Objectives: We evaluated the feasibility of using late gadolinium- enhanced(LGE) cardiovascular magnetic resonance(CMR) to distinguish left ventricular(LV) systolic dysfunction related or not to coronary artery disease(CAD) in patients with heart failure(HF) but without clinical suspicion of CAD as the underlying cause. Background: In patients with known CAD, LGE- CMR is capable of distinguishing LV systolic dysfunction related to CAD from dilated cardiomyopathy. Methods: Seventy- one patients with HF and LV systolic dysfunction,without a previous history of myocardial infarction, with neither Q waves nor clinical data suggesting CAD, underwent both LGE- CMR and coronary angiography. Results: Twenty- six patients(37% ) had angiographically proven CAD(< 70% stenosis of a major epicardial vessel)(angio[+ ] group), and 45(63% ) had unobstructed coronary arteries(angio[- ] group). Twenty- one patients in the angio(+ ) group(21 of 26, 81% ) showed subendocardial and/or transmural enhancement, whereas only 4(9% ) of 45 in the angio(- ) group showed it(p< 0.001). In 7 patients(7 of 71, 10% ),we found a different pattern of mid- wall enhancement- namely, 3 of 26 patients in the angio(+ ) group and 4 of 45 in the angio(- ) group(11% vs. 9% , p=0.7). Mid- wall enhancement in the angio(+ ) group was distributed in segments other than those which had subendocardial enhancement. Conclusions: In patients with HF and LV systolic dysfunction without clinical suspicion of CAD, LGE- CMR is an excellent tool for classifying patients in relation to the presence or absence of underlying CAD. Thus, CMR might offer a valid alternative to coronary angiography for the detection of CAD in these patients. Objectives: We evaluated the feasibility of using late gadolinium-enhanced (LGE) cardiac magnetic resonance (CMR) to distinguish left ventricular (LV) systolic dysfunction related or not to coronary artery disease (CAD) in patients with heart failure (HF) but without Background: In patients with known CAD, LGE-CMR is capable of distinguishing LV systolic dysfunction related to CAD from dilated cardiomyopathy. Methods: Seventy-one patients with HF and LV systolic dysfunction, without previous history of myocardial infarction, with neither Q waves nor clinical data suggested CAD, underwent both LGE-CMR and coronary angiography. Results: Twenty- six patients (37%) had angiographically proven CAD (<70% stenosis of a major epicardial vessel) Twenty-one patients in the angio (+) group (21 of 26, 81%) showed subendocardial and / or transmural (angio [+] group), and 45 enhancemen In 7 patients (7 of 71, 10%), we found a different pattern of mid-wall enhancement (45%) of 45 in the angio (-) group showed it (p <0.001). , 3 of 26 patients in the angio (+) group and 4 of 45 in the angio (-) group (11% vs. 9%, p = 0.7). Mid-wall enhancement in the angio (+) group was distributed in segments other than those which had subendocardial enhancement. Conclusions: In patients with HF and LV systolic dysfunction without clinical suspicion of CAD, LGE-CMR is an excellent tool for classifying patients in relation to the presence or absence of underlying CAD. Thus, CMR might offer a valid alternative to coronary angiography for the detection of CAD in these patients.