The Role of Implantable Cardioverter-Defibrillators in Patients With Continuous Flow Left Ventricular Assist Devices
What is the role of implantable cardioverter-defibrillators (ICDs) in patients with a continuous flow left ventricular assist device (cfLVAD)?
A total of 106 patients at a single implanting institution with a HeartMate II (HMII) cfLVAD were studied between June 2008 and April 2012. Patients were followed until they reached one endpoint: death, transplantation, HMII explantation, end of follow-up period, or loss to follow-up. Ventricular arrhythmias (VAs) were defined as early if occurring <30 days after HMII implantation or late if >30 days after implantation. ICDs were deactivated at time of LVAD implantation and reactivated postoperatively. Those without an ICD or who had their ICD inactivated or explanted post-LVAD were placed in the no ICD group.
Eighty-two percent of the patients who received an HMII were male, 57.5% had nonischemic cardiomyopathy, and 87.7% received an HMII as bridge to transplantation. Mean age was 56.6 ± 11.4 years, mean LV ejection fraction was 18.4 ± 7.2%, and the median support time was 217 days. 78.3% of patients had an ICD and 45.4% had a history of VAs pre-LVAD implantation. 34.9% of patients developed VAs, with no significant difference between those with early versus late VAs. There were no episodes of sudden cardiac death and VAs were not associated with increased mortality post-LVAD (hazard ratio, 0.58 [0.18-1.90]). An appropriate shock was delivered in 27.3% of patients; however, the presence of an ICD was not associated with improved survival (hazard ratio, 1.12 [0.37-3.5]).
The authors concluded that VAs are common in patients with cfLVADs, but are not associated with increased mortality. Although ICDs deliver appropriate therapy, they are not associated with improved survival in this population.
The effect of VAs on mortality with cfLVADs has been variable in prior studies; however, this study favors that VAs post-cfLVAD do not significantly influence mortality. Not many studies have examined the effect of ICDs in cfLVAD patients. This study supports that ICDs in cfLVAD patients may not reduce mortality. The question of cost-effectiveness of ICDs in cfLVAD patients becomes relevant, and larger studies are needed to address this.
Keywords: Heart Diseases, Tachycardia, Ventricular, Follow-Up Studies, Cardiomyopathies, Heart Failure, Cardiovascular Physiological Phenomena, Death, Sudden, Cardiac, Pain Measurement, Defibrillators, Implantable
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