Abstract 8158: Prior Incidence of Ventricular Tachyarrhythmias Predict Subsequent Episodes of Ventricular Tachyarrhythmias and Increased Mortality in Subjects with Mildly Reduced Ejection Fraction on Cardiac Resynchronization Therapy -A MADIT study analysis

Abstract

Background: An incidence of ventricular tachyarrhythmia (VA)(including ventricular tachycardia and ventricular fibrillation) in a patient with reduced ejection fraction is a marker of increased all-cause mortality. We aimed to assess the impact of prior VAs on clinical outcomes in patients with mild heart failure symptoms who received cardiac resynchronization therapy with a defibrillator (CRT-D). Methods: We evaluated benefit of CRT-D vs. ICD-only therapy in the reduction of ventricular tachyarrhythmias or death by the presence of a history of VA among 1820 patients enrolled in the MADIT-CRT trial. Results: A history of VA was a significant risk factor for the occurrence of VT/VF or death during the trial (HR 2.06, 95% CI 1.55-2.74, p<0.001). Multivariate analysis showed that CRT-D therapy was associated with a significant reduction in the risk of ventricular tachyarrhytmias among patients without a history of VA, whereas risk-reduction associated with CRT-D therapy was not statistically significant among patients with a history of prior VA (Table). Conclusions: Our findings suggest that a history of prior VA is a powerful risk factor for the development of subsequent ventricular tachyarrhythmias and mortality among patients with mild CHF symptoms who receive device therapy. The benefit of CRT-D therapy appears to be attenuated among patients with prior VA.