Epidemiology of non-ischaemic dilated cardiomyopathy.

Dilated cardiomyopathy, defined by left ventricular dilatation and systolic dysfunction, is a major cause of heart failure, heart transplantation and sudden cardiac death, especially in young and middle-aged adults. Dilated cardiomyopathy of non-ischaemic aetiology is more common than once thought, with current prevalence estimated at around 1 in 220 based on cardiac magnetic resonance imaging studies, and the prevalence is twice as high in men than in women. However, the true prevalence could be even higher when early or subclinical forms of the disease are considered. Advances in genetic technologies over the past three decades have led to improved understanding of the genetic basis of non-ischaemic dilated cardiomyopathy and the identification of pathogenic variants in 30-40% of patients. The genetic architecture of this disease is complex and heterogeneous. Rather than being a strictly monogenic disorder, dilated cardiomyopathy results from a combination of monogenic and polygenic factors, along with gene-environment interactions as critical modifiers of disease penetrance and phenotype. A deeper understanding of the genetic factors and epidemiological landscape of dilated cardiomyopathy is crucial for improving clinical management and optimizing screening protocols and public health strategies.