is associated with disease severity in patients with autosomal dominant polycystic kidney disease. Copeptin predicts the development of coronary artery disease and cardiovascular mortality in the older population. Moreover, the predictive value of copeptin was found to be comparable with that of N-terminal pro-brain natriuretic peptide for all-cause mortality in patients with heart failure. Whether the measurement of copeptin in these conditions alters clinical management remains to be demonstrated in future studies.

Biological Variation Estimates for Plasma Copeptin and Clinical Implications

BACKGROUND

Plasma copeptin measurement is useful for the differential diagnoses of polyuria-polydipsia syndrome. It has also been proposed as a prognostic marker for cardiovascular diseases. However, limited information is available about the within- (CVI) and between-subject (CVG) biological variation (BV). This study presents BV estimates for copeptin in healthy individuals.

METHODS

Samples were collected weekly from 41 healthy subjects over 5 weeks and analyzed using the BRAHMS Copeptin proAVP KRYPTOR assay after at least 8 h of food and fluid abstinence. Outlier detection, variance homogeneity, and trend analysis were performed followed by CV-ANOVA for BV and analytical variation (CVA) estimation with 95% confidence intervals. Reference change values (RCVs), index of individuality (II), and analytical performance specification (APS) were also calculated.

RESULTS

The analysis included 178 results from 20 males and 202 values from 21 females. Copeptin concentrations were significantly higher in males than in females (mean 8.5 vs 5.2 pmol/L, P < 0.0001). CVI estimates were 18.0% (95% CI, 15.4%-21.6%) and 19.0% (95% CI, 16.4%-22.6%), for males and females, respectively; RCVs were -35% (decreasing value) and 54% (increasing value). There was marked individuality for copeptin. No result exceeded the diagnostic threshold (>21.4 pmol/L) for arginine vasopressin resistance.

CONCLUSIONS

The availability of BV data allows for refined APS and associated II, and RCVs applicable as aids in the serial monitoring of patients with specific diseases such as heart failure. The BV estimates are only applicable in subjects who abstained from oral intake due to the rapid and marked effects of fluids on copeptin physiology.

Differential Associations of A-/B-Type Natriuretic Peptides With Cardiac Structure, Function, and Prognosis in Heart Failure

BACKGROUND

Natriuretic peptide (NP) elevations are prognostic in heart failure (HF), but relative atrial NP deficiency in acute HF has been suggested.

OBJECTIVES

The authors compared plasma concentrations and relative strength of associations of A- and B-type NPs with cardiac structure/function and clinical outcomes in HF.

METHODS

Midregional pro-atrial natriuretic peptide (MR-proANP), B-type natriuretic peptide (BNP), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were measured in patients with compensated HF in a prospective, multicenter study. The primary outcome was a composite of HF-hospitalization or all-cause mortality. Secondary outcomes included individual primary outcome components and cardiovascular admission.

RESULTS

Among 1,278 patients (age 60.1 ± 12.1 years, 82% men, left ventricular ejection fraction [LVEF] 34% ± 14%), median concentrations of MR-proANP were 990 pg/mL (Q1-Q3: 557-1,563 pg/mL), NT-proBNP 1,648 pg/mL (Q1-Q3: 652-3,960 pg/mL), and BNP 291 pg/mL (Q1-Q3: 103-777 pg/mL). No subpopulation with inappropriately low MR-proANP (relative to BNP/NT-proBNP) was observed. Clinical event rates were similar for biomarker tertiles. Increments in MR-proANP exhibited steeper associations with concurrent shifts in left ventricular size, diastolic indexes and LVEF than BNP/NT-proBNP at baseline and serially (P < 0.05), and lower odds of beneficial left ventricular reverse remodeling: OR: 0.35 (95% CI: 0.18-0.70). In single-biomarker models, MR-proANP(log10) was associated with the highest hazard (4 to 6 times) for each outcome. In multimarker models, independent associations were observed for the primary outcome (MR-proANP and NT-proBNP), HF-hospitalization and cardiovascular admission (MR-proANP only), and all-cause mortality (NT-proBNP only) (P < 0.05). The discriminative value of MR-proANP was superior to BNP/NT-proBNP (HF-hospitalization) and BNP (primary outcome) (P < 0.05).

CONCLUSIONS

MR-proANP was not inappropriately low relative to concurrent BNP/NT-proBNP values. Proportional increments in MR-proANP were more pronounced than for B-peptides for given decrements in cardiac structure/function. MR-proANP offered greater independent predictive power overall.

