Background:
In patients with advanced heart failure and reduced ejection fraction, the use of implantable cardioverter defibrillators (ICD) for prevention of sudden cardiac death is standard of care. In addition, for end-stage heart failure left ventricular assist devices (LVAD) are used as either bridge to heart transplantation or destination device. Evidence on ICD device complications in this population remain scarce.

Methods:
We analyzed all LVAD patients that underwent ICD-follow up in our heart center until November 2022. Data were screened for any generator or lead related complications of the ICD.

Results:
In total, 46 patients had an ICD and a LVAD implanted. The mean age at LVAD implantation was 60.1 ± 7.5 years, 93.4% were males (n=43) and 50% had ischaemic heart disease (n=23). At LVAD implantation 50% had a CRT-D (n=23), 28.3% a VVI-ICD (n=13), 19.6% a DR-ICD (n=9) and 2.2% a S-ICD (n=1) implanted. The endpoint was successful bridge to heart transplantation, explantation of the LVAD or death. In the follow up period 14 patients underwent a heart transplantation, 1 underwent LVAD explantation due to an infection and 6 patients died during follow up. 24 patients still had a LVAD implanted at the end of the screening period. One patient dropped out of the follow up after 45 months because he moved away. 

The mean follow up duration was 46.3 months. In this period 73.9% of the patients (n=34) had no complications. 8 of the 34 patients underwent regular generator replacement without any further complications.
There were unexpected complications in 26.1% (n=12). Seven patients experienced changes in sensing, pacing threshold or impedance of the right ventricular (RV) or left ventricular (LV) lead. Most common was a rise in the LV pacing threshold that led to a deactivation of the LV lead (n=3). One of those patients later also developed an exit block and a drop in the impedance of the RV lead, the impedance of the defibrillation lead remained unchanged. In three cases, the sensing of the RV and the LV lead worsened after LVAD implantation. In one case, there was a significant rise in the pacing threshold of the RV lead. None of those complications led to a lead revision or replacement.

In two cases, the routine check-up was not possible anymore due to interaction between the LVAD and the generator. In 4 cases, there was an infection that led to complete explantation of the ICD system. One of those patients received a new ICD. The three patients without ICD-reimplantion did not experience any life-threatening arrhythmias. 

Conclusion:
Generator and lead complications are frequent in LVAD patients. However, in most cases complications can be handled conservatively. Particularly, for LV lead problems deactivation of the LV lead seems to be a safe approach since there is no proven benefit of LV pacing in LVAD patients. Revisions of the RV lead should only be performed if there are disturbed defibrillation function or pacemaker dependency. Complete explantation of the ICD system is recommended for device or lead infections. The benefit of ICD re-implantation remains unknown and should only be performed after careful consideration.

Possible interactions between LVAD and ICD devices should be considered and device interrogation can be challenging.