BALTIMORE, May 11 (UPI) -- A 3D heart assessment, based on imaging of individual patients, was shown to be more accurate at predicting heart arrhythmia and sudden cardiac arrest than other standard measures, according to a new study.
Researchers at Johns Hopkins University found it was more precise than more invasive methods for diagnosing heart risk, suggesting some patients could avoid the implantation of defibrillators.
The researchers designed the virtual-heart arrhythmia risk predictor, or VARP, using MRI scans of patients' hearts, which are assembled into a 3D representation of the organ.
Using representations of the electrical processes in cardiac cells and communication between them, the researchers created models for individual patients in their recent proof-of-concept study. They incorporated the shape of a patient's heart, how electrical waves move through it and the impact of any scar tissue in making predictions about future cardiac events.
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"We demonstrated that VARP is better than any other arrhythmia prediction method that is out there," Natalia Trayanova, a professor of biomedical engineering at Johns Hopkins University, said in a press release. "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."
For the study, published in the journal Nature Communications, researchers used MRI scans for 41 patients who survived a heart attack but developed scar tissue that increases the risk for arrhythmia.
Each of the patients was scheduled to have a defibrillator implanted in their heart. Using MRI scans of the patients' hearts, the researchers ran VARP. All 41 had an ejection fraction, the measure of blood being pumped out of the heart, at levels low enough to necessitate a defibrillator.
Patients whose VARP results predicted arrhythmia also were four times more likely to develop one, results researchers said were four to five times better than measuring ejection fraction or other predictions of risk.
"Our virtual heart test significantly outperformed several existing clinical metrics in predicting future arrhythmic events," Trayanova said. "This non-invasive and personalized virtual heart-risk assessment could help prevent sudden cardiac deaths and allow patients who are not at risk to avoid unnecessary defibrillator implantations."
