Replicas of diseased hearts: Scientists have built highly detailed virtual copies of diseased hearts and used them to test treatment before operating on real patients, offering an early glimpse of how digital “twins” could change care for dangerous heart-rhythm disorders.
In one of the first clinical trials of its kind, researchers at Johns Hopkins University used the technology to help treat patients with ventricular tachycardia, a hard-to-manage arrhythmia that can trigger sudden cardiac arrest. The condition is linked to roughly 300,000 deaths each year in the United States.
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The trial was small and meant as an early step. The US Food and Drug Administration cleared the digital twin system to guide treatment in just 10 patients, so much larger studies will be needed before doctors know how widely it can help. Still, the findings, published Wednesday in The New England Journal of Medicine, add momentum to a growing effort to bring a tool long used in aerospace and engineering into everyday medicine.
Dr Jeffrey Goldberger, a heart specialist at the University of Miami who was not involved in the research, said the results reflect what many in the field had hoped digital heart modelling could eventually achieve. He noted that early forms of the idea were being explored years ago, but the new work shows how much more precise the technology has become.
Doctors have used 3D models for years, including physical replicas and computer simulations, to better understand disease and rehearse procedures. What makes these new models different, according to Johns Hopkins biomedical engineer Natalia Trayanova, is that they are designed to predict how a specific patient’s organ will respond to treatment. Her team builds the interactive models using advanced MRI scans and other patient-specific data.
The idea, she said, is to test a treatment on the virtual heart first. If it works in the model, doctors can move forward with more confidence. If it reveals another possible rhythm problem, they can adjust the plan before the actual procedure.
The heart depends on electrical signals to maintain a steady beat. In ventricular tachycardia, those signals become disrupted in the lower chambers, called the ventricles, causing the heart to beat so fast that it cannot pump blood properly.
Medicines can sometimes control the problem, but one of the main treatments is catheter ablation. In that procedure, doctors guide thin tubes into the heart and burn small areas of tissue that are causing the faulty electrical signals. The challenge is that the process often involves a degree of trial and error, with patients spending hours under anaesthesia while doctors identify the right spots to target. Repeat procedures are not unusual, and many patients also rely on implanted defibrillators as a safeguard.
That is where the digital twin comes in. On a computer screen, the patient’s virtual ventricles show how electrical waves travel through healthy tissue before getting trapped around scarred or damaged areas. The pattern can resemble a storm circling in place, helping doctors see where the abnormal rhythm is likely to begin and continue.
The software identifies the regions most responsible for sustaining the arrhythmia. Researchers can then perform a virtual ablation inside the model to see whether the abnormal rhythm stops or whether another one appears. That allows the care team to refine the strategy before entering the operating room.
For the trial, Trayanova’s team created personalised ablation targets for all 10 patients. Cardiologists then transferred those targets into their existing mapping systems and used them to guide treatment instead of searching on their own during the procedure.
More than a year later, eight of the 10 patients had not experienced any further arrhythmias. The other two had only one short episode each while recovering. According to the researchers, this compares favourably with the roughly 60% success rate usually seen with standard treatment. Most of the patients were also able to stop taking anti-arrhythmia drugs, with only two continuing medication.
Dr. Jonathan Chrispin, a Johns Hopkins cardiologist and lead author of the study, said one of the biggest advantages may be precision. By focusing only on the areas most likely to be driving the rhythm problem, doctors may be able to destroy less heart tissue and make procedures shorter, safer and more effective.
The Hopkins team now plans to test the approach in a larger, multi-centre study. Researchers have also started exploring whether similar digital twin models can help treat atrial fibrillation, a much more common irregular heartbeat. Beyond cardiology, other scientists are investigating how the same concept might be used in cancer treatment.