Atrial fibrillation is one of the most common kinds of arrhythmia, causing the heart not to contract properly in order to pump the blood, which can lead to the formation of thrombi (blood clots) and the consequent associated risks (heart attack, stroke...). Normally, patients with atrial fibrillation take anticoagulants, but the dose must be adjusted and kept as low as possible, because these drugs have negative side effects, especially as they increase the risk of heavy bleeding. If bleeding is internal, it can lead to hemorrhagic strokes, embolisms or abdominal bleeding.
An alternative to anticoagulants, or at least to reduce the required dose, is the installation of a specific device in the left atrial appendage of the heart. It is precisely in this part of the heart that blood clots can form when the heart tissue does not contract properly. The device blocks the passage of blood to the left atrial appendage to prevent thrombi from occurring. But it must be placed precisely, adjusting it to the anatomy of each patient's heart. In addition, after the operation, the patient's condition must continue to be monitored to calculate the extent to which the dose of anticoagulants can be reduced at any given time.
A dual purpose: to adjust the position of the device installed in the patient's heart to prevent thrombi, and the dose of anticoagulants
Combining these and other factors that affect the success of the operation and the patient's evolution is highly complex. But recently, UPF scientists have created a new pioneering computational model that enables integrally analysing all these factors using medical images provided by Hospital Clínic de Barcelona. At UPF, the principal investigator of the study is Oscar Camara, of the PhySense research group of the BCN MedTech Unit at the UPF Department of Engineering , while at Hospital Clínic de Barcelona, Dr. Xavier Freixa is leading the study.
The model is based on a 3D reconstruction of the heart of each patient, resorting to a computerized tomography (scan) of the left atrium and can be of great help to medical professionals who perform this surgical intervention or monitor patients. This is so much so that the renowned clinical journal JACC: Case Reports, published by the American College of Cardiology, has published the study which describes this new computational model and the (proof of concept) test that has been successfully conducted on a patient with atrial fibrillation. At the international level, this is the first time a medical journal has published a study that deals with a computational model for this purpose.
The main author of the article is Maria Segarra, of the PhySense research group at UPF, who highlights its potential: "the model can be of great help to doctors to establish the optimal position of the device for each patient, which is fundamental in the preoperative phase, and the dose of anticoagulants required after the intervention, which is essential for the postoperative period".
For Dr. Xavier Freixa, of the Cardiology Service of Hospital Clínic de Barcelona, "this model allows us far more precisely to anticipate how to intervene in each patient and how to adjust anticoagulant treatment after the intervention, reducing risks and improving safety".
It should be noted that anticoagulants cannot be suddenly withdrawn straight after the device is installed. On the one hand, the device remains a foreign body that requires a certain amount of time to adapt. In fact, thrombi associated with the installation of the device can occur precisely due to this. However, once the device has been successfully inserted, the patient can gradually reduce the dose of anticoagulants and even stop taking them. On the other hand, without the operation, patients are required to take them indefinitely.
The first test of the model passed successfully
The researchers have conducted this proof of concept study on a 78-year-old patient with atrial fibrillation and a history of stroke. The characteristics of this case thus made the operation to install the device in the left atrial appendage highly recommendable with a view to minimizing the dose of anticoagulants to treat arrhythmia. The new computational model was used to determine the optimal position for the device and the dose of anticoagulant needed during the first months after the intervention.
Great medical potential
The proof of concept and the case in hand endorses the effectiveness of the model for which there are plans to test it on a larger number of patients. Given its potential in the clinical setting, this computational model can be of great help to healthcare professionals who intervene in the preoperative, operative and postoperative stages of patients with atrial fibrillation who require having the device installed in their left atrial appendage.
Reference article:
Maria Segarra-Queralt, Marc Molla, Manal Barrouhou, Andy L. Olivares, Carlos Albors, Gabriel Bernardino, Ander Regueiro, Jordi Mill, Òscar Càmara, Xavier Freixa, The Role of Anticoagulants After Left Atrial Appendage Occlusion, JACC: Case Reports, Volume 30, Issue 40, 2025, https://doi.org/10.1016/j.jaccas.2025.105838 .
