Prevalence of cardiomyopathies and myocardial scar in patients with non-complicated premature ventricular beats: a CMR study

Abstract Introduction Frequent or symptomatic premature ventricular beats (PVBs) in subjects with no personal or family history of cardiac disease or sudden death is a recurrent motive for cardiac magnetic resonance (CMR) prescriptions. This represents a significant burden on healthcare services, given the low availability of CMR technique. If CMR is a recommended imaging modality in patients with history of cardiac arrest due to ventricular arrhythmia, sustained ventricular arrhythmias or when first-line tests are abnormal, its diagnostic value in this specific setting has not been evaluated. Purpose To determine the prevalence of significant CMR abnormalities (myocardial fibrosis, arrhythmogenic cardiomyopathies) in patients with no personal nor family history of cardiac disease and non-complicated PVBs. Methods Between September 2010 and July 2021, 416 healthy adults with no personal nor family cardiac disease history underwent CMR at our institution to explore non complicated PVBs, and were retrospectively included (Figure 1). Right and left ventricular (RV/LV) function and dimensions were systematically evaluated on CMR, as the presence of myocardial late gadolinium enhancement (LGE). Criteria for cardiomyopathies (hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), ARVD), the presence and location of myocardial fibrosis were looked after. Results A total of 605 patients were referred for CMR to explore frequent PVBs, representing 14% of all tests performed during this period. Among them, 12 patients (3%) presented significant myocardial abnormalities possibly related to PVBs: 2 patients had sequelae of myocardial infarction and 3 of myocarditis, 1 patient had criteria of HCM and 1 of ARVD, finally 5 presented non-specific myocardial fibrosis (septal mid-wall LGE). In addition, after a mean follow-up of 5 years, there was no death in patients with abnormal CMR, and only 2 patients underwent transcatheter ablation for focal non complicated but symptomatic PVBs. There was no hospitalization for heart failure. Conclusion In patients with non-complicated PVBs and no history of cardiac disease, the rate of cardiomyopathy pattern or myocardial scar on CMR is very low (3%). In this specific population, events were very rare: frequent isolated PVBs, even when associated with myocardial abnormalities, were a benign condition in our study. Given the high volume of patients referred for this indication in daily practice (14% of total CMRs in our center), the limited availability and high costs of CMR, and the difficulties of CMR sequences acquisition in the context of frequent PVBs (possibly leading to misdiagnosis), these data suggest that we should refine the selection of patients undergoing CMR for PVBs exploration.