To recognize coronary artery disease. It turned out to be the fundamental method of differentiating the cause of dilated cardiomyopathy (DCM), which also included ischemic cardiomyopathy or the assignment of idiopathic. One of the emerging methods of pinpointing myocardial scar and recognizing etiology was the late gadolinium enhancement (LGE) with cardiovascular magnetic resonance (CMR). Patients with left ventricular dilation and dysfunction ascribed to idiopathic DCM were part of the DCM Precision Medicine Study. However, expert clinical review ruled out ischemic or other cardiomyopathies. A coronary artery disease with more than 50% narrowing at angiography of 1 or above epicardial coronary artery delineated ischemic cardiomyopathy. Researchers did not need CMR for this study. Yet, they classified patterns of LGE in three categories after a post hoc analysis of the available CMR reports. The categories were no LGE, ischemic-pattern LGE: subendocardial/transmural, and nonischemic LGE: mid myocardial/epicardial.

The researchers examined 1,204 DCM patients. They found a prior CMR study of 396 patients (32.9%). Of these 396 patients, 327 (82.6%) had LGE imaging (mean age 46 years; 53.2% male; 55.4% White). Out of these 327 patients, 178 (54.4%) exhibited LGE, 156 (47.7%) had LGE consistent with idiopathic DCM, and 22 (6.7%) had transmural or subendocardial LGE. In the cases of the 22 patients, 13 had normal coronary angiography, and 3 exhibited luminal irregularities. Also, one of them had a distant thrombus, and another had coronary artery disease with less than 50% coronary artery narrowing. But, coronary angiography was not available for four patients.

Only 327 patients in the study had LGE-CMR data available. Out of these 327 patients, the researchers found 22 (6.7%) patients with ischemic-pattern of LGE. An expert clinical review determined that all of them had idiopathic DCM.