Can hydrogen gas protect the heart during bypass surgery?

This rat study suggests yes - 4% hydrogen gas significantly protected blood vessel linings during bypass surgery. The protective effects reduced inflammation and oxidative damage to levels similar to healthy controls.

How does hydrogen gas reduce damage during heart surgery?

Hydrogen appears to work through its anti-inflammatory and antioxidant properties. It reduced inflammatory proteins and oxidative stress markers that typically increase during bypass surgery.

What concentration of hydrogen gas was most effective?

Four percent hydrogen gas was significantly more protective than 2% hydrogen. The higher concentration better preserved blood vessel thickness and reduced damage markers.

Is hydrogen gas therapy safe during surgery?

In this rat study, hydrogen gas appeared safe with no adverse effects reported. However, human clinical trials would be needed to establish safety and effectiveness in patients.

What is the endothelial glycocalyx and why does it matter?

The endothelial glycocalyx is a protective gel-like layer lining blood vessels. When damaged during surgery, it can lead to inflammation, blood clotting problems, and poor circulation throughout the body.

Hydrogen Gas Protects Heart Blood Vessels During Bypass Surgery

Authors: Hiroki Iwata, Takasumi Katoh, Sang Kien Truong, Tsunehisa Sato, Shingo Kawashima, Soichiro Mimuro, Yoshiki Nakajima
Journal: PLoS One
Year: 2023
DOI: 10.1371/journal.pone.0295862
Study Type: Rat
Outcome: Positive
Peer Reviewed: Yes
Country: Japan
Health Condition: Cardiovascular Disease
Body System: Cardiovascular

TL;DR

Breathing in hydrogen gas during and after heart-lung machine use can protect blood vessel linings in rats from damage and reduce inflammation.

Key Finding

Rats treated with 4% hydrogen gas during cardiopulmonary bypass showed significantly less damage to their blood vessel linings and lower inflammatory markers compared to untreated rats, with protective effects appearing to be dose-dependent.

Summary

This rat study tested whether hydrogen gas could protect blood vessel linings from damage caused by cardiopulmonary bypass (a heart-lung machine used during surgery). Rats were given either no hydrogen, 2% hydrogen, or 4% hydrogen gas during and after a 90-minute bypass procedure. The 4% hydrogen group showed thicker blood vessel linings and lower levels of inflammatory markers and oxidative stress (cellular damage from unstable molecules) compared to the control group, with results similar to rats that didn't undergo bypass at all.

Practical Takeaway

This is early animal evidence suggesting hydrogen gas may help protect blood vessels during heart surgery, but it comes from rat studies only and cannot yet be applied to humans. Much more research, including human trials, would be needed before any clinical recommendations could be made. The dose-dependent effect (4% worked better than 2%) is noted but requires further investigation.

Abstract

Cardiopulmonary bypass (CPB) causes systemic inflammation and endothelial glycocalyx damage. Hydrogen has anti-oxidant and anti-inflammatory properties; therefore, we hypothesized that hydrogen would alleviate endothelial glycocalyx damage caused by CPB. Twenty-eight male Sprague-Dawley rats were randomly divided into four groups (n = 7 per group), as follows: sham, control, 2% hydrogen, and 4% hydrogen. The rats were subjected to 90 minutes of partial CPB followed by 120 minutes of observation. In the hydrogen groups, hydrogen was administered via the ventilator and artificial lung during CPB, and via the ventilator for 60 minutes after CPB. After observation, blood collection, lung extraction, and perfusion fixation were performed, and the heart, lung, and brain endothelial glycocalyx thickness was measured by electron microscopy. The serum syndecan-1 concentration, a glycocalyx component, in the 4% hydrogen group (5.7 ± 4.4 pg/mL) was lower than in the control (19.5 ± 6.6 pg/mL) and 2% hydrogen (19.8 ± 5.0 pg/mL) groups (P < 0.001 for each), but it was not significantly different from the sham group (6.2 ± 4.0 pg/mL, P = 0.999). The endothelial glycocalyces of the heart and lung in the 4% hydrogen group were thicker than in the control group. The 4% hydrogen group had lower inflammatory cytokine concentrations (interleukin-1β and tumor necrosis factor-α) in serum and lung tissue, as well as a lower serum malondialdehyde concentration, than the control group. The 2% hydrogen group showed no significant difference in the serum syndecan-1 concentration compared with the control group. However, non-significant decreases in serum and lung tissue inflammatory cytokine concentrations, as well as in serum malondialdehyde concentration, were observed. Administration of 4% hydrogen via artificial and autologous lungs attenuated endothelial glycocalyx damage caused by partial CPB in rats, which might be mediated by the anti-inflammatory and anti-oxidant properties of hydrogen.