Prolonged exposure to microgravity leads to progressive cardiovascular deconditioning, a well-known phenomenon in space missions. In the absence of normal gravitational forces, the heart and blood vessels undergo functional and structural changes that can significantly reduce astronauts’ exercise capacity, measured in particular through maximal aerobic power (VO2max).
A new study published in npj Microgravity, Nature group— featuring contributions from Sarah Solbiati, Riccardo Bedandi, and Enrico Caiani from the D-Hygea Lab, Department of Electronics, Information and Bioengineering – Politecnico di Milano — now suggests a way to measure such decline using non-invasive and easily applicable tools.
The researchers retrospectively analysed data collected, thanks to multiple funding from the Italian Space Agency, during six head-down tilt bed rest campaigns, a ground-based model that simulates the effects of cardiovascular deconditioning due to microgravity. By combining information from 24-hour Holter ECG recordings, performed both before and at the end of the bed rest, they developed a Machine Learning model capable of estimating maximal aerobic power decline from multiple features of the ECG and from baseline VO2max.
The results showed strong predictive accuracy, in particular in the evaluation of a still preserved VO2max, indicating that such approach could enable more frequent monitoring of cardiovascular deconditioning not only in space environments (where performing the VO2max test is complicate) but also in clinical settings, thus suggesting to avoid the test when not strictly needed, thus increasing test diagnostic appropriateness and cost savings for the healthcare system. This advancement opens concrete prospects for both astronauts’ health monitoring as well as for new medical-diagnostic applications on Earth.