Abstract 3742: Strain Echocardiography Suggests Plakophilin-2 Mutation is Associated With a Milder Functional Phenotype in Arrhythmogenic Right Ventricular Dysplasia
Background: Arrhythmogenic Right Ventricular Dysplasia (ARVD) is an inherited cardiomyop-athy characterized by fibro-fatty myocardial replacement in the right ventricle (RV) and presents with heart failure and arrhythmias. A mutation in a desmosomal cell junction protein, plakophilin-2 (PKP2), has been recently reported in ARVD patients. We examined the relationship between PKP2 mutation and right ventricular function in ARVD patients using strain echocardiography (SE).
Methods: We genotyped 30 patients with ARVD confirmed by Task Force criteria. All ARVD patients and 30 age-matched healthy volunteers underwent SE. Peak systolic strain and strain rate were measured at the mid-RV free wall.
Results: PKP2 mutation was found in 13 of 30 ARVD patients (43%). Mean age in PKP2 (+) was lower than PKP2 (−) patients (32±10 vs. 40±14 years, p<0.01). RV outflow tract diameter and fractional area change were similar in PKP2 (+) and (−) patients. RV strain rate ((−1.0±0.7 s−1 vs. −2.0±1 s−1, p<0.002) and strain (−10±16% vs.–28±22%, p<0.001) were lower in all ARVD compared to controls, respectively. RV strain below 2 standard deviations of the mean value for controls was considered abnormal right ventricular function. Using this definition, abnormal right ventricular function was detected in a larger number of PKP2 (−) vs. PKP2 (+) patients (44% vs. 8%, p= 0.03).
Conclusion: PKP2 mutation is relatively common in the United States ARVD population and its presence appears to be associated with a milder phenotype.