Evaluation of the need of elective implantable cardioverter-defibrillator generator replacement in primary prevention patients without prior appropriate ICD therapy

Appropriate Implantable Cardioverter-Defibrillator Therapy in Patients with Ventricular Arrhythmia of Unclear Cause in Secondary Prevention of Sudden Cardiac Death

In this study, we sought to investigate the occurrence of appropriate implantable cardioverter-defibrillator (ICD) therapies and inappropriate shocks in secondary prevention ICD recipients with ventricular arrhythmia of unclear cause and ventricular arrhythmia in the context of underlying heart disease. In this retrospective study, consecutive patients with an ICD implanted for secondary prevention in the University Medical Center Groningen (UMCG), the Netherlands between 1 January 2012 and 31 December 2018 were included. Patients were classified as having ventricular arrhythmia of unclear cause if no clear cause was found which could explain the index ventricular arrhythmia. The primary outcome was appropriate ICD therapy. The study population consisted of 257 patients. In 220 patients, an underlying heart disease could be identified as the cause of ventricular arrhythmia, while 37 patients had an unclear cause of ventricular arrhythmia. The median age was 64 years (interquartile range (IQR) 53-72 years). Forty-five (18%) patients were women. During a median duration of follow-up of 6.2 years (IQR 4.8-7.8 years), appropriate ICD therapy occurred in 95 (37%) patients. This number was 90 (41%) in the group with a clear etiology and 5 (14%) in the group with an unclear etiology. In multivariable analysis, index ventricular arrhythmia of unclear cause was associated with fewer appropriate ICD therapies (HR 0.37 [95% CI 0.14-0.99]; p = 0.048), as well as an increased risk of inappropriate ICD shocks (HR 3.71 [95% CI 1.17-11.80]; p = 0.026). Index ventricular arrhythmia of unclear cause was significantly associated with fewer appropriate ICD therapies.

Incidence and Predictors of Implantable Cardioverter-defibrillator Therapies After Generator Replacement-A Pooled Analysis of 31,640 Patients' Data

Among primary prevention implantable cardioverter-defibrillator (ICD) recipients, 75% do not experience any appropriate ICD therapies during their lifetime, and nearly 25% have improvements in their left ventricular ejection fraction (LVEF) during the lifespan of their first generator. The practice guidelines concerning this subgroup's clinical need for generator replacement (GR) remain unclear. We conducted a proportional meta-analysis to determine the incidence and predictors of ICD therapies after GR and compared this to the immediate and long-term complications. A systematic review of existing literature on ICD GR was performed. Selected studies were critically appraised using the Newcastle-Ottawa scale. Outcomes data were analyzed by random-effects modeling using R (R Foundation for Statistical Computing, Vienna, Austria), and covariate analyses were conducted using the restricted maximum likelihood function. A total of 31,640 patients across 20 studies were included in the meta-analysis with a median (range) follow-up of 2.9 (1.2-8.1) years. The incidences of total therapies, appropriate shocks, and anti-tachycardia pacing post-GR were approximately 8, 4, and 5 per 100 patient-years, respectively, corresponding to 22%, 12%, and 12% of patients of the total cohort, with a high level of heterogeneity across the studies. Greater anti-arrhythmic drug use and previous shocks were associated with ICD therapies post-GR. The all-cause mortality was approximately 6 per 100 patient-years, corresponding to 17% of the cohort. Diabetes mellitus, atrial fibrillation, ischemic cardiomyopathy, and the use of digoxin were predictors of all-cause mortality in the univariate analysis; however, none of these were found to be significant predictors in the multivariate analysis. The incidences of inappropriate shocks and other procedural complications were 2 and 2 per 100 patient-years, respectively, which corresponded to 6% and 4% of the entire cohort. Patients undergoing ICD GR continue to require therapy in a significant proportion of cases without any correlation with an improvement in LVEF. Further prospective studies are necessary to risk-stratify ICD patients undergoing GR.

2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: Developed by the Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). With the special contribution of the Heart Failure Association (HFA) of the ESC

