Optimized whole-heart MRCA may accurately rule out CAD
MedWire News: Japanese researchers suggest that non-contrast enhanced whole-heart magnetic resonance coronary angiography (MRCA) may be a useful tool for excluding significant coronary artery disease (CAD) in chest pain patients suspected to have the condition.
In fact, MRCA at 1.5-T ruled out significant CAD, defined as luminal narrowing of ≥50%, with an accuracy of 88% among these patients, say Hajime Sakuma (Mie University Hospital, Tsu) and colleagues.
This, they explain, indicates MRCA's ability to perform a role similar to the gold standard X-ray coronary angiography (CAG), in a shorter imaging time, with less expense, and no exposure to radiation and contrast.
They warn however: "The current whole-heart 1.5-T MRCA approach is optimized for assessing luminal stenoses in the coronary arteries and does not provide sufficient information regarding the presence and characteristics of atherosclerotic plaque in the coronary arterial wall."
The team recruited 127 suspected CAD patients with chest pain and a mean age of 67 years. All patients underwent whole-heart MRCA in a mean time of 9.5 minutes, followed by X-ray CAG.
Sakuma and colleagues then assessed the resulting images for significant coronary artery luminal narrowing (≥50%), and compared the accuracy of the MRCA findings to those of X-ray CAG.
As reported in the Journal of the American College of Cardiology the team found that the optimized whole-heart MRCA technique had a sensitivity of 88%, a specificity of 72%, a positive predictive value of 71%, and a negative predictive value (NPV) of 88%.
Of note, left main coronary artery stenosis and triple-vessel disease were excluded by MRCA with an NPV of 99%.
In an accompanying editorial, Eike Nagel (King's College London, UK) commented: "Compared with computed tomographic angiography, MRCA is still a cumbersome method with a higher failure rate, longer scan times, and less accuracy due to lower PPV.
However, he acknowledged that the current study shows that "MRCA is evolving slowly but steadily, and we should continue to look out for this method."
He added: "Scar tissue, which is a strong prognostic parameter in ischemic heart disease, can be detected [by MRCA] with excellent accuracy."
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By Lauretta Ihonor