Hospitalization for Heart Failure and Subsequent Ventricular Tachyarrhythmias in Patients With Left Ventricular Dysfunction.

OBJECTIVES

This study aimed to evaluate the risk of sustained life-threatening ventricular tachyarrhythmias (VTAs) after hospitalization for heart failure (HHF).

BACKGROUND

HHF is common among patients with an implantable cardioverter-defibrillator (ICD).

METHODS

We analyzed all 5,511 ICD patients enrolled in the landmark MADIT (Multicenter Automatic Defibrillator Implantation Trial) and RAID (Ranolazine in High-Risk Patients With Implanted Cardioverter-Defibrillator) trials. Multivariate Cox regression was used to evaluate the association of in-trial HHF occurrence with the risk of subsequent VTA and the composite end point of VTA or cardiac death.

RESULTS

Mean age was 64 ± 11 years, 23% were women, 62% were ischemic, and 40% had cardiac resynchronization therapy with defibrillators. The 3-year cumulative rate of VTA subsequent to HHF was significantly higher than the corresponding rate without HHF (44% vs. 24%, respectively; p < 0.001). After multivariable adjustment, time-dependent HHF was shown to be associated with a 79% increased risk for VTA and a 2.9-fold increased risk for VTA/cardiac death (p < 0.001 for both). In-trial development of atrial tachyarrhythmia (ATA) was also identified as an independent risk factor for the VTA and VTA/cardiac death end points (hazard ratio [HR]: 1.59 and 1.43, respectively; p ≤ 0.001 for both) but did not affect the association of HHF with VTA. Subgroup analysis demonstrated that the association of HHF with the risk of subsequent VTA was maintained among risk subsets categorized by age, sex, history of ATA, and implantation indication, but was significantly more pronounced among patients with nonischemic versus ischemic cardiomyopathy (HR: 2.54 and 1.43, respectively; p for interaction = 0.017).

CONCLUSIONS

HHF is a powerful risk factor for subsequent VTA in patients implanted with an ICD. These data may be used for improved risk stratification in this population.