Glutamate infusion associated with reduced rises of p-Copeptin after coronary surgery: Substudy of GLUTAMICS II

BACKGROUND

Glutamate plays a key role for post-ischaemic recovery of myocardial metabolism. According to post hoc analyses of the two GLUTAMICS trials, patients without diabetes benefit from glutamate with less myocardial dysfunction after coronary artery bypass surgery (CABG). Copeptin reflects activation of the Arginine Vasopressin system and is a reliable marker of heart failure but available studies in cardiac surgery are limited. We investigated whether glutamate infusion is associated with reduced postoperative rises of plasma Copeptin (p-Copeptin) after CABG.

METHODS

A prespecified randomised double-blind substudy of GLUTAMICS II. Patients had left ventricular ejection fraction ≤0.30 or EuroSCORE II ≥3.0 and underwent CABG ± valve procedure. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h was commenced 10-20 min before the release of the aortic cross-clamp and then continued for another 150 min P-Copeptin was measured preoperatively and postoperatively on day one (POD1) and day three. The primary endpoint was an increase in p-Copeptin from the preoperative level to POD1. Postoperative stroke ≤24 h and mortality ≤30 days were safety outcomes.

RESULTS

We included 181 patients of whom 48% had diabetes. The incidence of postoperative mortality ≤30 days (0% vs. 2.1%; p = .50) and stroke ≤24 h (0% vs. 3.2%; p = .25) did not differ between the glutamate group and controls. P-Copeptin increased postoperatively with the highest values recorded on POD1 without significant inter-group differences. Among patients without diabetes, p-Copeptin did not differ preoperatively but postoperative rise from preoperative level to POD1 was significantly reduced in the glutamate group (73 ± 66 vs. 115 ± 102 pmol/L; p = .02). P-Copeptin was significantly lower in the Glutamate group on POD1 (p = .02) and POD 3 (p = .02).

CONCLUSIONS

Glutamate did not reduce rises of p-Copeptin significantly after moderate to high-risk CABG. However, glutamate was associated with reduced rises of p-Copeptin among patients without diabetes. These results agree with previous observations suggesting that glutamate mitigates myocardial dysfunction after CABG in patients without diabetes. Given the exploratory nature of these findings, they need to be confirmed in future studies.

Copeptin, Natriuretic Peptides, and Cardiovascular Outcomes in Patients With CKD: The German Chronic Kidney Disease (GCKD) Study

Rationale & Objective

Copeptin and Midrange pro-atrial natriuretic peptide (MR-pro-ANP) are associated with outcomes independently of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) in patients with heart failure (HF). The value of these markers in patients with chronic kidney disease (CKD) has not been studied.

Study Design

Prospective cohort study.

Setting & Participants

A total of 4,417 patients enrolled in the German Chronic Kidney Disease (GCKD) study with an estimated glomerular filtration rate of 30-60 mL/min/1.73m2 or overt proteinuria (urinary albumin-creatinine ratio >300mg/g or equivalent).

Exposures

Copeptin, MR-pro-ANP, and NT-pro-BNP levels were measured in baseline samples.

Outcomes

Noncardiovascular death, cardiovascular (CV) death, major adverse CV event (MACE), and hospitalization for HF.

Analytical Approach

HRs for associations of Copeptin, MR-pro-ANP, and NT-pro-BNP with outcomes were estimated using Cox regression analyses adjusted for established risk factors.

Results

During a maximum follow-up of 6.5 years, 413 non-CV deaths, 179 CV deaths, 519 MACE, and 388 hospitalizations for HF were observed. In Cox regression analyses adjusted for established risk factors, each one of the 3 markers were associated with all the 4 outcomes, albeit the highest HRs were found for NT-pro-BNP. When models were extended to include all the 3 markers, NT-pro-BNP remained associated with all 4 outcomes. Conversely, from the 2 novel markers, associations remained only for Copeptin with non-CV death (HR, 1.62; 95% CI, 1.04-2.54 for highest vs lowest quintile) and with hospitalizations for HF (HR, 1.73; 95% CI, 1.08-2.75).

Limitations

Single-point measurements of Copeptin, MR-pro-ANP, and NT-pro-BNP.

Conclusions

In patients with moderately severe CKD, we confirm NT-pro-BNP to be strongly associated with all outcomes examined. As the main finding, the novel marker Copeptin demonstrated independent associations with non-CV death and hospitalizations for HF, and should therefore be evaluated further for risk assessment in CKD.

Plain-Language Summary

A blood sample-based biomarker that indicates high cardiovascular risk in a patient with kidney disease would help to guide interventions and has the potential to improve outcomes. In 4,417 patients of the German Chronic Kidney Disease study, we assessed the relationship of Copeptin, pro-atrial natriuretic peptide, and N-terminal pro-brain natriuretic peptide (NT-pro-BNP) with important outcomes over a follow-up period of 6.5 years. NT-pro-BNP was strongly associated with all of the 4 outcomes, including death unrelated to cardiovascular disease, death because of cardiovascular disease, a major cardiovascular event, and hospitalization for heart failure. Copeptin was associated with death unrelated to cardiovascular disease and hospitalization for heart failure. NT-pro-BNP and Copeptin are, therefore, promising candidates for a blood sample-based strategy to identify patients with kidney disease at high cardiovascular risk.

