Time for MADIT-VAD?

Implantable Cardioverter Defibrillators in Patients With Continuous Flow Left Ventricular Assist Devices: Utilization Patterns, Related Procedures, and Complications

Background

The effect of implantable cardioverter defibrillators (ICD) in patients with continuous flow left ventricular assist devices (LVADs) on outcomes has not been evaluated in a randomized clinical trial.

Methods and Results

This is a retrospective single‐center study that included patients who underwent continuous flow LVAD implantation at the Cleveland Clinic between October 2004 and March 2017. Patients were evaluated according to the presence or absence of ICD at the time of LVAD insertion. Among 486 patients in the study cohort, 387 (79.6%) had an ICD before LVAD insertion. Patients with ICD before LVAD were older and had lower use of pre‐LVAD inotropes, extracorporeal membrane oxygenation, and mechanical ventilation. There were 81 patients (21.4% of patients with ICD) who required 93 procedures after LVAD: 74 generator exchanges, 12 lead revisions, and 7 complete system removals because of infection. Of the 99 patients without ICD, 52 (53%) underwent ICD implantation: 29 for primary prevention and 23 for secondary prevention. Patients were followed for a median of 401 (interquartile range 150–966) days. The presence of a pre‐LVAD ICD was not associated with mortality in a multivariable model (hazard ratio 1.19, 95% CI 0.73–1.93, P=0.492), nor was the presence of an ICD at any point when analyzed as a time‐varying covariate (hazard ratio 1.05, 95% CI 0.50–2.20, P=0.907).

Conclusions

There is no apparent mortality benefit associated with an ICD in a contemporary cohort of patients with continuous flow LVADs to balance considerable morbidity involving ICD‐related procedures and complications.

Implantable cardioverter-defibrillators and survival in advanced heart failure patients with continuous-flow left ventricular assist devices: a systematic review and meta-analysis

Aims

Implantable cardioverter-defibrillators (ICDs) implantation in heart failure (HF) patients with reduced ejection fraction improves survival by reducing mortality secondary to arrhythmic events. Whether advanced HF patients treated with continuous-flow left ventricular assist devices (CF-LVADs) derive similar benefit is controversial.

Methods and results

We searched PubMed, Cochrane Central Register of Controlled Trials, Embase, and Scopus from inception through November 2018 for studies examining the association between ICD implantation and all-cause mortality in patients with advanced HF and CF-LVADs. Analyses were performed using a random-effects model. Hazard ratios (HRs) were calculated with 95% confidence intervals (CIs). Heterogeneity and publication bias were formally assessed, using I2 and funnel plots, respectively. Eight observational studies with a total of 6416 patients (ICD group = 3450, no ICD group = 2966) met inclusion criteria. The majority of patients (84.6%) came from the two largest observational studies. There was no difference in mortality in the ICD and no ICD groups (HR 0.96, 95% CI 0.73–1.27, P = 0.79, I2 = 42%), and ICD implantation post-CF-LVAD was not associated with an improvement in mortality (HR 0.87, 95% CI 0.48–1.57, P = 0.64, I2 = 0%). Additionally, there was no significant difference in the likelihood of transplantation (HR 1.10, 95% CI 0.93–1.30, P = 0.28, I2 = 26%) or non-mortality adverse events between the two groups.

Conclusion

Implantable cardioverter-defibrillator use was not associated with improved survival in advanced HF patients with CF-LVADs. These findings underscore the need to formally study the efficacy of ICDs in this population in a dedicated randomized controlled study.

Prospective Randomized Evaluation of Implantable Cardioverter-Defibrillator Programming in Patients With a Left Ventricular Assist Device

BACKGROUND

Ventricular arrhythmias are common in patients with left ventricular assist devices (LVADs) but are often hemodynamically tolerated. Optimal implantable cardioverter defibrillator (ICD) tachy-programming strategies in patients with LVAD have not been determined. We sought to determine if an ultra-conservative ICD programming strategy in patients with LVAD affects ICD shocks.

METHODS AND RESULTS

Adult patients with an existing ICD undergoing continuous flow LVAD implantation were randomized to standard ICD programming by their treating physician or an ultra-conservative ICD programming strategy utilizing maximal allowable intervals to detection in the ventricular fibrillation and ventricular tachycardia zones with use of ATP. Patients with cardiac resynchronization therapy (CRT) devices were also randomized to CRT ON or OFF. Patients were followed a minimum of 6 months. The primary outcome was time to first ICD shock. Among the 83 patients studied, we found no statistically significant difference in time to first ICD shock or total ICD shocks between groups. In the ultra-conservative group 16% of patients experienced at least one shock compared with 21% in the control group (P=0.66). There was no difference in mortality, arrhythmic hospitalization, or hospitalization for heart failure. In the 41 patients with CRT ICDs fewer shocks were observed with CRT-ON but this was not statistically significant: 10% of patients with CRT-ON (n=21) versus 38% with CRT-OFF (n=20) received shocks (P=0.08).

CONCLUSIONS

An ultra-conservative programming strategy did not reduce ICD shocks. Programming restrictions on ventricular tachycardia and ventricular fibrillation zone therapy should be reconsidered for the LVAD population. The role of CRT in patients with LVAD warrants further investigation.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01977703.