Role of Implantable Cardioverter-Defibrillators in Patients With Continuous Flow Ventricular Assist Devices

Abstract

The management of advanced heart failure has been transformed in the past 2 decades by the advent of cardiac implantable electronic devices, such as implantable cardioverter defibrillators (ICDs) and cardiac resynchronization therapy, and more recently the left ventricular assist device (LVAD). All 3 of these devices have been found to improve survival in patients with advanced heart failure.1–6 Cardiac resynchronization augments cardiac output by coordinating the timing of intrinsic muscular contraction to enhance its efficiency in patients with preexisting dyssynchrony. After LVAD placement, the contribution of native LV activity may be negligible, so that continued LV pacing likely does not significantly enhance cardiac function. However, LVAD recipients remain at high risk for ventricular arrhythmias (VAs) that may adversely affect right ventricular function, preload, and cardiac output. VAs (including ventricular fibrillation) are often tolerated for prolonged time periods in LVAD recipients, permitting patients to seek medical care when symptoms are present. In this setting, the incremental survival benefit of ICDs and LVADs in combination is not clear and, indeed, controversial. Enriquez et al7 report important data in this edition of Circulation Arrhythmia and Electrophysiology . This article is the largest study so far to examine this question in patients receiving the most commonly implanted LVAD at this time, and the only device Food and Drug Administration approved for bridge to transplant and destination therapy, the Heartmate II continuous flow device. Article see p 668 The investigators report the clinical outcomes and survival of a cohort of 106 patients, the majority of whom received an LVAD as bridge to cardiac transplantation. Patients surviving <30 days after implant were excluded, but are referenced separately in the article. After LVAD implantation, 36.7% of patients did not have …