A new study from MIT researchers has discovered why an imbalance occurs between the left and right ventricles in patients receiving mechanical pump assistance after a heart attack. The researchers have also developed a test that can determine whether this dysfunction will occur in a particular patient, giving doctors more confidence when deciding whether to use the pumps.
Cardiogenic shock, a life-threatening condition caused by a severe heart attack, affects about 50,000 people in the United States each year. Many of these patients receive assistance from mechanical pumps known as ventricular assist devices (VADs) to help their hearts pump blood until they recover enough to function on their own. However, in nearly 43% of these patients, the use of VADs leads to an imbalance between the left and right ventricles, which can be dangerous.
The researchers wanted to understand why this imbalance occurs and develop a way for doctors to predict whether it will happen in a specific patient. By having this information, doctors can implant another VAD to support the right ventricle if needed.
To study this, the researchers used an animal model of heart failure and implanted a VAD in the left ventricle of each animal. They then analyzed various metrics of heart function as they increased and decreased the pumping speed of the device. They found that the most important factor in determining the response of the right ventricle to the VAD was the ability of the pulmonary vascular system to adapt to changes in blood volume and flow induced by the device.
The researchers developed a test that measures the compliance and adaptability of the pulmonary vascular system, which can predict how a patient will respond to left ventricle assistance. Using a dataset of eight patients who had received a left VAD, they found that these measurements correlated with the right heart state, validating the findings from the animal study.
Doctors would need to implant the VAD as usual and measure the compliance of the pulmonary vascular system while increasing the device’s speed to perform the test. The researchers hope to expand on these findings with additional animal studies and collaborate with device manufacturers to run clinical studies in the future.
Currently, there are few metrics available to predict device tolerance, and doctors rely on experiential evidence. This new understanding could help physicians determine which patients will be intolerant to device support and provide guidance on the best treatment based on the right heart state.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
