Comparison of Cardiac Magnetic Resonance Imaging Findings and Prognostic Measures in Nondilated Cardiomyopathy and Dilated Cardiomyopathy

<b>Introduction:</b> Nondilated left ventricular cardiomyopathy (NDLVC) is a newly defined category of cardiomyopathy. We sought to evaluate and compare the phenotype of NDLVC with DCM using cardiac magnetic resonance (CMR) imaging and to investigate the prognostic significance of these conditions. <b>Methods:</b> One hundred and fifty patients suspected of having cardiomyopathy referred for CMR were recruited. We considered 3 groups; Group 1: NDLVC-reduced EF, (NDLVC-REF), LVEF ≤ 40%, Group 2: NDLVC-mildly reduced EF(NDLVC-MREF), 40 < LVEF < 50, Group 3: Dilated cardiomyopathy (DCM). All selected patients were followed up for a median of 24 months to determine the composite cardiac endpoint consisting of mortality and/or hospitalization for cardiovascular reasons (composite cardiac event (CCE)) as the primary endpoint. <b>Results:</b> The mean age (SD) was 42.6 (13.7) years (range: 18-77 years). There was no association between the presence of myocardial LGE and the development of atrial and/or ventricular arrhythmias. Atrial fibrillation was most common in the NDLVC groups during the follow-up period. Myocardial late gadolinium enhancement (LGE) was also more pronounced in the DCM group. Most patients in the NDLVC groups had no LGE. LGE in the midwall was the most common LGE pattern in all three groups and the septal wall was the most commonly affected area of the LV. There was no significant difference between the CMR findings of patients with and without CCE in each subgroup. However, the presence of myocardial replacement fibrosis was higher in patients with a CCE in total study population, (<i>n</i> = 144, 68% versus 32%, <i>p</i>=0.03), but the difference was not significant in subgroup analyzes. <b>Conclusion:</b> NDLVC has a relatively good prognosis in recent times. The consideration of NDLVC in a spectrum with DCM can be reasonable. However, the prognostic risk factors need to be investigated in more detail.