Cardiovascular magnetic resonance (CMR) criteria along with family history can determine those patients in whom a (likely) pathogenic variant ((L)PV) for noncompaction cardiomyopathy can be identified, subsequently leading to referral for genetic diagnostics and cascade screening, according to a study published in the Canadian Journal of Cardiology.
Diagnosing a (L)PV in a cardiomyopathy gene is critical as it allows for the accurate identification of relatives at risk as well as predicting prognosis. In this study, researchers sought to evaluate the clinical and morphologic characteristics of the myocardium that may predict a (L)PV and the best CMR diagnostic criteria for that task.
CMR and genetic data of 62 patients with noncompaction cardiomyopathy from 45 families (n=33 with and n=29 without (L)PV, diagnosed by echocardiographic Jenni criteria, were analyzed retrospectively. DNA testing was conducted and CMR imaging was performed on clinical 1.5 T (n=46) and 3 T (n=16) magnetic resonance imaging systems. All CMR images were assessed blinded to the outcomes of DNA testing.
In 53% of the patients, a (L)PV in a cardiomyopathy gene was identified. The dominant locations for meeting Stacey and/or Peterson criteria were the apical and mid-lateral segments. Correlations between diverse CMR criteria varied from moderate to very strong. Multivariate binary logistic regression analysis with CMR and non-CMR parameters indicated that familial cardiomyopathy, trabecular mass, and meeting Petersen criteria in ≥2 long axis views were independent predictors for finding a (L)PV. Specifically, familial cardiomyopathy was documented in 56% of patients, and patients with familial cardiomyopathy were more likely to have a (L)PV (P =.03). In contrast, left bundle branch block and hypertension were independent negative predictors of a (L)PV.
Study limitations include selection bias and underreporting of genetic causes.
”These findings may help guiding referral for genetic diagnostics and cascade screening,” noted the study authors.
van Waning JI, Caliskan K, Chelu RG, van der Velde N, Pezzato A, Michels M, et al. Diagnostic CMR imaging criteria in noncompaction cardiomyopathy and the yield of genetic testing (published online May 21, 2020). Can J Cardiol. doi.org/10.1016/j.cjca.2020.05.021