Abstract 15967: Risk of Ventricular Tachyarrhythmias Following Ejection Fraction Improvement in Patients With Implantable Cardiac Defibrillators Implanted for Primary Prevention of Sudden Cardiac Death
Introduction: In patients who undergo cardiac device (ICD) implantation for primary prevention of sudden cardiac death (SCD), data is unclear if their generator needs to be replaced at end of life if their ejection fraction improves. Despite improvement in EF however, the underlying scar may remain the same.
Methods: A retrospective study was performed at two high volume centers. Data on 280 patients who underwent ICD implantation for primary prevention of SCD was obtained after excluding patients with incomplete follow-up data. These patients were followed until November 2013 for any improvement in EF and if they underwent a generator change at device ERI. All arrhythmic events and appropriate and inappropriate shocks/ATP were all recorded. Mortality records were obtained from social security death index and chart review.
Results: Thirty percent (n=86/280) of patients improved their EF to > 35% of which 41% (n=36) underwent a generator change by the study ending period for ERI/lead malfunction/infection issues with the rest not yet at ERI. Mean baseline EF in patients with and without EF improvement was 26±7% and 23±7%, p=0.2. Data for arrhythmic events was unavailable in n=25 patients in those with EF improvement and n =39 patients in those without EF improvement. Among the remaining 61 patients, appropriate events (shock+ATP) were noted in 22% of patients (n=14/61) and inappropriate shocks and ATP in 6% of (n=4/61) patients after their EF improved to > 35%. Two patients received a prior shock when their EF was low. In contrast, in patients who had no improvement in EF, 31% (n=48/155) received an appropriate event (p=<0.01) while 14% (n=22/155) (p<0.02) received inappropriate shocks and ATP. All-cause mortality in patients without subsequent improvement in EF versus those with EF improvement (38% vs. 17% (p=.006). Mean time to EF improvement was 44±35 months and mean duration of follow-up since EF improvement was 38±27 months.
Conclusions: Although patients with improvement in EF had fewer total events (ATP+shock) than those without improvement, the percentage of patients with ICD therapy post EF improvement with no prior ICD discharges is high enough (20%, n=12/59) to warrant an ICD despite EF improvement.
Author Disclosures: J. Pillarisetti: None. R. Gopinathannair: None. M. Haney: None. M. Reddy: None. S. Reddy: None. M. Khalafi: None. A. Kanmantha Reddy: None. N. Adabala: None. V. Yarlagadda: None. S. Bommana: None. D. Lakkireddy: None.
- © 2014 by American Heart Association, Inc.