Objectives This study sought to determine if the presence of implantable cardioverter-defibrillators (ICD) provided a mortality benefit during continuous-flow left ventricular assist device (LVAD) support. Background An ICD decreases mortality in selected patients with advanced heart failure and have been associated with reduced mortality in patients with pulsatile LVAD. However, it is unclear whether that benefit extends to patients with a contemporary continuous-flow LVAD. Methods Propensity score matching was used to generate a cohort of patients with similar baseline characteristics. The primary outcome was freedom from death during LVAD support. Secondary endpoints included freedom from unexpected death, likelihood of transplantation and recovery, and adverse events. Results Among 16,384 eligible patients in the Interagency Registry for Mechanically Assisted Circulatory Support registry, 2,209 patients with an ICD and 2,209 patients without one had similar propensity scores and were included. The presence of an ICD was associated with an increased mortality risk (hazard ratio: 1.20; 95% confidence interval [CI]: 1.04 to 1.39; p = 0.013) and an increased risk of unexpected death during device support (HR: 1.33; 95% CI: 1.03 to 1.71; p = 0.03). Patients with an ICD were more likely to undergo transplantation (HR: 1.16; 95% CI: 0.99 to 1.35; p = 0.06) and less likely to have LVAD explant for recovery (HR: 0.53, 95% CI: 0.29 to 0.98; p = 0.04). Patients with an ICD had a higher rate of treated ventricular arrhythmias (rate ratio: 1.27; 95% CI: 1.10 to 1.48; p = 0.001) and rehospitalization (rate ratio: 1.08; 95% CI: 1.04 to 1.12; p < 0.0001), but rates of hemorrhagic stroke were similar (rate ratio: 1.01; 95% CI: 0.81 to 1.26; p = 0.98). Conclusions Among patients with a continuous flow LVAD, the presence of an ICD was not associated with reduced mortality.
Bibliographical noteFunding Information:
Data for this study were obtained from the INTERMACS registry, funded by the National Heart, Lung and Blood Institute, National Institutes of Health, Department of Health and Human Services under Contract No. HHSN268201100025C. The INTERMACS registry is a prospective national registry of more than 19,000 patients supported with U.S. Food and Drug Administration–approved durable mechanical circulatory support devices and has previously been described elsewhere ). Patients who received a biventricular assist device at time of implantation, right ventricular (RV) assist device only, or total artificial heart were excluded from the analysis. Similarly, patients with an unknown ICD status, pulsatile device, and those receiving their second LVAD were excluded. Patients were analyzed from the date of LVAD implantation to transplant, death, or device explant for recovery. The primary outcome was freedom from death while on LVAD support. Secondary endpoints included freedom from unexpected death, likelihood of transplantation and recovery, and adverse events including arrhythmia, stroke (hemorrhagic), and infection. Pre-specified subgroup analyses were performed for patients who were suspected to derive the greatest benefit from an ICD. (10) . The INTERMACS Data and Clinical Coordinating Center and each participating institution have received institutional review board/ethics review board approval for either active informed consent or a waiver of consent to enroll participants, link data, and perform analytic studies. All procedures are compliant with the Health Insurance Portability and Accountability Act, and INTERMACS has received a Federal Certificate of Confidentiality and other protection for the identities of patients and devices identified within the Registry. Analysis of the INTERMACS registry was performed for all patients who received a CF-LVAD between June 1, 2006, and June 30, 2016. There were 18,733 adult candidates (age ≥18 years) who received a durable CF-LVAD ( Figure 1
- heart failure
- implantable cardioverter-defibrillator
- left ventricular assist device