Rescreening of "healthy" relatives of patients with dilated cardiomyopathy identifies subgroups at risk of developing the disease

To test the diagnostic impact of the non-invasive rescreening of relatives of index patients consecutively diagnosed as having dilated cardiomyopathy. The aim of rescreening asymptomatic healthy relatives of DCM patients is to diagnose newly affected subjects and evaluate the predictive significance of the instrumental abnormalities found at the first screening. Two hundred and three healthy relatives of 73 consecutive index patients with DCM (18 with familial disease at first screening) underwent rescreening involving a clinical examination, electro- and echocardiography, and biochemical tests a median of 29.3 months after the first screening. Seven relatives had developed the diagnostic criteria for DCM during the screening-rescreening interval. Of the 24 healthy relatives with left ventricular end-diastolic diameter enlargement and normal function at the first screening, nine had normalised, seven showed persistent enlargement, three had worsened, and five had developed the disease criteria at rescreening. Of the three relatives with atrioventricular block at the first screening, one had developed DCM. Finally, one of the relatives with normal echocardiographic and electrocardiographic results at the first screening, had developed the disease. Three of the newly diagnosed subjects came from families with evidence-based familial DCM, and four from families with what was defined as sporadic DCM at the first screening. Medium-term rescreening of the relatives of DCM patients can identify a significant number of newly affected patients (3.5%).