October 20, 2023

Unlocking the Secrets of Heart Shape: What Your Heart’s Form May Reveal About Your Health

Imagine this: a heart, not as we know it symbolically, but in its true form, beating rhythmically within the confines of your chest. It turns out that the shape of this vital organ may hold clues to your heart’s health that we never truly understood until now. A groundbreaking 2023 study, led by a team of researchers at Stanford Medicine, armed with the power of artificial intelligence, has unveiled surprising insights into the shape of the heart and its profound implications for our well-being.

For decades, medical professionals have known that a heart-shaped like the iconic Valentine’s Day symbol is not a sign of robust health. Instead, it signifies an organ under duress, struggling to fulfill its life-sustaining role. However, this insight typically comes after the onset of cardiac conditions. The researchers, led by the visionary Dr. Shoa Clarke, a preventive cardiologist at Stanford Medicine, sought to change this paradigm. They wanted to explore whether the shape of the heart could serve as an early indicator of cardiac problems, long before clinical diagnoses were made.

“Most people who practice cardiology are well aware that after someone develops heart disease, the heart will look more spherical,” said Dr. Clarke.

Their journey into the heart’s secrets led them to the intriguing concept of “sphericity,” or roundness. What if the shape of the heart could offer important health clues even before the appearance of symptoms? The researchers embarked on a mission to uncover the genetic underpinnings of various cardiac conditions, including heart arrhythmia (atrial fibrillation) and congestive heart failure.

Atrial fibrillation, characterized by erratic heart rhythms, and congestive heart failure, where the heart struggles to pump enough blood, are conditions that affect millions of lives worldwide. These conditions are often detected after they have taken hold, causing significant health challenges. But what if we could predict them earlier, potentially saving lives and improving outcomes?

Dr. Clarke and his colleague, Dr. David Ouyang from the Smidt Heart Institute of Cedars-Sinai, delved deep into the world of cardiac shapes after noticing a peculiar phenomenon in their clinical practice. They observed variations in heart shapes and morphology, even when traditional metrics appeared normal. This observation sparked their curiosity: Could the heart’s shape be a crucial predictive variable for heart health long before the manifestation of clinical symptoms?

To answer this question, they turned to artificial intelligence and the vast treasure trove of medical images from the UK Biobank. With nearly 40,000 healthy hearts as their canvas, they began their artistic exploration. Their focus was on the left ventricle, a core part of the heart responsible for its mechanical heavy lifting. The left ventricle is highly susceptible to damage, as it tirelessly pumps blood throughout the body and can change its shape over time, becoming more spherical.

Their journey unfolded in two phases. First, they analyzed the biobank data to establish a link between increased sphericity and the risk of developing cardiomyopathy, atrial fibrillation, or heart failure. Astonishingly, even a slight increase in roundness was associated with a 47% higher likelihood of developing these conditions within a decade.

Next, they peered into the genetic markers of both sphericity and these cardiac conditions, searching for a hidden connection. What they unearthed was groundbreaking. Intrinsic disease of the heart muscle, damage not caused by a heart attack, could trigger the heart to take on a spherical shape, even before any clinical signs of heart disease emerge.

In essence, increased sphericity could be a warning sign, an early identifier of individuals with underlying molecular and cellular abnormalities that place them at a heightened risk of developing severe heart conditions like cardiomyopathy and atrial fibrillation.

Imagine a future where the shape of your heart becomes a baseline detail collected during routine clinical examinations. Dr. Clarke envisions this possibility, stating, “We may start to see changes in the sphericity that are indicative of someone already going down that path of developing a heart problem.”

While the revelations about cardiac sphericity are undoubtedly fascinating, Dr. Clarke sees an even broader implication of their work. He emphasizes that current medical imaging, like the MRI scans they used, holds a wealth of untapped scientific clues that could drive a multitude of groundbreaking studies. He passionately declares, _”The main point I’m trying to make with this study is that there is information in current medical imaging that’s not being used.”

Dr. Clarke and Dr. Ouyang are not only passionate about biomedical science but also deeply committed to data science. They believe that while artificial intelligence holds immense potential, its true impact in the medical field is yet to be fully realized. Dr. Clarke points out, _”There is broad enthusiasm for using artificial intelligence, biobanks, and genomics to accelerate biomedical research, yet the number of practicing clinicians who have the technical skills to lead such research is still relatively small.”

However, their remarkable study is not without limitations. They note a lack of racial diversity within the UK Biobank, which can impact the generalizability of their findings. Dr. Clarke acknowledges this issue, emphasizing that diversity must remain a priority in large-scale biobanks to ensure equitable representation. He remarks, _”For imaging studies, this was a very large number, but one problem with it being the only source of such large-scale data is that it lacks diversity.”

Moreover, their data was collected as part of a study, not in a clinical setting. This approach minimizes bias towards individuals seeking medical attention due to existing health problems. It’s essential to consider these nuances when interpreting their findings.

Crucially, Dr. Clarke urges caution when interpreting the significance of increased sphericity. While it may signal a higher risk of developing cardiac conditions, it is not a guarantee of future health issues. In fact, the majority of individuals with increased sphericity in their study cohort did not develop clinical disease during their follow-up period, which extended for up to a decade. He underscores, _”It’s not a guarantee that having high sphericity means you will have some clinical manifestation. It’s just a marker for people who are at higher risk. Other factors could be at play.”

So, what lies on the horizon for this exciting avenue of research? Dr. Clarke envisions exploring a wide array of heart conditions beyond cardiomyopathy, encompassing rhythm disturbances, valve diseases, and vascular diseases like coronary artery disease. The possibilities are endless, and the world of medical imaging holds untapped potential for uncovering new insights into heart health.

As Dr. Ouyang aptly puts it, “There’s a lot more information available than what physicians are currently using.”

In closing, Dr. Clarke and Dr. Ouyang leave us with a profound reminder: Just as we’ve long known that a bigger heart isn’t always better, their pioneering research reveals that a more spherical heart may also not be better. The heart, in all its complexity, continues to captivate the minds of researchers, offering new vistas of understanding and the promise of better cardiovascular health for all.

This groundbreaking study was made possible by generous funding from the National Institutes of Health, underscoring the importance of collaborative efforts in advancing our knowledge of the human heart and its intricacies.