Incidence Of Appropriate Implantable Cardioverter-defibrillator Therapy Research Articles

Incidence and Predictors of Appropriate Implantable Cardioverter Defibrillator Therapy in Japanese Ischemic Heart Disease Patients.

Although the efficacy of an implantable cardioverter defibrillator (ICD) in preventing sudden cardiac death is well established, the incidence and predictors of appropriate ICD therapy in Japanese ischemic heart disease (IHD) patients remain unclear. We retrospectively studied Japanese 141 IHD patients undergoing transvenous ICD or cardiac resynchronization therapy with a defibrillator (CRT-D) implantation for primary or secondary prevention at Hirosaki University Hospital. Over a mean (±SD) follow-up period of 5.5±2.8 years, the incidence of appropriate ICD therapy was similar in the primary and secondary prevention groups, although it was relatively more frequent in the first 2 years in the secondary prevention group. Four patients died due to sustained ventricular tachycardia (VT) or ventricular fibrillation (VF), mainly due to post-shock pulseless electrical activity. Once patients had received their first appropriate ICD therapy, 49.2% received second appropriate ICD therapy within 6 months. Cox proportional hazard analysis revealed that sustained VT as an index life-threatening ventricular tachyarrhythmia before ICD/CRT-D implantation was an independent predictor of appropriate ICD therapy, but VF was not. The incidence of appropriate ICD therapy was comparable in primary and secondary prevention among Japanese IHD patients. We need to recognize the high-risk period for second appropriate ICD therapy after the first therapy and sustained VT as index life-threatening ventricular tachyarrhythmia as a risk factor for appropriate ICD therapy.

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion.

Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation. The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151). Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Comparing adolescent- and adult-onset unexplained cardiac arrest: Results from the Dutch Idiopathic VF Registry

BackgroundCurrent cohorts of patients with idiopathic ventricular fibrillation (IVF) primarily include adult-onset patients. Underlying causes of sudden cardiac arrest vary with age; therefore, underlying causes and disease course may differ for adolescent-onset vs adult-onset patients. ObjectiveThe purpose of this study was to compare adolescent-onset with adult-onset patients having an initially unexplained cause of VF. MethodsThe study included 39 patients with an index event aged ≤19 years (adolescent-onset) and 417 adult-onset patients from the Dutch Idiopathic VF Registry. Data on event circumstances, clinical characteristics, change in diagnosis, and arrhythmia recurrences were collected and compared between the 2 groups. ResultsIn total, 42 patients received an underlying diagnosis during follow-up (median 7 [2–12] years), with similar yields (15% adolescent-onset vs 9% adult-onset; P = .16). Among the remaining unexplained patients, adolescent-onset patients (n = 33) had their index event at a median age of 17 [16–18] years, and 72% were male. The youngest patient was aged 13 years. In comparison with adults (n = 381), adolescent-onset patients more often had their index event during exercise (P <.01). Adolescent-onset patients experienced more appropriate implantable cardioverter-defibrillator (ICD) therapy during follow-up compared with adults (44% vs 26%; P = .03). Inappropriate ICD therapy (26% vs 17%; P = .19), ICD complications (19% vs 14%; P = .41), and deaths (3% vs 4%; P = 1) did not significantly differ between adolescent-onset and adult-onset patients. ConclusionIVF may occur during adolescence. Adolescent-onset patients more often present during exercise compared with adults. Furthermore, they are more vulnerable to ventricular arrhythmias as reflected by a higher incidence of appropriate ICD therapy.

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

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Incidence of Ventricular Arrhythmias and 1-Year Predictors of Mortality in Patients Treated With Implantable Cardioverter-Defibrillator Undergoing Generator Replacement.

BackgroundWhen implantable cardioverter defibrillator (ICD) battery is depleted most patients undergo generator replacement (GR) even in the absence of persistent ICD indication. The aim of this study was to assess the incidence of ventricular arrhythmias and the overall prognosis of patients with and without persistent ICD indication undergoing GR. Predictors of 1‐year mortality were also analyzed.Methods and ResultsPatients with structural heart disease implanted with primary prevention ICD undergoing GR were included. Patients were stratified based on the presence/absence of persistent ICD indication (left ventricular ejection fraction ≤35% at the time of GR and/or history of appropriate ICD therapies during the first generator's life). The study included 371 patients (82% male, 40% with ischemic heart disease). One third of patients (n=121) no longer met ICD indication at the time of GR. During a median follow‐up of 34 months after GR patients without persistent ICD indication showed a significantly lower incidence of appropriate ICD shocks (1.9% versus 16.2%, P<0.001) and ICD therapies. 1‐year mortality was also significantly lower in patients without persistent ICD indication (1% versus 8.3%, P=0.009). At multivariable analysis permanent atrial fibrillation, chronic advanced renal impairment, age >80, and persistent ICD indication were found to be significant predictors of 1‐year mortality.ConclusionsPatients without persistent ICD indication at the time of GR show a low incidence of appropriate ICD therapies after GR. Persistent ICD indication, atrial fibrillation, advanced chronic renal disease, and age >80 are significant predictors of 1‐year mortality. Our findings enlighten the need of performing a comprehensive clinical reevaluation of ICD patients at the time of GR.

