Cardiovascular Implantable Electronic Devices -> Monitoring & Outcomes: -> Monitoring & Follow-up D-PO05 - Poster Session V (ID 39) Poster

D-PO05-091 - Predictors Of Appropriate Therapies After Generator Replacement In Patients With A Primary Prevention Implantable Cardioverter Defibrillator: A Multicentre Experience (ID 544)

 L. Arcinas: Nothing relevant to disclose.
Audio File Upload


Background: Implantable Cardioverter Defibrillators (ICDs) are indicated for the primary prevention of sudden cardiac death in patients with reduced left ventricular ejection fraction (LVEF). Guidelines are based on trials with follow-up periods of 2-4 years. Contemporary ICDs have a lifespan of 4-7 years. The ongoing risk/benefit profile beyond this time span is unknown.
Objective: The purpose of this study was to explore if appropriate ICD therapies (shock and/or antitachycardia pacing) after generator replacement was predicted by a history of prior appropriate therapies and LVEF recovery at the time of replacement.
Methods: We identified a retrospective cohort of 219 consecutive patients who had a primary prevention ICD and a generator replacement between April 2005 and July 2015 at 3 centres in Canada. Recovery of LVEF was defined as LVEF > 35% and an increase of ≥10% from baseline. Predictors of appropriate therapies after replacement were explored by multiple logistic regression analysis.
Results: Baseline characteristics of the 219 patients were similar in those who received and did not receive ICD shocks after generator replacement. Over a median follow up of 2.2 years after generator replacement, 61 (28%) experienced appropriate shock while 40 (18%) experienced appropriate ATP. Only 1 of the 52 (2%) patients who had LVEF recovery received an ICD shock after replacement. Conversely, 60 of the 61 (98%) patients who had an ICD shock had no LVEF recovery. LVEF recovery was independently associated with a reduced risk of appropriate ICD therapy (ICD shock and/or ATP) after generator replacement (OR 0.4, 95% CI 0.3-0.6, p<0.001). Appropriate ICD shock and appropriate ATP prior to replacement were independently associated with a significantly increased risk of appropriate ICD therapy after generator replacement (OR 8.1, 95% CI 4.2 - 15.6, p<0.001 and OR 4.3 95% CI 2.3 - 8.3, p<0.001, respectively).
Conclusion: In primary prevention ICD patients who have had their first generator replacement, LVEF recovery is protective against future ICD shocks and ATP. Conversely, appropriate shocks and appropriate ATP prior to replacement are predictive of appropriate ICD therapies following generator replacement.