Introduction to Acute Heart Failure Biomarkers

Congestion remains the primary driver of hospital admissions and adverse outcomes in patients with cardiac dysfunction. While clinical assessment is fundamental, it often fails to detect subclinical fluid overload. Consequently, physicians rely heavily on natriuretic peptides for objective data. However, these markers primarily reflect myocardial wall stress rather than direct systemic congestion. This limitation has spurred significant research into more precise acute heart failure biomarkers that can better quantify fluid status and predict long-term mortality. Recent systematic reviews have synthesized evidence on several emerging molecules that offer mechanistically complementary insights. These markers include Carbohydrate Antigen 125, Adrenomedullin, Soluble ST2, and Soluble CD146. Understanding their specific roles can help clinicians refine decongestive strategies and improve risk stratification. By moving beyond a single-marker approach, the medical community aims to achieve a more nuanced understanding of heart failure pathophysiology. This article explores how these novel indicators are transforming the management of acute heart failure in modern clinical practice.

Carbohydrate Antigen 125: A Marker for Systemic Congestion

Carbohydrate Antigen 125, traditionally known as an ovarian cancer marker, has emerged as a powerful tool for assessing systemic congestion. Unlike natriuretic peptides, CA-125 is synthesized by mesothelial cells in response to mechanical stress and inflammatory stimuli. When fluid accumulates in the serosal cavities, such as the pleura or peritoneum, these cells release the antigen into the bloodstream. Therefore, CA-125 levels correlate strongly with physical signs of systemic venous congestion, including peripheral edema and ascites. Multiple clinical studies demonstrate that higher admission levels of CA-125 predict a significantly increased risk of mortality and rehospitalization. Furthermore, the CHANCE-HF trial suggested that CA-125 can effectively guide diuretic therapy. Monitoring the decline of this biomarker during hospitalization helps clinicians ensure that true decongestion has occurred before discharge. Because CA-125 has a relatively long half-life of approximately one week, it reflects cumulative fluid status rather than instantaneous changes. This characteristic makes it an excellent tool for long-term monitoring and risk assessment in complex heart failure cases where physical signs are ambiguous.

Adrenomedullin and its Derivatives in Hemodynamic Assessment

Adrenomedullin is a potent vasodilatory hormone produced by endothelial and vascular smooth muscle cells. It plays a vital role in maintaining vascular integrity and regulating fluid balance during periods of cardiovascular stress. Specifically, biologically active adrenomedullin reflects rapid hemodynamic changes and the severity of residual congestion at the time of hospital discharge. However, its short half-life makes direct measurement technically challenging in routine clinical settings. To overcome this, researchers often utilize mid-regional proadrenomedullin as a more stable surrogate for prognostic purposes. High levels of these acute heart failure biomarkers are consistently associated with organ dysfunction and poor clinical outcomes. In many cases, elevated adrenomedullin levels persist even after clinical signs of fluid overload have resolved. This persistence indicates subclinical congestion that requires further therapeutic intervention. By identifying patients with high residual vascular stress, clinicians can tailor aggressive decongestion protocols to prevent early readmission. Current evidence highlights that incorporating adrenomedullin into standard protocols enhances the accuracy of risk stratification and provides a clearer picture of the patient's hemodynamic profile.

Soluble Suppression of Tumorigenicity-2 for Risk Stratification

Soluble suppression of tumorigenicity-2 is a member of the interleukin-1 receptor family that serves as a marker of myocardial strain and inflammation. In the context of acute heart failure, sST2 levels rise dramatically in response to ventricular stretch and fibro-inflammatory processes. Unlike natriuretic peptides, sST2 is not significantly influenced by age, body mass index, or impaired renal function. This independence makes it a robust and reliable indicator for a broad patient population. Clinical data suggest that a dynamic decline in sST2 during hospitalization is a strong predictor of survival. Conversely, patients who fail to show a decrease in sST2 levels despite intensive therapy are at the highest risk for adverse events. Moreover, sST2 provides valuable prognostic information that is independent of and additive to natriuretic peptides. This biomarker helps clinicians identify the most vulnerable patients who may benefit from more intensive monitoring or advanced therapies. By reflecting the underlying biological response to cardiac injury, sST2 acts as a vital bridge between mechanical congestion and cellular inflammation in heart failure management.

