Abstract 17489: Long Term Echocardiographic Follow-Up as Predictor of Ventricular Arrhythmias in Super-Responders to Cardiac Resynchronization Therapy
Background: Super-response to cardiac resynchronization therapy (CRT) is associated with extensive left ventricular (LV) reverse remodelling, resulting in significantly improved clinical outcome, echocardiographic function and survival. However, super-responders remain prone for ventricular arrhythmias. The aim of this study was twofold; 1) to evaluate whether LV reverse remodelling remains preserved during long term follow-up in super-responders and, 2) analyse the association between the course of LV reverse remodelling and ventricular arrhythmias.
Methods: All primary prevention CRT-D super-responders, defined as LV end systolic volume (LVESV) reduction of > 30% six months after implantation, were included. Device interrogations were scheduled every six months and echocardiographic evaluations were performed when clinically indicated. Cox regression analysis was performed with LVESV as time dependent variable to analyse the risk of ICD shock and its association with the course of LV reverse remodelling, the model adjusted for NYHA functional class, renal function, diabetes mellitus, usage of beta-blocker, digoxin or amiodaron.
Results: A total of 175 super-responders to CRT-D were included (mean age 67±9 years; 66% male; 37% ischemic heart disease). During a median follow-up of 48.2 months (IQR 48.9), 585 echocardiograms were performed. The mean LVESV reduced from 173±72ml before CRT-D implantation to 100±43ml at 6 months follow-up (P<0.001). The reduction in LVESV remained preserved long term (Figure 1; columns). However, increase in LVESV during long-term follow-up was an independent predictor of ICD shock (adjusted HR 1.014; 95% CI 1.006 - 1.022; P=0.001), thus LVESV increase of 50ml was associated 2.0 times higher risk of ICD shock.
Conclusion: LV reverse remodelling in super-responders to CRT remains preserved during long term follow up. However, increase in LVESV during follow-up is an independent predictor for ICD shock.
- © 2013 by American Heart Association, Inc.