# Serum Oxysterol Levels in Heart Failure With Preserved Ejection Fraction: A Prospective Case-Control Study

## TL;DR

This study found higher levels of oxysterols in heart failure patients with preserved ejection fraction, suggesting they could be useful biomarkers.

## Contribution

The study is the first to show elevated oxysterol levels in HFpEF patients and their correlation with NT-proBNP.

## Key findings

- HFpEF patients had significantly higher serum oxysterol levels than controls.
- Oxysterol levels strongly correlated with NT-proBNP concentrations.
- Oxysterols showed weak correlations with BMI and left atrial diameter.

## Abstract

Background: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous clinical syndrome with increasing prevalence and limited targeted therapeutic options. Oxysterols, i.e., oxidative derivatives of cholesterol, have been implicated in various cardiovascular pathologies through pro-apoptotic, pro-inflammatory, and cytotoxic mechanisms. However, their potential role in HFpEF pathophysiology remains unexplored.

Objective: This study aimed to investigate the relationship between serum oxysterol levels and HFpEF, and to evaluate their potential as novel biomarkers in this patient population.

Methods: In this prospective, single-center study, 101 participants were enrolled between September 27, 2022, and March 27, 2023. The study group consisted of 51 patients diagnosed with HFpEF, according to the current European Society of Cardiology (ESC) guidelines, while 50 age- and sex-matched individuals without HFpEF served as controls. Serum levels of 7-ketocholesterol, 25-hydroxycholesterol, and 7α,25-dihydroxycholesterol were measured using liquid chromatography-mass spectrometry (LC/MS). Clinical, biochemical, and echocardiographic parameters were recorded and compared between groups. Correlation analyses were performed to assess the relationship between oxysterol levels and other variables, including N-terminal pro-B-type natriuretic peptide (NT-proBNP) and echocardiographic measurements.

Results: Median serum levels of 7-ketocholesterol, 25-hydroxycholesterol, and 7α,25-dihydroxycholesterol were significantly higher in the HFpEF group compared to controls (p < 0.001 for all). Strong positive correlations were found between oxysterol levels and NT-proBNP concentrations (r = 0.778, r = 0.733, and r = 0.630, respectively; p < 0.001). Additionally, oxysterol levels showed weak positive correlations with body mass index and left atrial diameter. No significant associations were observed between oxysterol levels and comorbidities such as hypertension, diabetes mellitus, hyperlipidemia, or coronary artery disease.

Conclusion: This is the first study to demonstrate significantly elevated serum oxysterol levels in HFpEF patients compared to healthy controls. The strong correlation with NT-proBNP suggests that oxysterols may serve as potential biomarkers for HFpEF, reflecting underlying pathophysiological mechanisms involving inflammation and myocardial remodeling. Larger, multicenter studies are warranted to confirm these findings and explore their prognostic value.