Soluble CD146 and Peripheral Venous Stress

Soluble CD146 is a novel endothelial marker that has gained attention for its specific association with systemic venous congestion. It is released from the peripheral vasculature in response to venous stretch induced by volume overload. Mechanistic studies have shown that sCD146 levels increase specifically during venous stress, whereas natriuretic peptides remain more linked to intracardiac pressures. Consequently, sCD146 offers a unique window into the status of the peripheral circulation. This biomarker demonstrates additional diagnostic value in scenarios where natriuretic peptides might underperform, such as in patients with acute dyspnea of non-cardiac origin. Its strong correlation with clinical signs of congestion makes it an ideal candidate for monitoring the effectiveness of diuretic treatment. Furthermore, elevated sCD146 levels at discharge are predictive of poor long-term outcomes, suggesting its utility in identifying patients with incomplete decongestion. Integrating sCD146 into the diagnostic toolkit allows for a more comprehensive assessment of the entire vascular system. This multi-organ perspective is essential for managing the complex interplay between the heart and the peripheral vessels in acute heart failure.

Implementing Acute Heart Failure Biomarkers in Practice

The integration of these various acute heart failure biomarkers represents a significant shift toward precision medicine in cardiology. Relying solely on a single marker like NT-proBNP may overlook critical aspects of the patient's pathophysiological state. For instance, combining CA-125 with sST2 allows clinicians to monitor both systemic congestion and myocardial inflammation simultaneously. This multi-biomarker approach provides a more holistic view of the patient’s clinical trajectory and helps in identifying specific phenotypes of heart failure. Although many of these markers are currently used primarily in research, their diagnostic and prognostic power is undeniable. Future clinical practice will likely involve standardized panels that include several of these molecules to guide decongestion and optimize discharge planning. However, larger prospective trials are still necessary to fully define the optimal cut-off values and the exact timing for routine measurements. In the meantime, understanding the biological significance of these markers empowers physicians to make more informed decisions at the bedside. Eventually, these tools will help reduce the high rates of rehospitalization that currently plague heart failure management globally.

FAQ: Frequently Asked Questions

How do these emerging biomarkers differ from traditional natriuretic peptides?

Traditional natriuretic peptides primarily indicate myocardial wall stress and intracardiac pressures. In contrast, emerging biomarkers like CA-125 and sCD146 specifically reflect systemic venous congestion and peripheral vascular stretch. Other markers, such as sST2, focus on the inflammatory response and myocardial fibrosis. By using these molecules together, clinicians gain a more complete understanding of both the mechanical and biological aspects of heart failure that natriuretic peptides alone cannot provide.

Can CA-125 be used to guide the dosage of diuretic therapy?

Yes, clinical evidence such as the CHANCE-HF trial suggests that CA-125 can effectively guide decongestive therapy. Because CA-125 levels respond to changes in serosal fluid and systemic congestion, monitoring its trajectory helps clinicians adjust diuretic doses more accurately. A significant decrease in CA-125 levels during treatment usually indicates successful decongestion, whereas persistently high levels suggest that the patient requires more intensive fluid removal before being safely discharged from the hospital.

Why is sST2 considered a superior prognostic marker in certain patient groups?

Soluble ST2 is considered a highly reliable prognostic marker because it remains unaffected by common clinical variables like age, obesity, and renal failure. Natriuretic peptides often provide misleading results in patients with chronic kidney disease or high body mass index. Since sST2 specifically reflects myocardial strain and inflammation, it provides a consistent and clear signal of cardiac distress across diverse populations, making it an invaluable tool for accurate risk stratification in complex clinical scenarios.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice. It is not a substitute for professional medical judgment, diagnosis, or treatment. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

Asaftei A et al. Biomarkers for congestion assessment and prognosis in acute heart failure: A systematic review. Exp Mol Pathol. 2026 Jul 08. doi: undefined. PMID: 42418867.

Januzzi JL Jr et al. sST2 Has Independent Prognostic Value for Patients with Chronic Heart Failure. J Am Coll Cardiol. 2019.

Smith JT. Biomarker-Guided Self-Testing in Heart Failure. Allied Academies. 2025.