Document Reviewers: Rudolf A. de Boer (CPG Review Coordinator) (Netherlands), P. Christian Schulze (CPG Review Coordinator) (Germany), Magdy Abdelhamid (Egypt), Victor Aboyans (France), Stamatis Adamopoulos (Greece), Stefan D. Anker (Germany), Elena Arbelo (Spain), Riccardo Asteggiano (Italy), Johann Bauersachs (Germany), Antoni Bayes-Genis (Spain), Michael A. Borger (Germany), Werner Budts (Belgium), Maja Cikes (Croatia), Kevin Damman (Netherlands), Victoria Delgado (Netherlands), Paul Dendale (Belgium), Polychronis Dilaveris (Greece), Heinz Drexel (Austria), Justin Ezekowitz (Canada), Volkmar Falk (Germany), Laurent Fauchier (France), Gerasimos Filippatos (Greece), Alan Fraser (United Kingdom), Norbert Frey (Germany), Chris P. Gale (United Kingdom), Finn Gustafsson (Denmark), Julie Harris (United Kingdom), Bernard Iung (France), Stefan Janssens (Belgium), Mariell Jessup (United States of America), Aleksandra Konradi (Russia), Dipak Kotecha (United Kingdom), Ekaterini Lambrinou (Cyprus), Patrizio Lancellotti (Belgium), Ulf Landmesser (Germany), Christophe Leclercq (France), Basil S. Lewis (Israel), Francisco Leyva (United Kingdom), AleVs Linhart (Czech Republic), Maja-Lisa Løchen (Norway), Lars H. Lund (Sweden), Donna Mancini (United States of America), Josep Masip (Spain), Davor Milicic (Croatia), Christian Mueller (Switzerland), Holger Nef (Germany), Jens-Cosedis Nielsen (Denmark), Lis Neubeck (United Kingdom), Michel Noutsias (Germany), Steffen E. Petersen (United Kingdom), Anna Sonia Petronio (Italy), Piotr Ponikowski (Poland), Eva Prescott (Denmark), Amina Rakisheva (Kazakhstan), Dimitrios J. Richter (Greece), Evgeny Schlyakhto (Russia), Petar Seferovic (Serbia), Michele Senni (Italy), Marta Sitges (Spain), Miguel Sousa-Uva (Portugal), Carlo G. Tocchetti (Italy), Rhian M. Touyz (United Kingdom), Carsten Tschoepe (Germany), Johannes Waltenberger (Germany/Switzerland) All experts involved in the development of these guidelines have submitted declarations of interest. These have been compiled in a report and published in a supplementary document simultaneously to the guidelines. The report is also available on the ESC website www.escardio.org/guidelines For the Supplementary Data which include background information and detailed discussion of the data that have provided the basis for the guidelines see European Heart Journal online.

Ongoing Risk of Ventricular Arrhythmias and All-Cause Mortality at Implantable Cardioverter Defibrillator Generator Change: A Systematic Review and Meta-Analysis

[Figure: see text].

Incidence of appropriate implantable cardioverter-defibrillator therapy and mortality after implantable cardioverter-defibrillator generator replacement: results from a real-world nationwide cohort

Aims

The safety of omitting implantable cardioverter-defibrillator (ICD) generator replacement in patients with no prior appropriate therapy, comorbid conditions, and advanced age is unclear. The aim was to investigate incidence of appropriate ICD therapy after generator replacement.

Methods and results

We identified patients implanted with a primary prevention ICD (n = 4630) from 2007 to 2016, who subsequently underwent an elective ICD generator replacement (n = 670) from the Danish Pacemaker and ICD Register. The data were linked to other databases and evaluated the outcomes of appropriate therapy and death. Predictors of ICD therapy were identified using multivariate Cox regression analyses. A total of 670 patients underwent elective ICD generator replacement. Of these, 197 (29.4%) patients had experienced appropriate therapy in their 1st generator period. During follow-up of 2.0 ± 1.6 years, 95 (14.2%) patients experienced appropriate therapy. Predictors of appropriate therapy in 2nd generator period was low initial left ventricular ejection fraction (≤25%) [hazard ratio (HR) 1.87, confidence interval (CI) 1.13–1.95] and appropriate therapy in 1st generator period (HR 3.95, CI 2.57–6.06). For patients with appropriate therapy in 1st generator period, 4-year incidence of appropriate therapy was 50.6% vs. 16.4% in those without (P < 0.001). Among patients >80 years with no prior appropriate therapy 8.8% of patients experienced appropriate therapy after replacement. Comorbidity burden and advanced age were associated with reduced device utilization after replacement and a high competing risk of death without preceding appropriate therapy.

Conclusion

A significant residual risk of appropriate therapy in the 2nd generator was present even among patients with advanced age and with a full prior generator period without any appropriate ICD events.

Outcomes of patients with heart failure after primary prevention ICD unit generator replacement

OBJECTIVE

Data describing outcomes after implantable cardioverter-defibrillator (ICD) unit generator replacement in patients with heart failure (HF) with primary prevention devices are limited.

METHOD

Data on patients with HF who underwent primary prevention ICD/cardiac resynchronisation therapy-defibrillator (CRT-D) implantation from 2007 until mid-2015 who subsequently received unit generator replacement were analysed. Outcomes assessed were mortality, appropriate ICD therapy and shock, and procedural complications.

RESULTS

61 of 385 patients with HF with primary prevention ICD/CRT-D undergoing unit generator replacement were identified. Follow-up period was 1.8±1.5 years after replacement. 43 (70.5%) patients had not received prior appropriate ICD therapy prior to unit replacement. The cumulative risks of appropriate ICD therapy at 1, 3 and 5 years after unit replacement in those without prior ICD therapy were 0%, 6.2% and 50% compared with 6.2%, 59.8% and 86.6%, respectively (p=0.005) in those with prior ICD therapies. No predictive factors associated with appropriate ICD therapy after replacement could be identified. 41 (32.8%) patients no longer met guideline indications at the time of unit replacement but risks of subsequent appropriate ICD interventions were not different compared with those who continued to meet primary prevention ICD indications.The 5-year mortality risk after unit replacement was 18.4% and there were high procedural complication rates (9.8%).

