Abstract 328: Patients with Left Ventricular Function Improvement After Biventricular ICD Implantation Have a Persistent Risk of Ventricular Tachycardia or Fibrillation
Background: Ventricular arrhythmias such as Ventricular Tachycardia (VT) or Fibrillation (VF) are the leading causes of mortality in patients with advanced heart failure. The biventricular implantable cardioverter defibrillator (BiV- ICD) has evolved as a means of treating heart failure because it provides therapy for VT/VF as well as an improvement in left ventricular (LV) function by increasing left ventricular ejection fraction (LVEF). This study analyzed the risk of ventricular arrhythmias after BiV- ICD implantation in patients with improved LVEF versus those without improvement.
Methods: This is a retrospective study of 168 patients who were divided into two groups based on whether the LVEF improved after device implantation. Therapy was defined as shock or antitachycardic pacing (ATP) that terminates the ventricular arrhythmia. We determined patients characteristics based on ischemic, non-ischemic heart failure groups.
Results: Of all the patients with a BiV - ICD, 51% had improvement in their LVEF. Of the ischemic group, 41% had improved EF compared to 63% in the nonischemic group (p=0.005). A total of 29 patients received electrical therapy for VT/VF. Of the patients with improved LVEF, 14 (16%) were shocked compared to 15 patients (18%) in the group with no improvement in LVEF (P =0.730). At 1year, the difference in therapy was not significant between the ischemic (10%) and nonischemic (14%) groups (p=0.706). This same effect was observed up until 9.2 years (0.778). Patients on antiarrhythmic medications received more shocks (13.6% vs. 16.5%) compared to those not on any antiarrhythmic medications (p=0.039). There was no difference in mortality between the groups whether assessed according to ischemic, nonischemic (1.2% vs 6.9%) or improved, nonimproved EF status (1.2% vs. 7.3%) (P=0.095).
Conclusion: Improved LVEF after BiV-ICD implantation was not associated with lower likelihood of receiving therapy for VT/VF. There was no difference in electrical therapies in ischemic compared to non-ischemic HF. There was no difference in mortality between the groups after BiV-ICD implantation.
- Advancing heart failure
- Bi-ventricular pacing
- Ventricular tachycardia
- Ventricular fibrillation
- Ejection fraction
Author Disclosures: A. Joseph: None. T. Matthews-Hew: None. M. Dakkak: None. S. Hsu: None. C. Gist: None.
- © 2014 by American Heart Association, Inc.