Echocardiographic Evaluation in Asymptomatic Relatives of Patients with Dilated Cardiomyopathy Reveals Preclinical Disease

19 July 2005 | Volume 143 Issue 2 | Pages 108-115

Background: Idiopathic dilated cardiomyopathy is often familial, and apparently healthy relatives may have latent, early, or undiagnosed established disease.

Objective: To determine the prevalence and natural history of asymptomatic cardiac abnormalities among sampled relatives of unselected patients referred for management of dilated cardio-myopathy.

Design: Prospective cohort study.

Patients: 767 asymptomatic relatives of 189 consecutive unselected patients with dilated cardiomyopathy.

Measurements: Clinical evaluation, including history, physical examination, electrocardiography, and echocardiography, was performed. Participants were classified in accordance with published echocardiographic criteria. Sampled relatives who did not have evidence of dilated cardiomyopathy at the initial evaluation were followed for a median of 57 months (range, 1 to 133 months).

Results: Of the 767 patients evaluated, 592 (77.2%) were assessed as healthy, 35 (4.6% [95% CI, 3.7% to 7.6%]) had dilated cardiomyopathy, 119 (15.5% [CI, 12.5% to 18.8%]) had left ventricular enlargement without systolic dysfunction, and 21 (2.7% [CI, 1.9% to 4.9%]) had depressed fractional shortening without ventricular dilatation. At follow-up, progression to dilated cardiomyopathy occurred in 13 (10%) relatives with left ventricular enlargement or depressed fractional shortening versus 3 (1.3%) healthy relatives. In a multivariate model, only left ventricular enlargement or depressed fractional shortening independently predicted progression to dilated cardiomyopathy (hazard ratio, 10.0 [CI, 2.8 to 35.5]; P < 0.001).

Limitations: Because relatives had to be willing to participate and be available geographically, selection bias may have occurred.

Conclusion: Treatable asymptomatic dilated cardiomyopathy was identified in 4.6% of asymptomatic relatives. In addition, left ventricular enlargement and depressed fractional shortening were common in asymptomatic relatives of patients with dilated cardiomyopathy and were associated with a statistically significant medium-term risk for disease progression. Evaluation of relatives of patients with cardiomyopathy is recommended.

Editors' Notes Context Idiopathic dilated cardiomyopathy is familial in 25% of cases. However, identifying asymptomatic affected relatives is difficult because there is no specific molecular marker for the disease and penetrance of the genetic defect is incomplete. The natural history of asymptomatic disease is poorly defined. Contribution Clinical evaluation of asymptomatic relatives of patients with dilated cardiomyopathy showed that those with left ventricular enlargement or depressed fractional shortening were nearly 8 times as likely to progress to dilated cardiomyopathy as those with normal findings. Implications Screening of asymptomatic relatives of patients with dilated cardiomyopathy seems useful since early treatment may improve prognosis in affected individuals. –The Editors

 

Author and Article Information

From St. George's Hospital Medical School, London, United Kingdom; Massachusetts General Hospital, Charlestown, Massachusetts; and University of Padua, Padua, Italy.

Acknowledgments: The authors gratefully acknowledge the contributions of Phil Keeling, Jonathan Goldman, Kamran Baig, Carol Page, and Mary Gould to this work.

Grant Support: Drs. Mahon, Murphy, and McKenna were supported by the British Heart Foundation, and Dr. Caforio was supported by the Veneto Region Target Project and the Ministero dell'Università e della Ricerca Scientifica e Tecnologica (MURST) Target project.

Potential Financial Conflicts of Interest: Grants pending: C.A. MacRae (National Institutes of Health).

Requests for Single Reprints: William J. McKenna, MD, The Heart Hospital, Westmoreland Street, London W1G 8PH, United Kingdom; e-mail, william.mckenna{at}uclh.org.

Current Author Addresses: Dr. Mahon: Department of Cardiology, Mater Misericordiae Hospital, Eccles Street, Dublin 7, Ireland.

Drs. Murphy, Elliott, and McKenna: The Heart Hospital, Westmoreland Street, London W1G 8PH, United Kingdom.

Dr. McRae: Cardiovascular Research Center, 149 13th Street, 4th Floor, Charlestown, MA 02129.

Dr. Caforio: Division of Cardiology, Department of Clinical and Experimental Medicine, University of Padua, Policlinico Universitario, Centro V. Gallucci, via N. Giustiniani, 2, 35128 Padova, Italy.

Author Contributions: Conception and design: N.G. Mahon, C.A. MacRae, A.L.P. Caforio, P.M. Elliott, W.J. McKenna.

Analysis and interpretation of the data: N.G. Mahon, P.M. Elliott, W.J. McKenna.

Drafting of the article: N.G. Mahon, R.T. Murphy, W.J. McKenna.

Critical revision of the article for important intellectual content: R.T. Murphy, C.A. MacRae, A.L.P. Caforio.

Final approval of the article: C.A. MacRae, P.M. Elliott, A.L.P. Caforio, W.J. McKenna.

Provision of study materials or patients: N.G. Mahon.

Statistical expertise: N.G. Mahon.

Obtaining of funding: N.G. Mahon, W.J. McKenna.

Administrative, technical, or logistic support: P.M. Elliott, W.J. McKenna.

Collection and assembly of data: N.G. Mahon, R.T. Murphy.