# Soluble Guanylate Cyclase Stimulator, BAY41‐8543: A Promising Approach for the Treatment of Chronic Heart Failure Caused by Pressure and Volume Overload

## TL;DR

This study explores how a drug called BAY41-8543 may help treat chronic heart failure by reducing oxidative stress and improving heart function in rats.

## Contribution

The study demonstrates the novel therapeutic potential of sGC stimulators in mitigating heart failure through antioxidant effects.

## Key findings

- sGC stimulators increased antioxidant proteins like SOD1 and GSTM2 in heart tissue.
- Treatment reduced collagen deposition despite upregulating fibrosis-related markers like TGF-β.
- Untreated rats with advanced heart failure died before the study's end, highlighting disease severity.

## Abstract

Heart failure (HF) is a leading cause of morbidity and mortality, often driven by prolonged exposure to pathological stimuli such as pressure and volume overload. These factors contribute to excessive oxidative stress, adverse cardiac remodeling, and dysregulation of the nitric oxide‐soluble guanylate cyclase‐cyclic guanosine monophosphate (NO‐sGC‐cGMP) signaling pathway. Given the urgent need for effective treatments, this study investigated the potential of sGC stimulators to mitigate HF progression. We utilized male hypertensive Ren‐2 transgenic (TGR) rats and a volume‐overload HF model induced by an aortocaval fistula (ACF). Rats received the sGC stimulator BAY 41–8543 (3 mg/kg/day) for 30 weeks, while normotensive Hannover Sprague–Dawley rats served as controls. At the study endpoint (40 weeks of age), left ventricular tissue was analyzed using mass spectrometry, Western blotting, and histological assessment. TGR rats treated with sGC stimulators exhibited a significant increase in key antioxidant proteins (SOD1, CH10, ACSF2, NDUS1, DHE3, GSTM2, and PCCA), suggesting enhanced resistance to oxidative stress. However, sGC stimulator treatment also upregulated extracellular matrix remodeling markers (MMP‐2, TGF‐β, and SMAD2/3), which are typically associated with fibrosis. Despite this, Masson's trichrome staining revealed reduced collagen deposition in both TGR and TGR‐ACF rats receiving sGC stimulators. Notably, all untreated TGR‐ACF rats succumbed before the study endpoint, preventing direct assessment of sGC stimulator effects in advanced HF. These findings highlight the therapeutic potential of sGC stimulators in HF, particularly through their antioxidant effects. However, their concurrent influence on fibrosis warrants further investigation to optimize treatment strategies.