Implantable Cardioverter Defibrillators and Survival in Continuous-Flow Left Ventricular Assist Device Patients

Active Implantable cardioverter-defibrillators in Continuous-flow Left Ventricular Assist Device Recipients

Introduction

Implantable cardioverter-defibrillator (ICD) in patients with heart failure with reduced ejection fraction reduces mortality secondary to malignant arrhythmias. Whether end-stage heart failure (HF) with continuous-flow left ventricular assist device (cf-LVAD) derive similar benefits remains controversial.

Methods

We performed a systematic literature review and meta-analysis of all published studies that examined the association between active ICDs and survival in advanced HF patients with cfLVAD. We searched PubMed, Medline, Embase, Ovid, and Cochrane for studies reporting the association between ICD and all-cause mortality in advanced HF patients with cfLVAD. Mantel-Haenszel risk ratio (RR) random-effects model was used to summarize data.

Results

Ten studies (9 retrospective and one prospective) with a total of 7,091 patients met inclusion criteria. There was no difference in all-cause mortality (RR 0.84, 95% CI 0.65-1.10, p=0.20, I² =62.40%), likelihood of survival to transplant (RR 1.07, 95% CI 0.98-1.17, p= 0.13, I² =0%), RV failure (RR 0.74, 95% CI 0.44-1.25, p = 0.26, I² =34%) between Active ICD and inactive/no ICD groups, respectively. Additionally, 27.5% received appropriate ICD shocks, while 9.5% received inappropriate ICD shocks. No significant difference was observed in terms of any complications between the two groups.

Conclusions

All-cause mortality, the likelihood of survival to transplant, and worsening RV failure were not significantly different between active ICD and inactive/no ICD in cf-LVAD recipients. A substantial number of patients received appropriate ICD shocks suggesting a high-arrhythmia burden. The risks and benefits of ICDs must be carefully considered in patients with cf-LVAD.

Cardiovascular implantable electronic device therapy in patients with left ventricular assist devices: insights from TRAViATA

BACKGROUND

There is conflicting observational data on the survival benefit cardiac implantable electronic devices (CIED) in patients with LVADs.

METHODS

Patients in whom an LVAD was implanted between January 2008 and April 2017 in the multinational Trans-Atlantic Registry on VAD and Transplant (TRAViATA) registry were separated into four groups based on the presence of CIED prior to LVAD implantation: none (n = 146), implantable cardiac defibrillator (ICD) (n = 239), cardiac resynchronization without defibrillator (CRT-P) (n = 28), and CRT with defibrillator (CRT-D) (n = 111).

RESULTS

A total of 524 patients (age 52 years ±12, 84.4% male) were followed for 354 (interquartile range: 166-701) days. After multivariable adjustment, there were no differences in survival across the groups. In comparison to no device, only CRT-D was associated with late right ventricular failure (RVF) (hazard ratio 2.85, 95% confidence interval [CI] 1.42-5.72, p = 0.003). There was no difference in risk of early RVF across the groups or risk of ICD shocks between those with ICD and CRT-D.

CONCLUSION

In a multinational registry of patients with LVADs, there were no differences in survival with respect to CIED subtype. However, patients with a pre-existing CRT-D had a higher likelihood of late RVF suggesting significant long-term morbidity in those with devices capable of LV‑lead pacing post LVAD implantation.

Case report: incessant ventricular fibrillation in a conscious left ventricular assist device patient

Background 

Ventricular arrhythmia in left ventricular assist device (LVAD) recipients represents a challenging clinical scenario and the optimal treatment strategy in this unique patient population still needs to be defined.

Case summary 

We report on a 61-year-old LVAD patient with incessant ventricular fibrillation (VF) despite multiple unsuccessful attempts to restore normal rhythm with external defibrillation and antiarrhythmic medication. He remained initially stable as an outpatient and subsequently developed secondary organ failure.

Discussion 

This case demonstrates that under LVAD support long-term haemodynamic stability is possible even in case of VF, a situation that resembles Fontan circulation. However, ventricular arrhythmias are associated with a high risk of secondary organ damage due to right heart failure if left untreated. In case of refractory ventricular tachycardia or electrical storm listing for heart transplantation with high priority status should be pursued when possible. Alternatively, catheter ablation may be considered in selected cases and be performed in experienced centres in close collaboration with all involved specialists.

Implantable cardioverter defibrillators in left ventricular assist device patients: Α systematic review and meta-analysis

Implantable cardioverter-defibrillators (ICDs) remain the standard of care in advanced heart failure with reduced ejection fraction patients for the prevention of sudden cardiac death. However, current guidelines remain conflicting with respect to the use of ICDs in patients supported with a continuous flow left ventricular assist device (CF-LVAD). The current review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies comparing the use of ICD in patients with CF-LVADs were included. The 2 primary outcomes studied were all-cause mortality, and a successful bridge to heart transplantation. We calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs). We also compared baseline characteristics between US and European studies, for CF-LVAD patients with an ICD. Among all studies, the use of an ICD was not associated with all-cause mortality in patients with CF-LVADs (OR: 0.85, 95% CIs: 0.64-1.12, p = 0.24). The presence of an ICD was associated with a trend towards increased likelihood of successful bridge to heart transplantation (OR: 1.12, 95% CI: 1.0-1.3, p = 0.06). A subgroup analysis of studies published by European centers revealed a significant decrease in pooled mortality (OR: 0.58, 95% CI: 0.4-0.83, p = 0.003) with the use of ICD, contrary to an increase in pooled mortality among studies published by US centers (OR: 1.2, 95% CI 1.02-1.33, p = 0.025). Moreover, we identified significant differences in baseline characteristics such as bridge to transplantation rate, Interagency Registry for Mechanically Assisted Circulatory Support profiles, and use of an intra-aortic balloon pump or extracorporeal membrane oxygenation preoperatively, between the US and European populations. While this meta-analysis did not show an overall survival benefit with the use of an ICD in CF-LVAD patients, it revealed significant differences in the derived benefit, in distinct patient populations. This might reflect differences in baseline patient characteristics and warrants further investigation.

Leadless pacemaker use in a patient with a durable left ventricular assist device

There is limited known safety and efficacy of leadless pacemaker device use in patients with durable left ventricular assist devices (LVADs). We present a case of a pacemaker-dependent LVAD patient with infection of permanent transvenous pacemaker who underwent successful implantation of Micra transcatheter pacing system (Medtronic).

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.