Differences in Metabolic Profiles of Individuals with Heart Failure Using High Resolution GC/Q-TOF

Importance of Metabolic Profiling in Heart Failure

Metabolic dysregulation lies at the core of heart failure pathophysiology and influences both disease progression and treatment response. Heart failure affects over 23 million people globally and comprises two main subtypes: reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). While therapies exist for HFrEF, effective interventions for HFpEF remain limited. Untargeted metabolic profiling can reveal biochemical alterations that underlie these subtypes, guide biomarker discovery, and support development of new therapeutic strategies.

Objectives and Study Overview

This study aimed to characterize plasma metabolic signatures in individuals with HFrEF and HFpEF compared to healthy controls, using high‐resolution gas chromatography/quadrupole time‐of‐flight mass spectrometry (GC/Q‐TOF). Key objectives included:

• Perform untargeted profiling to detect differential metabolites between heart failure patients and healthy individuals.
• Identify unique metabolic features distinguishing HFrEF from HFpEF.
• Elucidate unknown metabolites elevated in heart failure for potential mechanistic insight.

Methodology and Instrumentation

Plasma samples (n=10 per group) were extracted with acetonitrile:isopropanol:water (3:3:2), dried, and derivatized by O-methoximation and trimethylsilylation (MSTFA + 1% TMCS). Analytical workflow:

• Instrumentation: Agilent 8890 GC coupled to Agilent 7250 Q-TOF mass spectrometer.
• Column: DB-5MS UI (30 m × 0.25 mm × 0.25 µm) with 10 m DuraGuard insert.
• GC conditions: inlet at 280 °C, splitless 0.2 µL injection, oven ramp from 50 °C to 325 °C at 10 °C/min with a 10 min hold.
• MS conditions: electron ionization at 70 eV, mass range 50–1200 m/z, acquisition rate 5 Hz.
• Data processing: MassHunter Unknowns Analysis for deconvolution and library matching (Accurate Mass Metabolomics PCDL, Fiehn, NIST20). Statistical comparisons conducted in Mass Profiler Professional (MPP) and structure elucidation via Molecular Structure Correlator (MSC).

Results and Discussion

PCA revealed a clear separation between heart failure subjects and healthy controls, indicating distinct metabolic footprints. Volcano plot and fold‐change analyses identified over 40 compounds contributing to group differences:

• Controls exhibited higher levels of various amino acids.
• Heart failure subjects showed elevated organic acids, select sterols, and nitrogen‐containing compounds.
• Subgroup comparison highlighted iminodiacetic acid as more abundant in HFpEF than HFrEF.

Structure elucidation of an unknown marker in heart failure plasma, using positive chemical ionization and EI-MS/MS, suggested a pyrimidine-2,4,6-triol candidate, offering new insight into disease‐related pathways.

Benefits and Practical Applications

This untargeted GC/Q-TOF approach:

• Provides comprehensive coverage of small metabolites relevant to cardiac dysfunction.
• Enables discovery of candidate biomarkers for heart failure diagnosis and subtyping.
• Supports mechanistic investigations to inform therapeutic target identification.
• Can be adapted for routine QC and clinical research laboratories seeking high-resolution metabolite profiling.

Future Trends and Potential Applications

Emerging directions include:

• Integration with other omics (proteomics, transcriptomics) for systems-level understanding.
• Validation in larger cohorts to establish robust biomarker panels.
• Development of targeted assays for clinical translation and longitudinal monitoring.
• Application of machine learning for pattern recognition and predictive modeling.

Conclusion

High-resolution GC/Q-TOF metabolomics distinguished heart failure patients from healthy individuals and identified subtype-specific metabolic alterations. The study uncovered over 40 differential metabolites, including amino acids, organic acids, sterols, and a novel pyrimidine derivative. These findings lay the groundwork for biomarker development and therapeutic research in heart failure.

Reference

1. Funk M. Epidemiology of heart failure. Crit Care Nurs Clin North Am. 1993;5(4):569–573.
2. Borlaug BA, Paulus WJ. Heart failure with preserved ejection fraction: pathophysiology, diagnosis, and treatment. Eur Heart J. 2011;32(6):670–679.