# Investigation of the interplay of PCSK9, cardiac dynamics, oxidative stress in coronary artery disease: case-control study

## TL;DR

This study explores how PCSK9, heart function, and oxidative stress are linked in heart attack patients, finding that markers like ox-LDL and EF% are better predictors of coronary artery blockage than PCSK9 or LDL-C.

## Contribution

The study reveals that oxidative stress markers and heart function indicators are more predictive of coronary artery blockage than traditional lipid markers like PCSK9 and LDL-C.

## Key findings

- Ox-LDL and EF% are better predictors of coronary artery blockage than hs-cTnI.
- PCSK9 correlates with oxidative stress markers like MDA, even when LDL-C levels are normal.
- Higher antioxidant levels (TAC, GPx, CAT, SOD) are associated with lower risk of significant coronary blockage.

## Abstract

PCSK9 plays a key role in raising LDL-C levels, which contributes to heart attacks (MI). However, studies show that about half of MI patients have normal LDL-C levels. This study aims to explore the link between PCSK9, heart function, and oxidative stress markers in MI patients.

This investigation was carried out at Tehran Heart Centre Hospital on healthy individuals (n=63) and patients (n=63) with MI who had a coronary artery block above 50% (CAB > 50%). Oxidative stress (OS) parameters, such as total antioxidant capacity (TAC), malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity, PCSK9, oxidized Low-density lipoprotein (ox-LDL), high-sensitivity cardiac troponin I (hs-cTnI), and hs-CRP are assessed. Indeed, biochemical parameters and EF% were measured.

Higher EF% (>37.5%), TAC (>1.05 mmol Fe²+;/L), GPx (>16.48 mU/mL), CAT (>11.32 nmol/min/mL), and SOD (>297.16 U/mL) were linked to a lower risk of CAB > 50%. In contrast, higher MDA (>32.07 nmol/mL), MPO (>17.77 U/L), hs-CRP (>5.5 mg/L), and ox-LDL (>64.87 μg/L) were associated with a higher risk. There was no significant difference in PCSK9 and LDL-C levels between groups. EF% was positively linked to SOD but negatively related to MDA, MPO, ox-LDL, hs-cTnI, and hs-CRP. Ox-LDL correlated positively with MPO but negatively with TAC, CAT, and GPx. PCSK9 showed a positive relationship with MDA. The best markers for CAB > 50% diagnosis were ox-LDL (AUC = 83.22, cut-off > 63.35 μg/L), EF% (AUC = 82.35, cut-off < 46.25%), and hs-cTnI (AUC = 81.3, cut-off > 0.265 ng/mL).

While PCSK9’s role in MI through LDL-C is well known, its impact on inflammation and oxidative stress may also be important, even when LDL-C and PCSK9 levels are normal. Additionally, ox-LDL and EF% are better indicators of CAB > 50% than hs-cTnI.