Abstract 20578: Absence of Family History Predicts a Low Yield for Genetic Testing in a Community Cardiomyopathy Clinic
Objective: Although guidelines exist suggesting indications for genetic testing in inherited cardiomyopathy, the yield of testing outside specialized quarternary referral centers remains unexplored. We aimed to assess the yield of genetic testing in a community cardiomyopathy clinic. We further aimed to assess the impact of presence or absence of family history (broadly defined) on the yield of genetic testing.
Methods: Clinical characteristics and genetic results for all patients seen in the Yale Cardiomyopathy Clinic were prospectively entered into a clinical database (n=771) over 5 years. 209 (27.1%) underwent genetic testing to determine the presence of pathogenic mutations. 43 family screens were excluded from analysis yielding a total n of 166. Pathogenic mutations were defined by the destination lab at the time of reporting. For the purposes of this analysis family history was defined as presence of any of the following on 3 generation pedigree: cardiomyopathy, pacemaker, defibrillator, sudden cardiac death, LVAD and/or heart transplant.
Results: Of those undergoing genetic testing, 71 (42.8%) had hypertrophic cardiomyopathy (HCM), 51 (30.7%) had dilated cardiomyopathy (DCM), 9 (5.4%) had arrhythmogenic ventricular cardiomyopathy (ARVC/ALVC) and 35 (21.1%) had unclassified cardiomyopathy. Pathogenic mutations were found in 38% of HCM cases (27/71), 35.3% of DCM cases (18/51), 33.3% of ARVC/ALVC cases (3/9) and 20% of unclassified (7/35). A negative family history predicted a poor yield (9/57, 15.8%) of pathogenic mutations versus a positive family history (46/109, 42.2%) with a p value of 0.0005.
Conclusion: Absence of family history predicts a low yield for genetic testing in a community cardiomyopathy clinic. As genetic testing moves into community practice, presence or absence of broadly defined family history may guide physicians in counseling their patients about the yield of potentially costly, complex testing.
Author Disclosures: N. Mehta: None. M. Marieb: None. L. Bellumkonda: None. D. Jacoby: None.
- © 2014 by American Heart Association, Inc.