It is well established that midwall myocardial fibrosis is a strong prognostic indicator in DCM,4,18 and it would be reasonable to expect that the proportion of patients with midwall myocardial fibrosis would be highest in subtype 3, the group with marked biventricular impairment, higher plasma concentrations of biomarkers associated with an adverse prognosis (troponin, NT-proBNP), and greater symptom burden. This evidence concerns the gene NPPB and familial dilated cardiomyopathy.