Stress cardiac MRI (CMR) isn’t common in clinical practices, but Duke Health researchers found the modality may hold promise as an alternative to more commonly used cardiovascular techniques for predicting fatal heart disease, according to a Feb. 8 study published in JAMA: Cardiology.
“We've known for some time that CMR is effective at diagnosing coronary artery disease, but it's still not commonly used and represents less than one percent of stress tests used in this country," said senior author Robert Judd, PhD, co-director of the Duke Cardiovascular Magnetic Resonance Center, in a university release.
Judd and colleagues looked at data from more than 9,000 patients (median age of 63 and median body mass index of 29) who underwent CMR across seven U.S. hospitals, amounting to 10 years of follow-up.
They found, after multivariable analysis, adding stress CMR improved mortality prediction in two different risk models and resulted in an 11.4 percent improvement in risk reclassification.
In patients with no history of heart disease and low risk based on well-established clinical criteria, those with an abnormal CMR scan were 3.4 times more likely to die than patients with a normal scan. The strong association between an abnormal stress CMR and mortality remained after adjusting for patient age, sex and cardiac risk factors.
Widespread adoption of stress CMR has been limited by a number of factors, including a few good quality labs and a lack of data on patient outcomes. However, prior studies have demonstrated stress CMR as one of the more accurate methods to identify functionally significant CAD, according to the authors.
And according to CMS statistics, the number of stress CMRs lags far behind comparable techniques. In 2016, the center reported more than 370,000 stress echocardiograms and more than 2 million stress nuclear exams were performed, compared to the 2,447 stress CMR exams.
At the very least, Judd et al. argues their study establishes a need to test stress CMR against these more widely-used methods.
"With the findings from this study suggesting that stress CMR is effective in predicting mortality, we provide a strong basis for a head-to-head study between stress CMR and other modalities," the group concluded.