Depression, anxiety, and quality of life as predictors of rehospitalization in patients with chronic heart failure

BACKGROUND

Chronic heart failure (CHF) is a severe condition, often co-occurring with depression and anxiety, that strongly affects the quality of life (QoL) in some patients. Conversely, depressive and anxiety symptoms are associated with a 2-3 fold increase in mortality risk and were shown to act independently of typical risk factors in CHF progression. The aim of this study was to examine the impact of depression, anxiety, and QoL on the occurrence of rehospitalization within one year after discharge in CHF patients.

METHODS

148 CHF patients were enrolled in a 10-center, prospective, observational study. All patients completed two questionnaires, the Hospital Anxiety and Depression Scale (HADS) and the Questionnaire Short Form Health Survey 36 (SF-36) at discharge timepoint.

RESULTS

It was found that demographic and clinical characteristics are not associated with rehospitalization. Still, the levels of depression correlated with gender (p ≤ 0.027) and marital status (p ≤ 0.001), while the anxiety values ​​were dependent on the occurrence of chronic obstructive pulmonary disease (COPD). However, levels of depression (HADS-Depression) and anxiety (HADS-Anxiety) did not correlate with the risk of rehospitalization. Univariate logistic regression analysis results showed that rehospitalized patients had significantly lower levels of Bodily pain (BP, p = 0.014), Vitality (VT, p = 0.005), Social Functioning (SF, p = 0.007), and General Health (GH, p = 0.002). In the multivariate model, poor GH (OR 0.966, p = 0.005) remained a significant risk factor for rehospitalization, and poor General Health is singled out as the most reliable prognostic parameter for rehospitalization (AUC = 0.665, P = 0.002).

CONCLUSION

Taken together, our results suggest that QoL assessment complements clinical prognostic markers to identify CHF patients at high risk for adverse events.

CLINICAL TRIAL REGISTRATION

The study is registered under http://clinicaltrials.gov (NCT01501981, first posted on 30/12/2011), sponsored by Charité - Universitätsmedizin Berlin.

Clinical Potential of Adrenomedullin Signaling in the Cardiovascular System

Numerous clinical studies have revealed the utility of circulating AM (adrenomedullin) or MR-proAM (mid-regional proAM 45-92) as an effective prognostic and diagnostic biomarker for a variety of cardiovascular-related pathophysiologies. Thus, there is strong supporting evidence encouraging the exploration of the AM-CLR (calcitonin receptor-like receptor) signaling pathway as a therapeutic target. This is further bolstered because several drugs targeting the shared CGRP (calcitonin gene-related peptide)-CLR pathway are already Food and Drug Administration-approved and on the market for the treatment of migraine. In this review, we summarize the AM-CLR signaling pathway and its modulatory mechanisms and provide an overview of the current understanding of the physiological and pathological roles of AM-CLR signaling and the yet untapped potentials of AM as a biomarker or therapeutic target in cardiac and vascular diseases and provide an outlook on the recently emerged strategies that may provide further boost to the possible clinical applications of AM signaling.

Role of Copeptin and hs-cTnT to Discriminate AHF from Uncomplicated NSTE-ACS with Baseline Elevated hs-cTnT-A Derivation and External Validation Study

BACKGROUND

In light of overlapping symptoms, discrimination between non-ST-elevation (NSTE) acute coronary syndrome (ACS) and acute heart failure (HF) is challenging, particularly in patients with equivocal clinical presentation for suspected ACS. We sought to evaluate the diagnostic and prognostic properties of copeptin in this scenario.

METHODS

Data from 1088 patients from a single-center observational registry were used to test the ability of serial high sensitivity cardiac troponin T (hs-cTnT)-compared to copeptin, or a combination of copeptin with hs-cTnT-to discriminate acute HF from uncomplicated non-ST-elevation myocardial infarction (NSTEMI) and to evaluate all-cause mortality after 365 days. Patients with STEMI, those with unstable angina and either normal or undetectable hs-cTnT concentrations were excluded. The findings were validated in an independent external NSTE-ACS cohort.

