Blood enzyme GSTP-1 tracks heart failure severity in emergency patients

Adults arriving at hospital with decompensated heart failure show rising blood levels of a detoxification enzyme as their functional limitation worsens, according to a prospective observational study published in BMC Cardiovascular Disorders.

The enzyme, glutathione S-transferase pi 1 (GSTP-1), participates in glutathione-dependent detoxification and stress signalling. Its relationship with pre-presentation functional limitation in decompensated heart failure had been uncertain, which motivated the research team led by Elif Kahveci Küçük to measure serum concentrations across New York Heart Association (NYHA) functional classes and, secondarily, to examine whether levels were associated with emergency department disposition.

The single-centre study enrolled 120 adults presenting with decompensated heart failure, either de novo or as worsening of pre-existing heart failure. Recruitment used a prespecified quota of 30 participants per NYHA class, and eligible consenting patients were enrolled consecutively while the relevant class quota remained open. Eligibility required a compatible decompensated clinical syndrome and objective evidence of congestion.

Diagnosis was informed by B-type natriuretic peptide, posteroanterior chest radiography, and tranthoracic echocardiography, with echocardiography performed during the index presentation in all 120 patients. Serum GSTP-1 was measured with a research-use-only ELISA, a detail the authors emphasise because the assay is not a clinically validated test.

This graded pattern suggests the enzyme’s circulating level tracks the severity of functional limitation patients reported before arriving at the hospital.

Disposition data were available for 119 patients, of whom 36 were discharged and 83 were admitted. GSTP-1 also increased across discharge, ward admission, and intensive care admission, at 51.10, 66.18, and 94.65 ng/mL respectively, again with an overall p value below 0.001.

In an exploratory model using a selected four-variable reference model rather than a validated clinical prediction model, each 10-ng/mL increase in GSTP-1 was associated with higher odds of admission, with an adjusted odds ratio of 1.36 (95% confidence interval 1.14 to 1.63; p < 0.001). Adding GSTP-1 also improved nested-model fit, with a likelihood-ratio χ² of 14.47 (p < 0.001). The authors note that these admission analyses, conducted in the 119 patients with known disposition, were post hoc and exploratory.

The researchers were careful to qualify what these estimates do and do not show. NYHA-adjusted estimates were treated as consistency checks only, because the quota-based construction of the cohort and sparse outcomes within individual classes precluded separating residual confounding. The admission findings, they write, provide hypothesis-generating, cohort-conditional statistical information; they do not establish haemodynamic severity of the index decompensation, clinical prediction, or decision-making utility.

Those caveats matter for interpretation. A prospective observational study can describe associations but cannot prove that GSTP-1 causes worse outcomes or that measuring it would improve triage decisions. The quota sampling design, the single-centre setting, and the research-use-only assay all limit how far the results can be generalised to other hospitals or to routine clinical practice.

The authors conclude that serum GSTP-1 showed a graded association with pre-presentation NYHA functional class and was associated with emergency department disposition in this quota-constructed cohort. They call for confirmation in unselected multicentre cohorts using clinically validated assays and serial sampling before any clinical application can be considered.

Subject of Research: Serum GSTP-1 levels and their association with heart failure severity and emergency department disposition

Article Title: Associations of serum glutathione S-transferase pi 1 with NYHA functional class and emergency department disposition in decompensated heart failure: a prospective observational study

Article References: Küçük, E. K., Çeliktürk, E., Sayhan, M. B., Gök, M., Bozatlı, S. B. H., & Çalın, S. (2026). Associations of serum glutathione S-transferase pi 1 with NYHA functional class and emergency department disposition in decompensated heart failure: a prospective observational study. BMC Cardiovascular Disorders. https://doi.org/10.1186/s12872-026-06936-w

Image Credits: AI Generated

DOI: 10.1186/s12872-026-06936-w

Keywords: GSTP-1, decompensated heart failure, NYHA functional class, emergency department, biomarker, prospective observational study, oxidative stress, ELISA, hospital admission, cardiology, Associations, serum