Protein Marker ST2 and Myocardial Mapping of Cosmonauts After Spaceflight

<jats:p> <jats:bold>INTRODUCTION:</jats:bold> Cardiac remodeling can occur during spaceflights. This research aimed to study the relationship between the ST2 plasmatic biomarker and some cardiac MRI parameters of cosmonauts after 6- or 12-mo spaceflights. </jats:p> <jats:p> <jats:bold>METHODS:</jats:bold> Venous blood for ST2 level assessment from nine Russian cosmonauts was collected 30 d before launch and on the first and seventh days after landing. The cardiac MRI sessions with T1- and T2-mapping of the heart were conducted before launch and on the fourth day after landing. </jats:p> <jats:p> <jats:bold>RESULTS:</jats:bold> Variance analysis of the ST2 levels revealed a significant increase in all cosmonauts on the first day after spaceflight ( <jats:italic>P</jats:italic> = 0.014). On the seventh day after landing the ST2 level decreased, approaching background values. On the fourth day after landing, the MRI mapping showed structural changes in the myocardial segments that corresponded to the g-load vectors during landing. </jats:p> <jats:p> <jats:bold>DISCUSSION:</jats:bold> Our findings indicate a transient myocardial over-distention upon landing, as well as an increased risk of cardiac fibrosis after spaceflight. </jats:p> <jats:p> <jats:bold> Goncharova AG, Pastushkova LH, Luchitskaya ES, Kashirina DN, Nosovsky AM, Goncharov IN, Kireev KS, Larina IM. <jats:italic>Protein marker ST2 and myocardial mapping of cosmonauts after spaceflight</jats:italic> . Aerosp Med Hum Perform. 2026; 97(4):243–248. </jats:bold> </jats:p>