Clinical Report


Authors: Mestroni L, Rocco C, Gregori D, Sinagra G, DiLenarda A, Miocic S, Vatta M, Pinamonti B, Muntoni F, Caforio L, McKenna W, Falaschi A, Giacca M, and Camerini F.
Journal: J Am Coll Cardiol, 1999;34:181-190.
International Centre for Genetic Engineering and Biotechnology, AREA Science Park, Trieste, Italy.
PubMed Link: 10400009
Citation Type: phenotype (clinical data only).
Study Design: evaluation of families of patients with idiopathic dilated cardiomyopathy.
Study Measurements: echocardiography, ECG; endomyocardial biopsy for histological examination of myocardium in some subjects; some skeletal muscle biopsies; some HLA typing.
Summary: Mestroni and co-workers reported the results of 350 patients with idiopathic dilated cardiomyopathy of 511 consecutive patients with primary cardiomyopathies evaluated from 1991-1997 at the International Centre for Genetic Engineering and Biotechnology in Trieste, Italy (18).  Dilated cardiomyopathy was based on strict criteria requiring an ejection fraction <45% or a fractional shortening <25% associated with LVE >117%. Detailed pedigrees were constructed for all index patients, and clinical screening of all families was offered regardless of family history. 60 families of the 350 patients were extensively investigated based on their geographic availability for screening.  There were 281 family members from the 60 families (average of 4.7 subjects per family) who completed screening; 39 of the 60 families (65%) had familial disease.  Notably, only 60 of 350 families (17.1%) underwent screening. When familial disease was compared to non-familial disease, only a younger age of onset was predictive of familial disease (sporadic IDC, 21 cases, average age 52 years, range 46-55, versus 39 cases of FDC, average age 37, range 26-45. Several subtypes of FDC were identified: 1) FDC as autosomal dominant (56%); 2) FDC as autosomal recessive (16%), with a worse prognosis; 3) FDC as X-linked (10%) associated with mutations of the dystrophin gene; 4) FDC as autosomal dominant with subclinical skeletal muscle disease (7.7%); 5) FDC with conduction system defects (2.6%); and 6) unclassifiable forms (7.7%).  Interestingly, histologic signs of myocarditis at endomyocardial biopsy (performed in 83 affected individuals during evaluation) were frequent but nonspecific.  Dr. Mestroni and co-workers concluded that while FDC is frequent, no particular clinical or morphological features of individual patients may distinguish FDC from IDC, and thus family screening is required to detect it.
Comment: This extensive study did not reveal any obvious clinical or histologic features that differentiated between sporadic and familial dilated cardiomyopathy