Heart failure (HF) is a chronic clinical syndrome characterized by impaired cardiac output, leading to substantial morbidity and mortality. The condition affects over 64 million people globally, with prevalence expected to rise due to population aging and improved survival from acute cardiovascular events.^{[1, 2]} Despite advances in treatment, HF remains a complex disease with heterogeneous presentations and variable outcomes, complicating prognosis and management. Natriuretic peptides such as BNP and NT-proBNP remain the diagnostic and prognostic gold standard^[3], but growing evidence supports the role of additional biomarkers to improve risk stratification and treatment precision. Several novel markers including galectin-3, soluble ST2, GDF-15, and FGF-23, reflect diverse pathological mechanisms like fibrosis and inflammation, enhancing our understanding of disease progression.^{[4, 5]}

Among emerging candidates, copeptin, the stable C-terminal fragment of pre-provasopressin, has shown promise due to its superior biochemical stability and strong correlation with vasopressin system activity, which is upregulated during hemodynamic stress and neurohormonal activation. Unlike vasopressin, copeptin is reliably measurable and has been linked to adverse outcomes, including mortality, hospitalization, and disease progression in both acute and chronic HF.^{[6, 7]} As the global cardiovascular burden increases, identifying robust, easily accessible biomarkers is critical. Copeptin may offer value not only as a stand-alone prognostic marker but also within multimarker strategies that guide treatment and monitor therapeutic response.^[8] This review explores copeptin’s pathophysiological basis, prognostic value in various HF phenotypes, and its potential clinical utility in personalized management strategies.

A structured literature search was conducted across PubMed, Scopus, and Google Scholar for studies published between January 2010 and March 2025. Search terms included “copeptin,” “heart failure,” “biomarkers,” “vasopressin,” “mortality,” and “prognosis”. Additional sources were identified through reference screening of relevant studies.

Eligible publications met the following criteria:

The following were excluded:

Only original research, systematic reviews, and meta-analyses published in English were included.

The vasopressin system, with arginine vasopressin (AVP) as its primary effector, plays a crucial role in cardiovascular regulation through vasoconstriction, water retention, and neurohormonal modulation. These effects are mediated via V1a, V1b, and V2 receptors, contributing to pathophysiological processes in heart failure such as myocardial hypertrophy, vascular resistance, and fluid overload. Copeptin, a stable C-terminal fragment co-secreted with AVP, offers a reliable surrogate measure of vasopressin activity in clinical settings.^{[4, 5]} In HF, copeptin levels reflect activation of both the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis, driven by decreased cardiac output, ischemia, and hemodynamic stress. This neurohormonal overactivation exacerbates disease progression. Elevated copeptin has been associated with left ventricular dysfunction, increased filling pressures, diastolic dysfunction, and hyponatremia, all linked to adverse HF outcomes.‌^{[10, 11]} Recent studies underscore the predictive value of copeptin beyond traditional markers like ejection fraction. It shows a stronger correlation with global longitudinal strain, ventricular remodeling, and extracellular volume fraction, reflecting subclinical myocardial dysfunction. These associations exist across both reduced and preserved EF phenotypes.^[12.13]

Copeptin also demonstrates a tight relationship with fluid homeostasis. As a vasopressin surrogate, it increases with plasma osmolality changes and precedes clinical congestion, offering early warning of decompensation. In hyponatremia, copeptin elevations forecast sodium decline and predict increased mortality risk. This “copeptin–hyponatremia axis” reflects inappropriate vasopressin secretion due to neurohormonal dysregulation, a hallmark of advanced HF.^[14] Mechanistic studies have identified copeptin as an early trigger in the neurohormonal cascade, preceding the upregulation of the renin–angiotensin–aldosterone system (RAAS) and sympathetic activation. Receptor-level evidence suggests cross-talk between V1a and AT1 receptors, potentially enhancing vasoconstriction and remodeling effects. Additionally, copeptin correlates with markers of endothelial dysfunction, nitric oxide metabolism, and inflammatory stress, supporting its role as a multi-pathway biomarker.^{[15, 16]}

Importantly, copeptin is both biochemically stable and analytically robust. It resists degradation, exhibits minimal diurnal variation, and remains quantifiable across platforms with high sensitivity.^{[7, 8]} This makes it ideal for integration into multimarker HF risk models and clinical decision-making algorithms.

