Identification and prognostication of the substrate of ventricular arrhythmia with cardiac magnetic resonance (CMR) imaging in patients with normal echocardiography

Type of funding sources: Other. Main funding source(s): Self Malignant ventricular arrhythmia contributes to approximately half of the sudden cardiac deaths. In common practice, echocardiography is used to identify structural heart diseases that are the most frequent substrate of VA. Identification and prognostication of structural heart diseases are very important as they are the main determinant of poor prognosis of ventricular arrhythmia. Purpose : The objective of this study is to determine whether cardiac magnetic resonance (CMR) may identify structural heart disease (SHD) in patients with ventricular arrhythmia who had no pathology observed on echocardiography. Methods : A total of 864 consecutive patients were enrolled in this single-center prospective study with significant ventricular arrhythmia. VA was characterized as >1000 ventricular ectopic beats per 24 hours, non-sustained ventricular arrhythmia, sustained ventricular arrhythmia, and no pathological lesion on echocardiography. The primary endpoint was the detection of SHD with CMR. Secondary endpoints were a composite of CMR detection of SHD and abnormal findings not specific for a definite SHD diagnosis. Results : CMR studies were used to diagnose SHD in 212 patients (24.5%) and abnormal findings not specific for a definite SHD diagnosis in 153 patients (17.7%). Myocarditis (n = 84) was the more frequent disease, followed by arrhythmogenic cardiomyopathy (n = 51), ischemic heart disease (n = 32), dilated cardiomyopathy (n = 17), hypertrophic cardiomyopathy (n = 12), congenital cardiac disease (n = 08), left ventricle noncompaction (n = 5), and pericarditis (n = 3). The strongest univariate and multivariate predictors of SHD on CMR images were chest pain (odds ratios [OR]: 2.5 and 2.33, respectively) and sustained ventricular tachycardia (ORs: 2.62 and 2.21, respectively). Conclusion : Our study concludes that SHD was able to be identified on CMR imaging in a significant number of patients with malignant VA and completely normal echocardiography. Chest pain and sustained ventricular tachycardia were the two strongest predictors of positive CMR imaging results. Abstract Figure. Distribution of different SHD