Epicardial to transmural. Moreover, in a recent publication from our group
Epicardial to transmural. Moreover, in a recent publication from our group, we have already shown the diagnostic value of novel myocardial tissue characterization techniques such as the measurement of extracellular volume fraction (ECV) based on T1-mapping pre- and post-contrast agent administration in BMD patients [29]. We could demonstrate that subtle diffuse myocardial fibrosis is present in LGE-negative myocardial areas. Hence, ECV measurement may also have a future role in risk stratifying of MD patients. The present study findings underline the importance of looking beyond the simple presence of LGE. In addition to that, the pattern of occurrence and further progression of LGE have to be considered, since the pattern and development of LGE reflect different pathomechanisms in different disease forms, e.g. in geneticallydriven versus acquired cardiac diseases: increased cell fragility and subsequent cell death with fibro-fatty myocardial replacement fibrosis in DMD/BMD vs. an inflammatory mediated process in myocarditis [30].Additive prognostic value of functional and structural CMRIn the present study, a LV-EF cut-off value of 45 resulted in the highest hazard ratio for identifying /discriminating patients with adverse cardiac events. Importantly, when we looked at those PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/28893839 patients with a LV-EF >45 (who were classified as low-risk buy ONO-4059 according to functional assessment only), the additive depiction of a transmural pattern of LGE (in at least one myocardial segment) allowed to identify those patients in this subgroup with significantly increased risk for adverse cardiac events – despite a LV-EF >45 . We hypothesize that (slow and rather diffuse) LGE progression to new myocardial regions directly relates to the continuous decline in LV systolic function, while the regional occurrence of transmural LGE – despite preserved LV systolic function – bears an independent negative prognostic value already in the early stages of cardiomyopathy from a functional point of view.Florian et al. Journal of Cardiovascular Magnetic Resonance 2014, 16:81 http://jcmr-online.com/content/16/1/Page 11 ofObviously, the identification of DMD/BMD patients who are at increased risk for adverse cardiac events despite a preserved LV systolic function (LV-EF >45 ) based on the detection of transmural LGE during CMR is not possible when cardiac work-up in these patients is limited to conventional echocardiography.Relationship between genotype and cardiac phenotypeIn the present study, DMD/BMD patients having dystrophin gene deletions in exons 50 and/or 51 showed less LGE, while patients with dystrophin gene duplications demonstrated more LGE regarding both LGE prevalence and extent. However, no association between the underlying genotype and the severity of cardiomyopathy, i.e. the degree of LV systolic impairment or LV dilatation, was found. Several previous studies attempted to relate the underlying dystrophin gene defect to the cardiac phenotype [5,31]. For example, Kaspar et al. related the locus of dystrophin gene mutation to the timing of cardiomyopathy onset, with an early onset for deletions affecting the amino-terminal domain (exons 2 to 9) and a later onset for deletions removing part of the central rod domain and hinge 3 (exons 50 and/or 51) [6]. In principle, our findings are not conflicting with the above data from Kaspar et al. However, one has to consider that there were differences in the study group (Kaspar et al. included patients with BMD and X-li.