Google applied artificial intelligence to predict something deadly serious: The likelihood that a patient will suffer a heart attack or stroke. The researchers made these determinations by examining images of the patient’s retina.
Google, which is presented its findings in Nature Biomedical Engineering, an online medical journal, says that such a method is as accurate as predicting cardiovascular disease through more invasive measures that involve sticking a needle in a patient’s arm.
At the same time, Google cautions that more research needs to be done.
According to the company, medical researchers have previously shown some correlation between retinal vessels and the risk of a major cardiovascular episode. Using the retinal image, Google says it was able to quantify this association and 70% of the time accurately predict which patient within five years would experience a heart attack or other major cardiovascular event, and which patient would not. Those results were in line with testing methods that require blood be drawn to measure a patient’s cholesterol.
Google used models based on data from 284,335 patients and validated on two independent data sets of 12,026 and 999 patients.
Lily Peng, a doctor and lead researcher on the project, says Google was a bit surprised by the results. Her team had been working on predicting eye disease, and then expanded the exercise by asking the model to predict from the image whether the person was a smoker or what their blood pressure was. Taking it further to predicting the factors that put a person at risk of a heart attack or stroke was an offshoot of the original research.
Google’s technique generated a “heatmap,” or graphical representation of data that revealed which pixels in an image were the most important for predicting a specific risk factor. For example, Google’s algorithm paid more attention to blood vessels for making predictions about blood pressure.
“Pattern recognition and making use of images is one of the best areas for AI right now, says Harlan M. Krumholz, a professor of medicine (cardiology) and director of Yale’s Center for Outcomes Research and Evaluation, who considers the research a proof of concept.
Should further research pan out over time, physicians, as part of routine health check-ups, might study such retinal images to help assess and manage patients’ health risks.
