The role of implantable cardioverter-defibrillators in patients with continuous flow left ventricular assist devices.

Background: The prognosis for patients experiencing ventricular arrhythmias (VAs) while on continuous flow left ventricular assist device (LVAD) support has not been well elucidated. Accordingly, the role of implantable cardioverter-defibrillators (ICDs) in this patient population remains undefined.

Methods And Results: Records of 106 consecutive patients undergoing implantation of the HeartMate II LVAD at a single center were reviewed. For patients surviving >30 days postimplant (98 patients), the impact of VAs and ICDs on survival was analyzed. Mean age was 56.6±11.4 years, 82.1% were male, 42.5% had an ischemic cardiomyopathy, 87.7% were bridge to transplantation, and median length of support was 217 days. Twenty-one (19.8%) patients died, 60 (56.6%) survived to transplantation, and 25 patients (23.6%) reached the end of study, had the LVAD explanted, or were lost to follow-up. Post-LVAD VAs occurred in 37 patients (34.9%) but were not associated with increased mortality (hazard ratio, 0.58 [0.18-1.90]). Sixty-two (63.3%) patients had an active ICD, and 36 (36.7%) patients had no ICD or an inactivated ICD post-LVAD. Patients with an ICD were more likely to be INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) level 3 or 4 at the time of implant (54.8% versus 33.3%; P=0.04). An appropriate shock was delivered in 27.3% of patients, but the presence of an active ICD was not associated with improved survival (hazard ratio, 1.12 [0.37-3.35]).

Conclusions: VAs are common in patients with continuous flow LVADs. Although some episodes may be clinically significant, VAs are not associated with a worse prognosis, and concomitant ICDs in these patients may not reduce mortality.