RESULTS

A total of 219 patients were included in the analysis. The final diagnosis was acute HF in 56 and NSTE-ACS in 163, with NSTEMI in 78 and unstable angina having stable elevation of hs-cTnT >ULN in 85. The rate of all-cause death at 1 year was 9.6% and occurred significantly more often in acute HF than in NSTE-ACS (15 vs. 6%, p < 0.001). In the test cohort, the area under the receiver operator curve (AUC) for the discrimination of acute HF vs. NSTE-ACS without HF was 0.725 (95% confidence interval [CI] 0.625-0.798) for copeptin and significantly higher than for hs-cTnT at 0 h (AUC = 0.460, 0.370-0.550) or at 3 h (AUC = 0.441, 0.343-0.538). Copeptin and hs-cTnT used either as continuous values or at cutoffs optimized to yield 90% specificity for acute HF were associated with significantly higher age- and sex-adjusted risk for all-cause mortality at 365 days. The findings from the test cohort were consistently replicated in the independent external NSTE-ACS validation cohort.

CONCLUSIONS

High concentrations of copeptin in patients with suspected NSTE-ACS and equivocal clinical presentation suggest the presence of acute HF compared to uncomplicated NSTE-ACS and are associated with higher rates of all-cause death at 365 days.

Advances in congestive heart failure biomarkers

Congestive heart failure (CHF) is the leading cause of morbidity and mortality in the elderly worldwide. Although many biomarkers associated with in heart failure, these are generally prognostic and identify patients with moderate and severe disease. Unfortunately, the role of biomarkers in decision making for early and advanced heart failure remains largely unexplored. Previous studies suggest the natriuretic peptides have the potential to improve the diagnosis of heart failure, but they still have significant limitations related to cut-off values. Although some promising cardiac biomarkers have emerged, comprehensive data from large cohort studies is lacking. The utility of multiple biomarkers that reflect various pathophysiologic pathways are increasingly being explored in heart failure risk stratification and to diagnose disease conditions promptly and accurately. MicroRNAs serve as mediators and/or regulators of renin-angiotensin-induced cardiac remodeling by directly targeting enzymes, receptors and signaling molecules. The role of miRNA in HF diagnosis is a promising area of research and further exploration may offer both diagnostic and prognostic applications and phenotype-specific targets. In this review, we provide insight into the classification of different biochemical and molecular markers associated with CHF, examine clinical usefulness in CHF and highlight the most clinically relevant.

Role of copeptin in diagnosis and outcome prediction in patients with heart failure: a systematic review and meta-analysis

Introduction: This systematic review and meta-analysis of 19 studies, was conducted to evaluate the role of copeptin in diagnosis and outcome prediction in HF patients. Materials and Methods: A systematic literature search for clinical trials reporting copeptin levels in HF patients was performed using EMBASE, PubMed, Cochrane Register of Controlled Trials, and Google Scholar. Articles from databases published by January 2nd, 2022, that met the selection criteria were retrieved and reviewed. The random effects model was used for analyses. Results: Pooled analysis found higher mean copeptin levels in HF vs. non-HF populations (43.6 ± 46.4 vs. 21.4 ± 21.4; MD= 20.48; 95%CI: 9.22 to 31.74; p < 0.001). Pooled analysis of copeptin concentrations stratified by ejection fraction showed higher concentrations in HFrEF vs. HFpEF (17.4 ± 7.1 vs. 10.1 ± 5.5; MD= -4.69; 95%CI: -7.58 to -1.81; p = 0.001). Copeptin level was higher in patients with mortality/acute HF-related hospitalization vs. stable patients (31.3 ± 23.7 vs. 20.4 ± 12.8; MD= -13.06; 95%CI: -25.28 to -0.84; p = 0.04). Higher copeptin concentrations were associated with mortality and observed in all follow-up periods (p <0.05). Discussion and Conclusions: Present meta-analysis showed that elevated copeptin plasma concentrations observed in HF patients are associated with increased risk of all-cause mortality, thus copeptin may serve as predictor of outcome in HF.

Copeptin as a Diagnostic and Prognostic Biomarker in Cardiovascular Diseases

Copeptin is the carboxyl-terminus of the arginine vasopressin (AVP) precursor peptide. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis, and regulation of endocrine stress response. Copeptin, which is released in an equimolar mode with AVP from the neurohypophysis, has emerged as a stable and simple-to-measure surrogate marker of AVP and has displayed enormous potential in clinical practice. Cardiovascular disease (CVD) is currently recognized as a primary threat to the health of the population worldwide, and thus, rapid and effective approaches to identify individuals that are at high risk of, or have already developed CVD are required. Copeptin is a diagnostic and prognostic biomarker in CVD, including the rapid rule-out of acute myocardial infarction (AMI), mortality prediction in heart failure (HF), and stroke. This review summarizes and discusses the value of copeptin in the diagnosis, discrimination, and prognosis of CVD (AMI, HF, and stroke), as well as the caveats and prospects for the application of this potential biomarker.

