**5. Evidence for implantable cardioverter defibrillator device**

The evidence that supports ICD indication in patients with LVAD is very limited, and current guidelines are based primarily on the consensus of experts and observational studies [13].

A meta-analysis by Vakil et al. showed that ICD therapy was associated with an absolute risk reduction of 16% and a relative risk reduction of 39% in all-cause mortality at a 7-month follow-up. The number of patients who needed to treat to avoid an outcome was six subjects [11]. Nevertheless, there is not any statistical significance in the continuous-flow LVAD subgroup (34% of the total population). The ICD cohort showed a mortality up to 14% vs. 25% in the non-ICD group (and an absolute risk reduction of 11% and a 24% relative risk (p = 0.17). The lack of significant results was

#### *Implantable Cardioverter-Defibrillator Use in Patients with Left Ventricular Assist Devices DOI: http://dx.doi.org/10.5772/intechopen.109396*

due to the small sample size due to the better long-term results and hemodynamic stability with new continuous-flow assistance [13] with less dependence on native cardiac activity than pulsatile pumps [28].

Rorris et al. did not find any difference in all-cause mortality events, cardiovascular mortality, or right heart failure between LVAD patients with and without an ICD. Although, the study finds important differences in baseline patient characteristics between European and United States populations [29].

A subanalysis of the INTERMACS Registry that included of 2209 patients with an ICD and 2209 patients without one concluded that the presence of ICD was not related to reduced mortality, among patients with a continuous-flow LVAD. The presence of an ICD was associated with increased mortality risk and unexpected death during device support because of the result of propensity score matching, which resulted in an ICD group that had decreased prevalence of certain VD risk factors (as beta-blocker or amiodarone use, prior to VD, or chronic HF) [28].

Kutyfa et al. demonstrated that neither implant ICD before nor after LVAD reached significant survival benefit in a 191-patient study after 23 months of follow-up [30].

Younes et al. designed a 1444 patients study included in a waitlist HF bridged to transplant with LVAD. These authors suggested that the presence of ICD was not associated with lower mortality, cardiovascular or global mortality, or delisting although arrhythmic death was more common in the non-ICD group compared with ICD [12, 31].

A 94-patient study about the use of ICD after continuous-flow LVAD implant showed that only patients with VD before LVAD placement had any benefit [19]. Therefore, it is reasonable to not implant ICD in LVAD patients without previous VD [20].

Alvarez et al. [3] studied 487 patients, mostly with ICDS, 79.6%. The presence of ICD before LVAD was not related to a significant benefit in terms of mortality. However, ICD patients before LVAD presented complications such as episodes of shocks (31%), ventricular lead dysfunction (4.6%), and 2% of infections associated with ICD [3, 32].

The high rates of inappropriate shocks and infection events may decrease the benefits of the ICD indication [5]. Indeed, ICD shocks are associated with worse long-term outcomes and poorer quality of life and can negatively affect mental status [33]. Patients experience inappropriate shocks due to supraventricular tachycardias or electromagnetic interference; for that reason; benefit of appropriate shocks for prolonged but hemodynamically critical VD remains unclear [12].

Infection is a frequent complication in the LVAD population (i.e., driveline infection or device-related sepsis) that can occur in up to 20% of patients. Malnutrition and high comorbidity including diabetes, surgical technique, and quality of percutaneous lead care are important risk factors for infection. Aggressive management often is needed including long-term antibiotics, device exchange, or even urgent transplants [4]. Therefore, infection treatment could be more complex in the presence of both devices (LVAD and ICD).

Riaz et al. described a cohort of 215 ICD-LVAD patients and six (2.8%) developed ICD infections. Three patients had pocket infections related to device generator exchange, and three patients had ICD lead-related endocarditis due to prior LVADrelated infections. In all cases, ICD was removed along with antibiotics. Three patients with a history of previous LVAD infections received longer antimicrobial therapy, and one patient had their LVAD exchanged [32].

Finally, at the last 2019 EACTS Expert Consensus on long-term mechanical circulatory support [34] indications are: (i) patients with LVAD who develop postoperative ventricular dysrhythmias associated with hemodynamic collapse, ICD implantation is


#### **Table 1.**

*Summary of current guidelines about the use of implantable cardioverter defibrillator devices in the LVAD population.*

recommended (IC); (ii) patients who have an ICD implanted before LVAD, it should be kept activated for prevention of adverse effects due to right ventricular dysfunction, but its programming should be very conservative (IIaC); (iii) primary prevention is not recommended in patients without VD before LVAD (IIIC).

On the other hand, the 2022 ESC Guidelines for the management of patients with ventricular dysrhythmias and the prevention of sudden cardiac death [35] recommends: ICD implantation should be considered in LVAD recipients with symptomatic sustained VD (IIaB) **Table 1**.
