For people who undergo surgery to implant a left heart pump, the risk of subsequent right heart failure is high: 15 to 30 percent. But the large number of factors that contribute to an individual’s risk of right heart failure make personalized risk prediction “exceptionally difficult,” says Iosif Taleb, M.D., currently a cardiology fellow at University of California, San Diego and first author on the study. Taleb helped develop the risk calculator during his clinical research fellowship at U of U Health. 

“Each patient is unique with different health conditions and heart characteristics,” Taleb says. “Heart pumps also have specific traits, and the combination of these factors makes predictions tough.”

Stavros Drakos, M.D., Ph.D., professor of cardiology at U of U Health and senior author on the publication describing the study, says that “there have been efforts in the past to predict which patients will get a heart pump [also called a left ventricular assist device, or LVAD] and will not do well, but they didn’t perform well in the real world.” Even models that seemed to predict outcomes in one hospital often failed to give accurate predictions at another.

Aiming to develop a more accurate and broadly usable risk calculator, the researchers used patient data from 1,125 people across six health centers, including U of U Health. Taking into account variables ranging from pre-existing health conditions to medications and demographic information, they used machine learning to generate and test many models of risk and find the one that best described patients’ health outcomes.

Their model identified several variables that are especially useful when predicting whether a patient will develop right heart failure (RVF), such as whether patients needed additional forms of heart support before their initial surgery in order to better prepare them and lead to better outcomes. The researchers used these factors to develop an easy-to-use online calculator that determines a patient’s percent risk of right heart failure after surgery.

The new risk calculator, called STOP-RVF, describes individual risk more accurately than earlier models. Importantly, it also works well in a variety of situations. After creating the risk calculator, the researchers “checked their work” by using it to calculate risks retrospectively for patients in another hospital system. The scientists then compared the calculator’s predictions to the patients’ real-world outcomes, finding that their tool was still able to accurately model patients’ risk of subsequently developing right heart failure.