Biomarkers of Volume Overload and Edema in Heart Failure With Reduced Ejection Fraction

From a pathogenetic point of view, heart failure (HF) is characterized by the activation of several neurohumoral pathways with a role in maintaining the cardiac output and the adequate perfusion pressure in target organs and tissues. Decreased cardiac output in HF with reduced ejection fraction causes activation of the sympathetic nervous system, the renin angiotensin aldosterone system, arginine-vasopressin system, natriuretic peptides, and endothelin, all of which cause water and salt retention in the body. As a result, patients will present clinically as the main symptoms: dyspnea and peripheral edema caused by fluid redistribution to the lungs and/or by fluid overload. By studying these pathophysiological mechanisms, biomarkers with a prognostic and therapeutic role in the management of edema were identified in patients with HF with low ejection fraction. This review aims to summarize the current data from the specialty literature of such biomarkers with a role in the pathogenesis of edema in HF with low ejection fraction. These biomarkers may be the basis for risk stratification and the development of new therapeutic means in the treatment of edema in these patients.

Translational studies of adrenomedullin and related peptides regarding cardiovascular diseases

Adrenomedullin (AM) is a vasodilative peptide with various physiological functions, including the maintenance of vascular tone and endothelial barrier function. AM levels are markedly increased during severe inflammation, such as that associated with sepsis; thus, AM is expected to be a useful clinical marker and therapeutic agent for inflammation. However, as the increase in AM levels in cardiovascular diseases (CVDs) is relatively low compared to that in infectious diseases, the value of AM as a marker of CVDs seems to be less important. Limitations pertaining to the administrative route and short half-life of AM in the bloodstream (<30 min) restrict the therapeutic applications of AM for CVDs. In early human studies, various applications of AM for CVDs were attempted, including for heart failure, myocardial infarction, pulmonary hypertension, and peripheral artery disease; however, none achieved success. We have developed AM as a therapeutic agent for inflammatory bowel disease in which the vasodilatory effect of AM is minimized. A clinical trial evaluating this AM formulation for acute cerebral infarction is ongoing. We have also developed AM derivatives that exhibit a longer half-life and less vasodilative activity. These AM derivatives can be administered by subcutaneous injection at long-term intervals. Accordingly, these derivatives will reduce the inconvenience in use compared to that for native AM and expand the possible applications of AM for treating CVDs. In this review, we present the latest translational status of AM and its derivatives.

Vasopressin and Breathing: Review of Evidence for Respiratory Effects of the Antidiuretic Hormone

Vasopressin (AVP) is a key neurohormone involved in the regulation of body functions. Due to its urine-concentrating effect in the kidneys, it is often referred to as antidiuretic hormone. Besides its antidiuretic renal effects, AVP is a potent neurohormone involved in the regulation of arterial blood pressure, sympathetic activity, baroreflex sensitivity, glucose homeostasis, release of glucocorticoids and catecholamines, stress response, anxiety, memory, and behavior. Vasopressin is synthesized in the paraventricular (PVN) and supraoptic nuclei (SON) of the hypothalamus and released into the circulation from the posterior lobe of the pituitary gland together with a C-terminal fragment of pro-vasopressin, known as copeptin. Additionally, vasopressinergic neurons project from the hypothalamus to the brainstem nuclei. Increased release of AVP into the circulation and elevated levels of its surrogate marker copeptin are found in pulmonary diseases, arterial hypertension, heart failure, obstructive sleep apnoea, severe infections, COVID-19 due to SARS-CoV-2 infection, and brain injuries. All these conditions are usually accompanied by respiratory disturbances. The main stimuli that trigger AVP release include hyperosmolality, hypovolemia, hypotension, hypoxia, hypoglycemia, strenuous exercise, and angiotensin II (Ang II) and the same stimuli are known to affect pulmonary ventilation. In this light, we hypothesize that increased AVP release and changes in ventilation are not coincidental, but that the neurohormone contributes to the regulation of the respiratory system by fine-tuning of breathing in order to restore homeostasis. We discuss evidence in support of this presumption. Specifically, vasopressinergic neurons innervate the brainstem nuclei involved in the control of respiration. Moreover, vasopressin V1a receptors (V1aRs) are expressed on neurons in the respiratory centers of the brainstem, in the circumventricular organs (CVOs) that lack a blood-brain barrier, and on the chemosensitive type I cells in the carotid bodies. Finally, peripheral and central administrations of AVP or antagonists of V1aRs increase/decrease phrenic nerve activity and pulmonary ventilation in a site-specific manner. Altogether, the findings discussed in this review strongly argue for the hypothesis that vasopressin affects ventilation both as a blood-borne neurohormone and as a neurotransmitter within the central nervous system.

