Abstract 11703: Cardiovascular Magnetic Resonance, Fibrosis and Prognosis in Ventricular Arrhythmias
Introduction: Risk stratification for device therapy is challenging. Current guidelines target patients with a previous cardiac arrest or those with reduced EF. The presence of fibrosis detected with CMR has been shown to be predictive of serious cardiac events in several defined sub-sets of patients. We tested the hypothesis that fibrosis is an independent predictor of hard clinical events in all patients presenting with any type of ventricular arrhythmia.
Methods: 495 consecutive patients (mean age 50±15 years) with a documented episode of NSVT (n=245), sustained VT (n=201) or VF (n=49) underwent CMR with quantitative assessment of function [left ventricular volumes, (LVV) and mass, (LVM)] and fibrosis. The group was prospectively followed-up for a median of 2.3 years (range 0-10.5 years). The primary outcome was a composite of cardiac death/arrest, new episode of sustained VT or appropriate ICD discharge. Multivariate analyses were constructed from the univariate significant predictors and tested in the VT+VF group and the NSVT group.
Results: Mean EF of the study patients was 60±12%. In patients presenting with VT and NSVT those with fibrosis are predominantly male, are more likely to have a history of CAD and have increased LVV and LVM and reduced EF (p<0.01). In patients presenting with VF the only other significant abnormality found in those with fibrosis was an increased LVM (p<0.05). In the VT+VF group, patients with LV fibrosis were more likely to reach a primary outcome compared to those without fibrosis (HR=4, 95% CI: 1.5-11, p<0.01). Also in the VT+VF group, as expected, an EF<30% was predictive of events (HR=2.3, 95% CI=1.3-7), whereas the assessment of EF with a 55% cut-off limit was not a significant predictor. In the NSVT group, those with fibrosis were more likely to reach a primary outcome (HR=3.7, 95% CI: 1.5-9.4, p<0.01) compared to those without fibrosis and this was the only significant predictor of events.
Conclusion: CMR-detected fibrosis is an important predictor of outcome in all patients presenting with ventricular arrhythmia and this could have additional implications to current recommendations in guiding ICD therapy for primary and secondary prevention.
- © 2011 by American Heart Association, Inc.