Not everyone who has an irregular heartbeat is at risk for sudden cardiac death. And not everyone who has a heart attack is likely to develop arrhythmia. Acting on the side of caution however, cardiologists often implant small defibrillators in heart attack patients who they deem to be at risk based on a blood pumping measurement called “ejection fraction.” The downside of that decision is that the implants are invasive, costly, and add additional risks themselves.
Recently scientists and researchers at Johns Hopkins University developed an assessment technology that is much better at predicting arrhythmia risk than the blood pumping test. The team performed pre-implant MRIs from patients who were determined to need defibrillator implants. They used the MRIs to create personalized, virtual 3-D hearts. They then used the 3-D models to simulate the electrical processes in the heart to predict the likelihood that the virtual heart would develop arrhythmia. If the virtual heart-based predictions were accurate they could use the non-invasive MRI to rule out the invasive implant. The technology is called VARP, for virtual heart arrhythmia risk predictor.
The results were decisive. “Patients who tested positive for arrhythmia risk by VARP were four times more likely to develop arrhythmia than those who tested negative. Furthermore, VARP predicted arrhythmia occurrence in patients four-to-five times better than the ejection fraction and other existing clinical risk predictors, both non-invasive and invasive,” said Dr. Natalia Trayanova, the team leader. “We demonstrated that VARP is better than any other arrhythmia prediction method that is out there,” Trayanova said. “By accurately predicting which patients are at risk of sudden cardiac death, the VARP approach will provide the doctors with a tool to identify those patients who truly need the costly implantable device, and those for whom the device would not provide any life-saving benefits.”
Greater predictive accuracy, less costly, and less invasive make this Health Tech advance a triple win.
