An innovative new patch limits heart muscle damage after a heart attack.
A heart attack occurs when the blood flow that provides the heart muscle with oxygen is significantly reduced or blocked.
The heart muscle is injured in the process, and the amount of damage usually depends on the size of the area supplied by the blocked artery.
It can take about 8 weeks for the heart muscle to heal. Despite the damage, the rest of the heart has to keep on pumping blood.
Scar tissue may form in the injured area and have an impact on the amount of blood that the heart is able to pump.
Most people who survive a heart attack have some degree of coronary artery disease. This occurs when arteries become hardened and narrowed. Usually, survivors have to make crucial lifestyle changes and may have to take medication to prevent a future heart attack.
According to the Centers for Disease Control and Prevention (CDC), more than 700,000 people in the United States have a heart attack every year. Of these, more than 500,000 experience their first heart attack and about 200,000 have already had one.
Testing a new type of adhesive heart patch
Scientists at Brown University in Providence, RI, Fudan University in Shanghai, China, and Soochow University in Suzhou, China have collaborated to create and test a new type of adhesive heart patch on rats.
The study was an interdisciplinary effort among researchers in computer modeling and mechanics, material scientists, and cardiology. The scientists published their findings in the journal Nature Biomedical Engineering.
The scientists created this adhesive patch using a water-based hydrogel material and developed it using computer simulations. The patch can sit directly on the heart, and the results of the study show that it may help limit the muscle damage that often occurs after a heart attack.
"The idea here," explains study co-author Prof. Huajian Gao, from Brown University, "is to provide mechanical support for damaged tissue, which hopefully gives it a chance to heal."
Prof. Gao goes on to say that past studies had shown that mechanical patches could be effective, but no research had attempted to identify the "optimum mechanical properties." Getting those properties right is crucial to ensuring that the patch can work properly.
"If the material is too hard or stiff," he adds, "then you could confine the movement of the heart so that it can't expand to the volume it needs to. But, if the material is too soft, then it won't provide enough support. So, we needed some mechanical principles to guide us."
Creating right mechanical properties is key
The researchers developed a computer model focused on two key components, one of which was the expanding and contracting of the heart and the impact the patch had on these functions.
The other was to model the injuries that occur after a heart attack. In this way, the team could look at how much mechanical support would be necessary to limit the damage.
Following the results of the computer model, the researchers — led by Prof. Lei Yang, of Soochow University — created a hydrogel material using food-sourced starch. This material is inexpensive, easy to make, and viscoelastic, which means that "it combines fluid and solid properties."
The study in rats showed that this new type of adhesive patch was effective in reducing muscle damage after a heart attack.
"[It] maintained a better cardiac output and thus greatly reduced the overload of those remaining cardiomyocytes and adverse cardiac remodeling," says study co-author Ning Sun, a cardiology researcher at Fudan University.
Their research found that the patch can reduce cell death, the accumulation of scar tissue, and oxidative stress. The researchers believe that more testing is required, but the results are promising.
"It remains to be seen if it will work in humans, but it's very promising."
Prof. Huajian Gao