CONCLUSION

No predictive marker successfully stratified patients no longer needing ICD support prospectively. Finding such a marker is important in decision-making about device replacement particularly given the concerns about the complication rates. These factors should be considered at the time of ICD unit replacement.

When Is It Safe Not to Reimplant an Implantable Cardioverter Defibrillator at the Time of Battery Depletion?

The implantable cardioverter defibrillator (ICD) is a life-saving therapy in various patient populations. Although data on the outcomes of initial ICD implants are abundant, data on ICD replacements, especially in patients with improved left ventricular (LV) function, are scarce. Therefore, it is not known when it is safe to not replace an ICD that has reached the end of battery life. This article reviews data on patients with primary prevention ICDs who have improvement in left ventricular ejection fraction during follow-up and provides some guidance, based on the available evidence, related to circumstances when replacement of an ICD may be forgone.

Reassessment of cardiovascular parameters and comorbidities in implantable cardioverter-defibrillator patients at the time of first replacement

BACKGROUND

Guidelines provide extensive recommendations regarding implantable cardioverter-defibrillator (ICD) implantation. However, ICD replacement at the time of battery depletion is rarely studied.

HYPOTHESIS

Our objectives were to identify patients at high-risk of death after ICD replacement, with a reassessment of changes in risk factors and comorbidities at the time of replacement, and to determine predictors for subsequent mortality.

METHODS

Patients undergoing ICD replacement for regular battery depletion were selected from a prospective single-center ICD registry. Both at implant and replacement, 3 demographic parameters, 9 cardiovascular parameters, 5 comorbidities, and 4 laboratory parameters were collected. Cox proportional hazard analyses were used.

RESULTS

We included 308 patients who were predominantly male (86%) with a median age at ICD replacement of 66 years. Replacement was performed 65 months (interquartile range, 52-91) after implantation. Median follow-up after replacement was 41 months, during which 82 patients (27%) died. Multivariable analysis revealed 4 independent predictors of mortality after ICD replacement: age/year (hazard ratio [HR]: 1.05, 95% confidence interval [CI]: 1.03-1.08, P = 0.01), worsening heart failure by 1 class (HR: 1.53, 95% CI: 1.15-2.03, P = 0.003), presence of left bundle branch block (HR: 1.98, 95% CI: 1.22-3.23, P = 0.006), and ICD therapy prior to replacement (HR: 2.22, 95% CI: 1.37-3.58, P = 0.001). Incorporated into a dichotomous score, they strongly correlated with mortality at 5 years after replacement (5% with 0 parameters, 15% with 1 parameter, and 30%-55% with >2 parameters).

CONCLUSIONS

Focused reassessment of selected patient characteristics at the time of ICD replacement correlates with subsequent mortality and can impact decision making at this point in time.

Outcomes After Implantable Cardioverter-Defibrillator Generator Replacement for Primary Prevention of Sudden Cardiac Death

BACKGROUND

The effectiveness of implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden death in patients with an ejection fraction (EF) ≤ 35% and clinical heart failure is well established. However, outcomes after replacement of the ICD generator in patients with recovery of EF to >35% and no previous therapies are not well characterized.

METHODS AND RESULTS

Between 2001 and 2011, generator replacement was performed at 2 tertiary medical centers in 253 patients (mean age, 68.3 ± 12.7 years; 82% men) who had previously undergone ICD placement for primary prevention but subsequently never received appropriate ICD therapy. EF had recovered to > 35% in 72 of 253 (28%) patients at generator replacement. During median (quartiles) follow-up of 3.3 (1.8-5.3) years after generator replacement, 68 of 253 (27%) experienced appropriate ICD therapy. Patients with EF ≤ 35% were more likely to experience ICD therapy compared with those with EF > 35% (12% versus 5% per year; hazard ratio, 3.57; P = 0.001). On multivariable analysis, low EF predicted appropriate ICD therapy after generator replacement (hazard ratio, 1.96 [1.35-2.87] per 10% decrement; P = 0.001). Death occurred in 25% of patients 5 years after generator replacement. Mortality was similar in patients with EF ≤ 35% and > 35% (7% versus 5% per year; hazard ratio, 1.10; P = 0.68). Atrial fibrillation (3.24 [1.63-6.43]; P < 0.001) and higher blood urea nitrogen (1.28 [1.14-1.45] per increase of 10 mg/dL; P < 0.001) were associated with mortality.

CONCLUSIONS

Although approximately one fourth of patients with a primary prevention ICD and no previous therapy have EF >35% at the time of generator replacement, these patients continue to be at significant risk for appropriate ICD therapy (5% per year). These data may inform decisions on ICD replacement.

Generator exchange in a primary prevention cardiac resynchronziation responder: do you reimplant a defibrillator?

This case-based review discusses the benefits of cardiac resynchronization therapy (CRT) and whether defibrillation function is necessary in CRT responders. An evaluation of the literature and evidence to date is discussed. Recommendations based on these data, expert opinion, and recently published appropriate use criteria are given.