Copeptin and Stress

Vasopressin (AVP) and copeptin are released in equimolar amounts from the same precursor. Due to its molecular stability and countless advantages as compared with AVP, copeptin perfectly mirrors AVP presence and has progressively emerged as a reliable marker of vasopressinergic activation in response to osmotic and hemodynamic stimuli in clinical practice. Moreover, evidence highlighting the prognostic potential of copeptin in several acute diseases, where the activation of the AVP system is primarily linked to stress, as well as in psychologically stressful conditions, has progressively emerged. Furthermore, organic stressors induce a rise in copeptin levels which, although non-specific, is unrelated to plasma osmolality but proportional to their magnitude: suggesting disease severity, copeptin proved to be a reliable prognostic biomarker in acute conditions, such as sepsis, early post-surgical period, cardiovascular, cerebrovascular or pulmonary diseases, and even in critical settings. Evidence on this topic will be briefly discussed in this article.

Lipid Metabolite Biomarkers in Cardiovascular Disease: Discovery and Biomechanism Translation from Human Studies

Lipids represent a valuable target for metabolomic studies since altered lipid metabolism is known to drive the pathological changes in cardiovascular disease (CVD). Metabolomic technologies give us the ability to measure thousands of metabolites providing us with a metabolic fingerprint of individual patients. Metabolomic studies in humans have supported previous findings into the pathomechanisms of CVD, namely atherosclerosis, apoptosis, inflammation, oxidative stress, and insulin resistance. The most widely studied classes of lipid metabolite biomarkers in CVD are phospholipids, sphingolipids/ceramides, glycolipids, cholesterol esters, fatty acids, and acylcarnitines. Technological advancements have enabled novel strategies to discover individual biomarkers or panels that may aid in the diagnosis and prognosis of CVD, with sphingolipids/ceramides as the most promising class of biomarkers thus far. In this review, application of metabolomic profiling for biomarker discovery to aid in the diagnosis and prognosis of CVD as well as metabolic abnormalities in CVD will be discussed with particular emphasis on lipid metabolites.

Heart Failure and Diabetes Mellitus: Biomarkers in Risk Stratification and Prognostication

Heart failure (HF) and type 2 diabetes mellitus (T2DM) have a synergistic effect on cardiovascular (CV) morbidity and mortality in patients with established CV disease (CVD). The aim of this review is to summarize the knowledge regarding the discriminative abilities of conventional and novel biomarkers in T2DM patients with established HF or at higher risk of developing HF. While conventional biomarkers, such as natriuretic peptides and high-sensitivity troponins demonstrate high predictive ability in HF with reduced ejection fraction (HFrEF), this is not the case for HF with preserved ejection fraction (HFpEF). HFpEF is a heterogeneous disease with a high variability of CVD and conventional risk factors including T2DM, hypertension, renal disease, older age, and female sex; therefore, the extrapolation of predictive abilities of traditional biomarkers on this population is constrained. New biomarker-based approaches are disputed to be sufficient for improving risk stratification and the prediction of poor clinical outcomes in patients with HFpEF. Novel biomarkers of biomechanical stress, fibrosis, inflammation, oxidative stress, and collagen turn-over have shown potential benefits in determining prognosis in T2DM patients with HF regardless of natriuretic peptides, but their role in point-to-care and in routine practice requires elucidation in large clinical trials.

Copeptin reliably reflects longitudinal right ventricular function

BACKGROUND

Data is limited evaluating novel biomarkers in right ventricular dysfunction. Normal right heart function improves the prognosis of patients with heart failure. Therefore, this study investigates the association between the novel biomarker copeptin and right heart function compared to NT-proBNP.

METHODS

Patients undergoing routine echocardiography were enrolled prospectively. Right ventricular function was assessed by tricuspid annular plane systolic excursion (TAPSE) and further right ventricular and atrial parameters. Exclusion criteria were age under 18 years, left ventricular ejection fraction < 50% and moderate to severe valvular heart disease. Blood samples were taken for biomarker measurements within 72 h of echocardiography.

RESULTS

Ninety-one patients were included. Median values of copeptin increased significantly according to decreasing values of TAPSE (P = 0.001; right heart function grade I: tricuspid annular plane systolic excursion; TAPSE > 24 mm: 5.20 pmol/L; grade II: TAPSE 18-24 mm: 8.10 pmol/L; grade III: TAPSE < 18 mm: 26.50 pmol/L). Copeptin concentrations were able to discriminate patients with decreased right heart function defined as TAPSE < 18 mm (area under the curves [AUC]: copeptin: 0.793; P = 0.001; NT-proBNP: 0.805; P = 0.0001). Within a multivariable linear regression model, copeptin was independently associated with TAPSE (copeptin: T: -4.43; P = 0.0001; NT-proBNP: T: -1.21; P = 0.23). Finally, copeptin concentrations were significantly associated with severely reduced right heart function (TAPSE < 18 mm) within a multivariate logistic regression model (copeptin: odds ratio: 0.94; 95% confidence interval: 0.911-0.975; P = 0.001).

CONCLUSIONS

This study demonstrates that the novel biomarker copeptin reflects longitudinal right heart function assessed by standardized transthoracic echocardiography compared with NT-proBNP.

