New retinal test can predict heart attack
Combining information about the pattern of blood vessels in the retina with genetic data may allow accurate prediction of an individual’s risk of coronary artery disease (CAD) and its potentially fatal outcome, myocardial infarction (MI), commonly known as heart attack.
The discovery could lead to a simple screening process in which the risk of myocardial infarction could be calculated when a person undergoes a routine eye test, the researchers said at the annual conference of the European Society of Human Genetics.
“We already knew that variations in the retinal vasculature could offer information about our health. Since retinal imaging is a non-invasive technique, we decided to investigate the health benefits we could gain from these images. First, we studied the branching patterns of the retinal vasculature by calculating a measure called fractal dimension (Df) from data available in the United Kingdom Biobank (UKB). UKB includes demographic, epidemiological, clinical, imaging and genotyping data from over 500,000 participants across the UK. We found that lower Df, simplified vessel branching patterns, is related to CAD and therefore MI,” says Ms Ana Villaplana-Velasco, PhD student at the Usher and Roslin Institutes at the University of Edinburgh. , Edinburgh, United Kingdom.
The researchers then developed a model that could predict MI risk by studying UKB participants who had experienced an MI event after their retinal images were collected. The model included Df in addition to traditional clinical factors such as age, sex, systolic blood pressure, body mass index, and smoking status to estimate personalized myocardial infarction risk.
“Surprisingly, we found that our model was better able to classify participants as having low or high risk of myocardial infarction in UKB compared to established models that only include demographic data. The improvement of our model was even greater if we added a score related to the genetic propensity to develop IM,” said Ms. Villaplana-Velasco.
“We wondered if the Df-MI association was influenced by shared biology, so we looked at the genetics of Df and found nine genetic regions that drive retinal vascular branching patterns. Four of these regions are known to be involved in the genetics of cardiovascular diseases. “In particular, we discovered that these common genetic regions are involved in processes related to myocardial infarction severity and recovery.”
These findings may also be useful in identifying susceptibility to other diseases. Variations in retinal vascular pattern also reflect the development of other ocular and systemic diseases, such as diabetic retinopathy and stroke . The researchers believe it is possible that each condition may have a unique retinal variation profile.
“We would like to investigate this further, as well as perform a sex-specific analysis. We know that women with a higher risk of MI or CAD tend to have pronounced retinal vascular deviations compared to the male population. We would like to repeat our analysis separately in men and women to investigate whether a sex-specific model for MI completes a better risk classification,” says Ms. Villaplana-Velasco.
Although the researchers knew that variations in retinal vasculature were associated with an individual’s health status, their compelling results came as a surprise. “There have been multiple attempts to improve predictive models for CAD and MI risk by taking retinal vascular traits into account, but these did not show significant improvement compared to established models. In our case, we found that the clinical definition of myocardial infarction, the diagnostic codes that describe myocardial infarction events in medical records, is critical to the successful development of predictive models, supporting the need to develop robust definitions. of diseases in large studies such as UKB. Once we validated our definition of MI, we found that our model worked extremely well,” said Ms. Villaplana-Velasco.
In the future, a simple retinal exam may provide enough information to identify people at risk. The average age of a heart attack is 60 years, and the researchers found that their model achieved its best predictive performance more than five years before the heart attack event.
"Therefore, calculating an individualized MI risk for those over 50 years of age would seem appropriate," says Ms. Villaplan-Velasco. “This would allow doctors to suggest behaviors that could reduce risk, such as quitting smoking and maintaining normal cholesterol and blood pressure levels. “Our work shows once again the importance of comprehensive analysis of routinely collected data and its value in the further development of personalized medicine.”
Professor Alexandre Reymond, chair of the conference, said: "This study demonstrates the importance of implementing prevention now and how personalized health gives us the tools to do so."
Abstract C22.6: Decreased retinal vascular complexity is an early biomarker of myocardial infarction supported by a shared genetic control. https://2022.eshg.org/
