Risk of ventricular arrhythmias following implantable cardioverter‐defibrillator generator change in patients with recovered ejection fraction: Implications for shared decision‐making

Abstract

Introduction: Guidelines indicate primary-prevention implantable cardioverterdefibrillators (ICDs) for most patients with left ventricular ejection fraction (LVEF) ≤ 35%. Some patients' LVEFs improve during the life of their first ICD. In patients with recovered LVEF who never received appropriate ICD therapy, the utility of generator replacement upon battery depletion remains unclear. Here, we evaluate ICD therapy based on LVEF at the time of generator change, to educate shared decision-making regarding whether to replace the depleted ICD. Methods:We followed patients with a primary-prevention ICD who underwent generator change. Patients who received appropriate ICD therapy for ventricular tachycardia or ventricular fibrillation (VT/VF) before generator change were excluded. The primary endpoint was appropriate ICD therapy, adjusted for the competing risk of death.Results: Among 951 generator changes, 423 met inclusion criteria. During 3.4 ± 2.2 years follow-up, 78 (18%) received appropriate therapy for VT/VF. Compared to patients with recovered LVEF > 35% (n = 161 [38%]), those with LVEF ≤ 35% (n = 262 [62%]) were more likely to require ICD therapy (p = .002; Fine-Gray adjusted 5-year event rates: 12.7% vs. 25.0%). Receiver operating characteristic analysis revealed the optimal LVEF cutoff for VT/VF prediction to be 45%, the use of which further improved risk stratification (p < .001), with Fine-Gray adjusted 5-year rates 6.2% versus 25.1%. Conclusion:Following ICD generator change, patients with primary-prevention ICDs and recovered LVEF have significantly lower risk of subsequent ventricular arrhythmias compared to those with persistent LVEF depression. Risk stratification at LVEF 45% offers significant additional negative predictive value over a 35%

To Replace or Not to Replace: What to do with the implantable cardioverter-defibrillator generator when the left ventricular function has improved

“…However, none of the prior studies assessed the risk of ICD therapy using an EF cutoff 45% and none provided event rates adjusted for the competing risk of mortality. As such, the study by Chang et al 5 advances the field significantly. Do ICDs save lives if the EF has improved to [?]35%?…”

To replace or not to replace: What to do with the implantable cardioverter‐defibrillator generator when the left ventricular function has improved

“…However, none of the prior studies assessed the risk of ICD therapy using an EF cutoff 45% and none provided event rates adjusted for the competing risk of mortality. As such, the study by Chang et al 5 advances the field significantly.…”

“…The field continues to evolve. In this regard, data from the study by Chang et al 5 will be very valuable, to facilitate the discussion between patients and their physicians.…”

“…In this issue of the journal, Chang et al present the results of a retrospective cohort study evaluating the risk of appropriate ICD therapies in 423 patients who underwent ICD generator replacement. 5 Notably, all ICDs were implanted for primary prevention of SCD and no patient had received appropriate ICD therapies in the past. The analyses were adjusted for competing risk of death.…”

“…However, none of the prior studies assessed the risk of ICD therapy using an EF cutoff 45% and none provided event rates adjusted for the competing risk of mortality. As such, the study by Chang et al 5 Ideally, the possibility of not replacing the ICD generator when the device reaches ERI should be introduced at the initial implantation.…”