Gender-based differences of copeptin alone or combined with troponin for early rule-out of non-ST-elevation myocardial infarction

BACKGROUND

Little is known about the role of gender in the dual biomarker strategy using copeptin and troponin for the early rule-out of non-ST-elevation myocardial infarction (NSTEMI). We aimed to evaluate gender-based differences on copeptin levels, combined negative predictive value (NPV) and predictors of copeptin elevation at admission.

METHODS

Biomarkers were measured in 852 adult patients presenting to the emergency department with chest pain and suspected NSTEMI. Logistic regression analyses on predictors of copeptin elevation were evaluated by gender.

RESULTS

Overall, 362 women (42.5%) and 490 men (57.5%) were included. Copeptin levels were higher in men (median 7.36 pmol/L vs. 4.8 pmol/L; P < .001). Men had a similar NPV (100%) as women (99.6%, CI: 98.8-100) using the dual biomarker rule-out strategy and when compared to troponin alone (men, NPV = 98.7%, CI: 97.5-99.8; and women, NPV = 98.7%, CI: 97.5-100). Multivariate logistic regression showed positive association of male gender with copeptin elevation (OR = 2.37; CI: 1.61-3.49; P < .001). In men, diastolic blood pressure was a negative predictor of copeptin elevation (OR = 0.98, 95% CI: 0.96-0.99), while positive predictors were current MI (OR = 2.16, 95% CI: 1.19-3.91), chronic renal insufficiency (OR = 3.58, 95% CI: 1.33-9.62), and atrial fibrillation (OR = 2.56, 95% CI: 1.23-5.32), respectively (all P < .05). In women, current MI (OR = 2.98, CI: 1.23-7.24), atrial fibrillation (OR = 2.90, CI: 1.26-6.70) and syncope-like events (OR = 7.56, CI: 2.26-25.30) were significant predictors of copeptin elevation.

CONCLUSIONS

Men with suspected NSTEMI have higher copeptin levels. The dual biomarker rule-out strategy has a similar performance in both male and female patients. Certain predictors of copeptin elevation are gender-specific.

The therapeutic effect of B-type natriuretic peptides in acute decompensated heart failure

B-type natriuretic peptide (BNP) exhibits roles in natriuresis and diuresis, making it an ideal drug that may aid in diuresing a fluid-overloaded patient with poor or worsening renal function. Several randomized clinical trials have tested the hypothesis that infusions of pharmacological doses of BNP to acute heart failure (HF) patients may enhance decongestion and preserve renal function in this clinical setting. Unfortunately, none of these have demonstrated beneficial outcomes. The current challenge for BNP research in acute HF lies in addressing a failure of concept and a reluctance to abandon an ineffective research model. Future success will necessitate a detailed understanding of the mechanism of action of BNP, as well as better integration of basic and clinical science.

Cardiac Biomarkers in Advanced Heart Failure: How Can They Impact Our Pre-transplant or Pre-LVAD Decision-making

PURPOSE OF REVIEW

Decision-making in advanced heart failure (HF) is a complex process that involves careful consideration of competing tradeoffs of risks and benefits in regard to heart transplantation (HT) or left ventricular assist device (LVAD) placement. The purpose of this review is to discuss how biomarkers may affect decision-making for HT or LVAD implantation.

RECENT FINDINGS

N-Terminal probrain natriuretic peptide, soluble suppression of tumorigenicity-2, galectin-3, copeptin, and troponin T levels are associated with HF survival and can help identify the appropriate timing for advanced HF therapies. Patients at risk of right ventricular failure after LVAD implantation can be identified with preimplant biomarkers of extracellular matrix turnover, neurohormonal activation, and inflammation. There is limited data on the adoption of biomarker measurement for decision-making in the allocation of advanced HF therapies. Nonetheless, biomarkers can improve risk stratification and prognostication thereby optimizing patient selection for HT and LVAD implantation.

Early NT-proBNP and MR-proANP associated with QoL 1 year after acutely decompensated heart failure: secondary analysis from the MOLITOR trial

Aim: Heart failure negatively impacts quality of life (QoL), which in turn contributes to an adverse long-term prognosis. We aimed at identifying biomarker trajectories after an episode of acutely decompensated heart failure (ADHF) that differ between patients showing average versus impaired QoL 1 year later, thus allowing to predict impaired QoL. Methods: Biomarkers were repeatedly measured throughout the year in 104 ADHF patients. QoL was assessed at discharge and 1 year after ADHF. Logistic regression and receiver operating characteristic analyses were used to identify predictors of impaired QoL while controlling psychosocial confounders. Results: MR-proANP predicted impaired physical and mental QoL. NT-proBNP measurements were important predictors for poor physical QoL. Conclusion: MR-proANP and NT-proBNP predict poor QoL after an epidode of ADHF. The trial is registered at http://clinicaltrials.gov as MOLITOR (IMpact of therapy optimisation On the Level of biomarkers in paTients with Acute and Decompensated ChrOnic HeaRt Failure) with unique identifier: NCT01501981.

