Clinical Report


Authors: Baig MK, Goldman JH, Caforio AP, Coonar AS, Keeling PJ, and McKenna WJ.
Journal: J Am Coll Cardiol, 1998;31:195-201.
Department of Cardiological Sciences, St. George’s Hospital Medical School, London, England, United Kingdom.
PubMed Link: PMID: 9426040
Citation Type: phenotype (clinical data only).
Study Design: prospective evaluation of relatives of patients with idiopathic dilated cardiomyopathy.
Study Measurements: echo, ECG
Summary: Summary: 110 consecutive patients with documented IDC were offered screening and inclusion in the study. Family pedigrees for these 110 patients accounted for 430 relatives who were contacted (presumably primarily first degree relatives, although the degree of relatives was not specified in the report). Four hundred and eight subjects from 89 families (81% of all families, with an average of 4.6 members per family), agreed to be screened. The number of subjects excluded were as follows:  54 (13%) because of age < 16 years; 79 (19%) because of hypertension (blood pressure > 150/90 for > 1 year) or high alcohol intake; 50 (12%) with insufficient data usually due to geographic considerations. This left 225 relatives, average age of 35±15 years for analysis.  From this group, they observed that 29% of relatives of had abnormal echocardiograms. Left ventricular enlargement (LVE), the most common finding, was observed in 45, or 20% of subjects. In this study LVE was defined by an LVEDD of 112%. Thirteen (6%) had a decreased fractional shortening, an echocardiographic measure of systolic function, defined as less than 25% for this study.  Finally, 7 subjects (3%) had dilated cardiomyopathy with LVE and decreased systolic function.  Of particular interest, 12 of the 45 subjects (27%) with LVE, but none of the subjects with only decreased fractional shortening, developed symptomatic dilated cardiomyopathy over a median 39 month follow up period.  A variety of exercise and electrocardiographic (including signal averaged measures) variables were also evaluated, but stepwise logistic regression analysis only demonstrated LVEDD to be of predictive value for the progression from LVE to symptomatic dilated cardiomyopathy.  Finally, and perhaps most importantly, the authors noted that if left ventricular enlargement in family members was taken as early evidence of disease, then the prevalence of FDC among index patients with IDC rises to 48%.
Comment: This study indicated that using LVE as an indicator of FDC in relatives, up to 48% of families would have FDC.