LAUSR

Non-ischaemic dilated cardiomyopathy (DCM), despite its apparently simple definition, incorporates several aetiologies. Currently, the advent of next-generation sequencing techniques has demonstrated that genetic mutations are responsible for approximately 50% of DCM. In the remaining cases, a complex interaction between environmental triggers (e.g. inflammation, tachyarrhythmias, alcohol, chemotherapy) and specific genetic backgrounds lead to the dilated phenotype.1 Although the prognosis of DCM has improved significantly over the past decades with advances in pharmacological and non-pharmacological treatments,2 DCM still remains the leading cause of heart transplantation. Therefore, clinical presentation and subsequent outcomes are barely generalizable; furthermore, management of DCM is difficult and needs to be implemented. Affected patients are generally relatively young, with a low co-morbidity profile and thus low event rates during the follow-up. This scenario dramatically limits the statistical power of focused studies, which require enrolment of a large number of patients before definitive conclusions can be made. In this issue of the Journal, Halliday et al.3 pointed out all the above-mentioned critical issues. Furthermore, and most importantly, they eloquently evaluated the prognostic role of gender differences in the natural history of DCM patients. Over 10 years of follow-up, they enrolled almost 900 well-characterized DCM patients. The main result of their study is the better long-term outcome of women compared to men, even after adjustment for the major prognostic determinants of the disease. Besides gender, older age emerged, as expected, as an important prognostic predictor, since after 60 years of age the competitive risk of non-cardiac death progressively increases, as stated by the same authors.3 Up until now, the role of gender differences in DCM has been only loosely considered as a significant outcome modifier. Data from this registry3 confirm previous findings from a similar Italian registry regarding the different clinical presentation and the