Pompeu Fabra University (UPF) and the Royal Veterinary College of London have worked together on a pioneering project worldwide to generate 3D reconstructions of the hearts of different animals and simulations of their blood flow using advanced computational techniques to date only applied to humans. So far, 3D images of cats' hearts have been generated, but soon the same will be done for dogs, pigs and sheep.
The project focuses on reconstructing the animals' left atrium, the part of the heart where thrombi (or blood clots) that can lead to a heart attack occur. By studying these reconstructions and comparing them with the existing ones of the human heart, it is hoped useful conclusions may be drawn to prevent thrombi both in humans and in animals.
Computational tools will enable studying the heart of different species and reduce direct experiments on animals
Moreover, as 3D reconstructions of the left atria of the different species become available, "it will be possible to study this part of the heart using computational methods and reduce the need to experiment directly on animals" – explains Andy L. Olivares (UPF), one of the researchers involved in the project.
The first study resulting from this project, dedicated to the left atrium of cats, has been published recently in Scientific Reports (Nature). The research team is mainly made up of researchers from the Physense group of the BCN MedTech Research Unit of the UPF Department of Engineering and the Cardiology Service of the Royal Veterinary College in London. Óscar Cámara (Physense, UPF) and Virginia Luis Fuentes (Cardiology Service of the Royal Veterinary College) are the principal co-investigators. Other co-authors of the study are linked to the Sant Joan de Déu Research Institute (IRSJD), Great Ormond Street Hospital for Children (NHS Foundation Trust) in London, and the Institute of Cardiovascular Science at University College London.
Why start studying cats' hearts?
Cats' heart tissue has particularly interesting characteristics to ascertain the relationship between heart morphology and thrombi, which, to date, has scarcely been analysed in medicine. In the case of the human heart, most of the existing studies focus on the relationship between clots and the most common type of arrhythmia, atrial fibrillation. The alterations of the movements of the heart muscle caused by arrhythmias cause the blood to be retained in a specific area of the left atrium of the heart where it should not accumulate, the left atrial appendage, which increases the risk of a thrombus.
Conversely, there are still some unknown factors concerning the relationship between the shape of the human heart and the risk of clotting. Precisely, in the case of cats, clots are due solely to heart morphology and the blood flow within, because they do not suffer arrhythmias. Therefore, with felines, the relationship can be analysed between thrombi and heart morphology without interference from arrhythmias. In other words, the first two factors can be isolated from the third.
This study examined the morphology of the left atrium and the blood flow characteristics (or haemodynamics) of 24 cats, 8 healthy (control group) and 16 with different cardiac pathologies. From medical images of the cats' hearts provided by veterinary clinics, 3D reconstructions of their left atria were generated using advanced computational techniques.
The larger the left atrium of the heart, the greater the risk of blood clots, a pattern shared by cats and humans
The recently published study associates some morphological features of cats' hearts with some pathologies. 3D heart reconstruction has shown that felines with a larger left atrium and a larger and bigger left atrial appendage are more at risk of clotting. The risk of thrombi is also increased if the blood circulates more slowly inside or if the left atrial appendage is more curved, which forces the blood to zigzag more in order to circulate. The left atrial appendage also has trabeculae (or lobes) and, if numerous, they can also stop blood flow and lead to the formation of clots.
The results suggest that the heart of felines behaves in a similar way to that of humans, since previous studies on the human left atrium had reached similar conclusions. However, more studies will need to be conducted with more feline samples to examine their heart behaviour in more detail.
New tools to prevent thrombi in people and animals
The same research team also plans to examine the left atrium of dogs, pigs and sheep in the near future. In short, they propose carrying out a cross-sectional study of different species to determine which hearts are most similar to the human heart and to provide new tools for diagnosing and preventing thrombi in the medical and veterinary fields.
Reference article:
Pons, MI, Olivares, AL, Mill, J. et al. Cardiomyopathy and thrombogenesis in cats through left atrial morphological and fluid dynamics analysis. Sci Rep 15, 12263 (2025). https://doi.org/10.1038/s41598-025-96245-7