The β-blocker uptitration in elderly with heart failure regarding biomarker levels: CIBIS-ELD substudy

AIM

We investigated if the baseline value of mid-regional pro-atrial natriuretic peptide (NP), N-terminal pro-B-type NP and copeptin may be helpful in optimizing β-blocker uptitration in elderly patients with heart failure.

PATIENTS & METHODS

According to the biomarkers' levels, 457 patients were divided into three subgroups and compared with each other at baseline and 3 months after.

RESULTS

All mid-regional pro-atrial NP and N-terminal pro-B-type NP subgroups had significant amelioration of left ventricle ejection fraction and New York Heart Association (NYHA) class after 3 months of β-blocker uptitration (p < 0.001). More prominent improvement of left ventricle ejection fraction and New York Heart Association class was observed in subgroups with lower versus higher NPs levels.

CONCLUSION

NPs levels, unlike copeptin levels, might be useful tool for objective selection of elderly heart failure patients who could have the greatest benefit of forced uptitration.

The clinical application value of the plasma copeptin level in the assessment of heart failure with reduced left ventricular ejection fraction: A cross-sectional study

This study aimed to evaluate the clinical applicability of the plasma copeptin level to assess heart failure with reduced left ventricular ejection fraction (HFrEF).One hundred thirty-one patients with HFrEF, 127 patients with heart failure with preserved left ventricular ejection fraction (HFpEF), and 119 healthy candidates were involved. The basic data and examination results of patients were collected. The heart function of the patients with HFrEF and HFpEF were graded on the basis of the criteria of New York Heart Association (NYHA) classification. The plasma copeptin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were tested using enzyme-linked immunosorbent assays (ELISAs).The copeptin and NT-proBNP levels were higher in the HFrEF group than in the HFpEF group. The copeptin and NT-proBNP values increased as the NYHA grade increased in the patients with HFrEF. However, for the patients with HFpEF, the copeptin levels did not change markedly as the NYHA grade increased. The copeptin levels were positively correlated with the NT-proBNP levels in the patients with HFrEF; however, there was no correlation between the copeptin and NT-proBNP values in the patients with HFpEF.Copeptin is involved in the process of progression in patients with HFrEF and the copeptin values might be useful for HFrEF prediction and assessment in the clinic.

Prognostic performance of serial in-hospital measurements of copeptin and multiple novel biomarkers among patients with worsening heart failure: results from the MOLITOR study

Aims

In heart failure, various biomarkers are established for diagnosis and risk stratification; however, little is known about the relevance of serial measurements during an episode worsening heart failure (WHF). This study sought to investigate the trajectory of natriuretic peptides and multiple novel biomarkers during hospitalization for WHF and to determine the best time point to predict outcome.

Methods and results

MOLITOR (Impact of Therapy Optimisation on the Level of Biomarkers in Patients with Acute and Decompensated Chronic Heart Failure) was an eight‐centre prospective study of 164 patients hospitalized with a primary diagnosis of WHF. C‐terminal fragment of pre‐pro‐vasopressin (copeptin), N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP), mid‐regional pro‐atrial natriuretic peptide (MR‐proANP), mid‐regional pro‐adrenomedullin (MR‐proADM), and C‐terminal pro‐endothelin‐1 (CT‐proET1) were measured on admission, after 24, 48, and 72 h, and every 72 h thereafter, at discharge and follow‐up visits. Their performance to predict all‐cause mortality and rehospitalization at 90 days was compared. All biomarkers decreased during recompensation (P < 0.05) except MR‐proADM. Copeptin at admission was the best predictor of 90 day mortality or rehospitalization (χ² = 16.63, C‐index = 0.724, P < 0.001), followed by NT‐proBNP (χ² = 10.53, C‐index = 0.646, P = 0.001), MR‐proADM (χ² = 9.29, C‐index = 0.686, P = 0.002), MR‐proANP (χ² = 8.75, C‐index = 0.631, P = 0.003), and CT‐proET1 (χ² = 6.60, C‐index = 0.64, P = 0.010). Re‐measurement of copeptin at 72 h and of NT‐proBNP at 48 h increased prognostic value (χ² = 23.48, C‐index = 0.718, P = 0.00001; χ² = 14.23, C‐index = 0.650, P = 0.00081, respectively).

Conclusions

This largest sample of serial measurements of multiple biomarkers in WHF found copeptin at admission with re‐measurement at 72 h to be the best predictor of 90 day mortality and rehospitalization.