Won et al, reported the potential utility of findings on late gadolinium enhancement (LGE) and cine images acquired with cardiac magnetic resonance imaging to differentiate ischemic from nonischemic cardiomyopathy in patients with newly diagnosed heart failure with reduced left ventricular ejection fraction. There are few comments on the method and finding of this study. First, 70% of study population had elevated troponin, which indicated high-risk group of patients with heart failure who might require more aggressive or invasive strategy than those without elevated troponin. Second, cardiac magnetic resonance images were acquired from either 1.5 T or 3.0 T magnetic resonance imaging (MRI) system. There were no validation data provided to demonstrate that the image parameters from 2 different MRI systems were comparable and did not affect the interpretation of wall motion, and the extent of defect seen in first pass perfusion and LGE images. The contrast-enhanced image qualities have been reported to be superior in 3.0 T MRI system with better signal and contrast to noise ratios compared with 1.5 T MRI system. Third, 8% of ischemic cardiomyopathy group did not demonstrate LGE and the diagnostic accuracy of combined ischemic pattern from LGE and regional wall motion abnormality from cine images to detect ischemic cardiomyopathy was 71%. This may not provide enough confidence for clinicians to decide whether patients should undergo or omit invasive coronary angiography to exclude significant coronary artery disease. Additional information on the presence and extent of ischemic myocardium may be useful to guide management in these patients because the presence of inducible myocardial ischemia from stress cardiac magnetic resonance imaging was an important predictor for cardiac events.

Coronary computed tomographic angiography has emerged as an alternative cardiac imaging method to detect etiology in newly diagnosed heart failure or dilated cardiomyopathy. It provides excellent sensitivity and negative predictive value for the presence of significant coronary artery disease. With the advancement of hardware and software, the role of noninvasive cardiac imaging has been increasing as a gatekeeper to invasive coronary angiography in patients newly diagnosed heart failure with reduced left ventricular ejection fraction, and further study is needed to define the best cost-effective cardiac imaging strategy for these patients.