3D printed heart replicates a pumping heart

3D printed heart replicates a pumping heart, bioengineers led by a team from the Massachusetts Institute of Technology described how they printed soft models of individual patients’ hearts that could pump just like their real hearts and used cardiovascular data from individual patients in a paper that was published in Science Robotics. These 3D-printed hearts were able to mimic the function of an actual human heart.

Aortic stenosis, a heart valve issue that affects up to a quarter of adults over 65, has no known therapy solutions. The damaged valve may only be modified by implanting a prosthetic device that is appropriate for the patient’s anatomy and heart’s pumping function. While the majority of instances are simple, others are more complicated. Cardiologists could better fit patients’ hearts and understand how their hearts function by using 3D-printed hearts.

First author Luca Rosalia believes that every individual heart is unique in its own way. Massive variances exist, particularly when patients are ill. This approach will help replicate the shape and function of a patient’s heart in both health and sickness.

When the breadth of the aortic valve falls below 1 square centimeter, severe aortic stenosis that necessitates intervention takes place. Transcatheter aortic valve replacement is a minimally invasive treatment that is frequently used to treat patients over the age of 65. Cardiologists do TAVR by inserting either the Evolut R from Medtronic or the SAPIEN 3 from Edwards Lifesciences into the aortic valve. The prosthesis grows and fuses with the tissue, restoring the heart’s ability to pump blood efficiently.

Nish Harshadkumar Patel, an interventional cardiologist at the Miami Cardiac & Vascular Institute of Baptist Health South Florida, stated that the decision to perform TAVR is fairly simple in patients with the classic form of severe aortic stenosis, where the left ventricle ejection fraction is less than 50%. According to him, in situations like these, 3D modeling would be really valuable in understanding the biomechanical component of that valve and how it reacts in different flow dynamics.

The Roche lab set out to develop soft models that were anatomically and functionally typical of certain patients to determine whether they might provide a remedy using 3D-printed hearts. They created digital 3D representations by combining the CT data from 15 individuals with aortic stenosis. The stretchiness of the elastic-plastic resin used to print the actual 3D models of the heart muscle was designed to imitate the heart muscle.

The scientists wrapped the participants in sleeves resembling blood pressure cuffs to get their hearts to beat. The four inflatable compartments on each sleeve were fashioned to closely resemble the form of the wearer’s heart. The researchers could fine-tune the pumping motion such that it resembled the patient’s actual heart by adjusting the rate of contraction for each pocket separately. 

The motion was controlled by a robotic air pump. The models’ working hearts were recorded during echocardiograms, which the researchers then compared to echocardiograms taken from actual patients. They discovered that the simulations accurately captured the pressure and blood flow experienced by the patients, including those whose hearts had particular pumping strategies because of tissue remodeling brought on by aortic stenosis.

The next step was for the researchers to see if they could similarly mimic the impact of TAVR on patients’ hearts. Evolut R or SAPIEN 3 prostheses were implanted into the models, and the pumping activity was then recorded and compared to post-implantation outcomes from real patients. The enhanced flow dynamics of the patients were once more mapped by the models.

The scientists completed their investigation by testing how the models may be used in the real world by fitting patient hearts with various prosthetic limb sizes to determine any possible issues that might arise from a mismatch. The models’ measurements confirmed that undersized implants will actually result in the problems brought on by the pumping dynamics of a condition known as paravalvular leak and regurgitation.