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MedStar Health Research Institute scholars analyzed data from an international collaboration of researchers to develop new detailed standards for echocardiograms.
What is a “normal” echocardiogram (cardiac ultrasound)? Thanks to a global collaboration, the answer to that question is now much more nuanced. The World Alliance Societies of Echocardiography (WASE) Normal Values Study measured people's hearts from six continents, refuting the idea that the size and function of a white heart is similar to that of others around the world, and therefore should be used to create standard nor guidelines for all patients around the world.
An echocardiogram, or echo, is an ultrasound of the heart and nearby blood vessels. A small probe sends out high-frequency sound waves that create echoes when they bounce off internal body parts, resulting in an image doctors can analyze. Echo is the most common way of imaging the heart.
To understand whether a patient’s heart is functioning properly, echo measurements are compared to “normal” standards defined by the American Society of Echocardiography. The previous standards were based on clinical trial data that almost exclusively included white people from the U.S. and Europe—and failed to capture functional distinctions between men and women or in the hearts of people from diverse races or ages.
This enormous limitation means that, for decades, echocardiography standards were inaccurate for most people worldwide. While many differences are subtle, some may significantly change a patient’s course of care based on what is normal for their gender and ethnicity.
The WASE international collaborative, which was sponsored by the American Society of Echocardiography, launched The Normal Values Study in 2016 to help correct this data deficit.
Global collaboration for worldwide data.
To gather data for The Normal Values Study, experts from 15 countries examined echoes from 2,000 healthy participants from six continents, spanning ages throughout adulthood age groups and equally distributed among sex and nationality. Using state of the art technology and protocols, this effort resulted in consistent data used to determine appropriate “normal” ranges for ethnically and geographically diverse patients. The global data was analyzed at MedStar Health Research Institute and the University of Chicago.
The resulting database allows us to compare heart structure and function among people with varied backgrounds. The data have formed the foundation of more than 15 scholarly papers that describe distinct aspects of the heart and define normal values for its structures.
For instance, we now understand that the hearts of Black and white people are of similar size and volume, while Asian and Mexican people often have smaller hearts. This sort of knowledge from the Normal Values Study leads scientists toward a future of personalized echocardiography—context is critical to making an accurate diagnosis. By acknowledging that human hearts are not all the same, providers can accurately evaluate each patient’s cardiovascular health.
Digging deeper for more personalization.
The Normal Values Study is complete, but there’s only so much you can learn from studying 2,000 people. For example, it would be an overstatement to assume people of all ethnicities in China or India, for example, have the same heart size and function.
To get closer to personalization, we must understand the role of ethnicity in cardiovascular health standards. One way to accomplish this is with a much larger global study. Another is for groups of local investigators to take up the work, learning more about their specific populations.
The collective effort of WASE volunteer experts worldwide enabled The Normal Values Study to answer questions no single investigator could have addressed. Since the Study began in 2016, this new model of echocardiography research has been put into action twice.
Early in the COVID-19 Pandemic, WASE investigators worldwide came together to efficiently understand how COVID was impacting the hearts of patients with acute COVID infection. A third WASE study is now underway, examining patients with a specific heart disease called cardiac amyloidosis.
Personalized medicine is better medicine. The more we understand expected differences in normal heart function, the more valuable echocardiograms will be. And the more experts worldwide can collaborate on research, the better our understanding of the human body and its endless variation will become.