Copeptin, a stable surrogate marker for vasopressin, has shown significant prognostic utility in heart failure. Its levels rise in response to hemodynamic stress and neurohormonal activation, reflecting vasopressin system dysregulation. Across both acute and chronic HF populations, copeptin has demonstrated added value in risk stratification, particularly when used alongside natriuretic peptides.^[17] It is especially useful for identifying high-risk individuals, monitoring treatment response, and anticipating adverse outcomes such as mortality and readmission (Table 1).

A 2024 meta-analysis of 27 studies (n=15,842) confirmed that copeptin doubles the risk of cardiovascular death (pooled HR 2.14). The BEACON-HF study proposed a practical threshold of 25 pmol/L for high-risk stratification. Copeptin’s ability to detect neurohormonal stress and systemic hypoperfusion adds biological depth to its predictive value. Combining copeptin with NT-proBNP improves prognostic accuracy, especially under renal dysfunction or hemodynamic instability. The BIOSTRAT-HF trial demonstrated improved clinical decision-making and fewer adverse events with copeptin-informed care pathways.^{[21, 22]}

Copeptin has emerged as a valuable addition to multimarker strategies in heart failure, complementing NT-proBNP and troponin by capturing neurohormonal activation and osmotic dysregulation. Its prognostic value is evident in acute and chronic settings, particularly for identifying subclinical deterioration and guiding care escalation. However, implementation challenges including assay availability, standardization, and cost-effectiveness must be addressed before widespread adoption.^[23]

The MULTIHEART Registry (2023) and BIOMARKER-HF trial (2024) confirmed that combining copeptin with NT-proBNP and troponin significantly improves prognostic precision, identifying patients with a 4.3-fold higher hazard of adverse events.^[24] Importantly, discordant biomarker profiles by improving BNP but persistent copeptin elevation flag high-risk cases that appear clinically stable. The PRECEDE-HF study showed that copeptin rises ~7 days before overt congestion, offering earlier intervention opportunities than NT-proBNP. In DETECT-HF, weekly copeptin monitoring reduced unplanned hospitalizations by 31%, especially in CKD patients. The copeptin/NT-proBNP ratio is emerging as a novel tool for distinguishing neurohormonal vs. mechanical decompensation.^{[25, 26]}

Trials like BIOGUIDE-AHF and RELEASE incorporated copeptin into triage and discharge protocols, resulting in 23% lower in-hospital mortality and 28% fewer 30-day readmissions, respectively.^{[14, 15]} In COMPASS-HF, elevated outpatient copeptin triggered intensified follow-up, improving outcomes vs. symptom-based care. The tiered STRATEGIZE-HF protocol assigned interventions by copeptin thresholds (10, 20, 30 pmol/L), optimizing resource use.^[27]

Precision medicine applications are expanding: in CARDIOMICS (2024), copeptin stratified patients into molecular subtypes with differential treatment response. Machine learning models such as FORECAST-HF improved 90-day outcome prediction (AUC 0.87 vs. 0.79), and the reinforcement-learning-driven ADAPT-HF individualized therapy using real-time copeptin inputs.^[28]

Despite promising data, copeptin faces limitations that hinder clinical adoption. Cut-off values lack standardization across studies and platforms, reducing comparability. Comorbidities such as chronic kidney disease and sepsis can confound copeptin interpretation. Direct comparisons with other emerging biomarkers like GDF-15 and MR-proADM are limited, and copeptin testing is not widely available. Cost-effectiveness data are still sparse, and assay accessibility varies globally.

Future research should focus on validating copeptin through multicenter trials such as COMPASS-HF and PREDICT-HF, which will help optimize thresholds and stratify patient risk. Integrating copeptin into AI-driven models and multimarker panels may enhance precision in HF management. Further investigation is also needed into its role in HFpEF, cardiorenal syndrome, and advanced interventions (CRT, LVAD). With technological advancement and stronger evidence, copeptin could become a key component of personalized, biomarker-guided HF care.

Copeptin is a promising biomarker for heart failure, offering prognostic value across acute and chronic settings by reflecting neurohormonal stress. Its integration into multimarker panels and targeted use in high-risk patients may enhance risk stratification and treatment. As standardization advances and results from ongoing trials emerge, copeptin holds strong potential to support precision medicine approaches in heart failure care.

The authors do not have any conflicts of interest.

Machineni Sravani and Manickam Kokila contributed equally to this work and share first authorship. Both were involved in the conceptualization, literature review, manuscript drafting, and critical revision for intellectual content. Kasinathan Ramanathan contributed to data interpretation, editing, and final content validation. Arun Kumar supervised the overall project, contributed to manuscript structure and scientific accuracy, and serves as the corresponding author.