Comparison of 2-year outcomes between primary and secondary prophylactic use of defibrillators in patients with coronary artery disease: A prospective propensity score-matched analysis from the Nippon Storm Study.

BackgroundThe Nippon Storm Study was a prospective observational study designed to gather clinical data on implantable cardioverter-defibrillator (ICD) therapy in Japanese patients.ObjectiveThe purpose of this subanalysis was to compare the incidence of ICD therapy in patients with left ventricular dysfunction owing to coronary artery disease (CAD) for primary and secondary prophylaxis of sudden cardiac death.MethodsWe analyzed data of 493 patients with CAD and ICDs (men, 87%; age, 68 ± 10 years; left ventricular ejection fraction, 36% ± 13%; primary prophylaxis, 36%). All patients were followed up for at least 2 years. Propensity score matching was used to select patient subgroups for comparison: 133 patients with ICD for primary prophylaxis and 133 with ICD for secondary indications.ResultsThere were no significant differences between primary and secondary prophylaxis groups with respect to the incidence of appropriate ICD therapy within 2 years (0.153 vs 0.239; hazard ratio, 1.565 [95% confidence interval (CI), 0.898–2.727]; P = .114). Two-year electrical storm risks were 3.3% and 9.6% with HR = 3.236 (95% CI, 1.058–9.896; P = .039) in patients with primary and secondary prophylaxis, respectively.ConclusionThe incidence of ICD therapy received by patients with CAD for primary and secondary prophylaxis was not significantly different based on our propensity score–matched analysis. However, secondary-prophylaxis ICD therapy seems to be associated with a significantly higher risk for electrical storm than primary-prophylaxis ICD therapy.

Comparison of second appropriate defibrillator therapy occurrence in patients implanted for primary prevention and secondary prevention - Sub-analysis of the Nippon Storm Study.

BackgroundPatients with implantable cardioverter defibrillator (ICD) use for primary prevention (primary prevention patients) of sudden cardiac death have lower incidence of appropriate ICD therapy (app-Tx) compared with those with ICD use for secondary prevention (secondary prevention patients). However, detail analysis of a second app-Tx after a first app-Tx is still lacking.ObjectiveThis study aimed to compare the incidence of a second app-Tx in primary vs secondary prevention patients.MethodsWe conducted sub-analysis of the Nippon Storm Study, which was a prospective, observational study involving 985 patients with structural heart disease (left ventricular ejection fraction ≤ 50%). Of these, we selected 251 patients (62 ± 14 years old, 82% men) who experienced at least one appropriate ICD therapy, and compared occurrence of a second app-Tx between primary (n = 116) and secondary (n = 135) prevention patients.ResultsThere was no significant difference in the incidence of a second app-Tx between primary and secondary prevention patients (the cumulative incidence for a second app-Tx was 59% at 1 year and 79% at 3 years in primary prevention patients vs the cumulative incidence for the second app-Tx was 59% at 1 year and 75% at 3 years in secondary prevention patients).Additionally, we evaluated the incidence of a second app-Tx according to basal structural disease (ischemic and non-ischemic cardiomyopathy) and found no significant difference between primary and secondary prevention patients.ConclusionOnce app-Tx occurs, primary prevention patients acquire the high risk of subsequent ventricular arrhythmias because there is a comparable incidence of a second app-Tx in secondary prevention patients.

Abstract 16519: Meta-analysis of Outcome After Implantable Cardioverter Defibrillator Therapy in Patients With Cardiac Amyloidosis

Introduction: Cardiac amyloidosis is associated with high risk for sudden cardiac death. However, the potential benefit of implantable cardioverter defibrillator (ICD) implantation in CA is unknown due to limited available data regarding outcomes following ICD implantation in this patient population. We sought to perform a meta-analysis of trials that evaluated the outcomes of ICD implantation in CA. Methods: We performed a systematic literature review in PubMed, SCOPUS, and Cochrane to identify all studies that evaluated ICD therapy in CA until May 2020. Outcomes analyzed were all-cause mortality and appropriate ICD therapy rates. A random effects model was used to calculate percentages and 95% confidence intervals (CI) of outcomes. Results: Of the screened articles, 5 observational studies were included for analysis. A total of 151 patients were analyzed. Mean age of population was 61.6 +/- 0.7 years and 79.2% were male. The all-cause mortality rate was 33% (95% CI:16 to 51%) and the incidence of appropriate ICD therapy was 23% (95% CI:16 to 30%) over a mean follow up period of 16 months (Figure). In trials that evaluated ICD therapy in non-ischemic cardiomyopathy such as DANISH, DEFINITE and SCD-HeFT trials mortality rates in the ICD arm were 21.6 % over 67.6 months, 9.4% over 29 months and 16.7% over 45.5 months, respectively. The incidence of appropriate therapy in DANISH, DEFINITE and SCD-HeFT trials were 28.9%, 19.8 % and 21% respectively. Conclusions: CA patients with ICD have equivalent appropriate therapy with disproportionately higher mortality over a shorter follow up compared to randomized trials of primary prevention ICD placement in NICMP. The benefit of ICD placement for mortality reduction in CA remains unclear and further large-scale studies are required to address this issue.

Preventive versus deferred catheter ablation of myocardial infarct-associated ventricular tachycardia: A meta-analysis.

BackgroundThe optimal timing of catheter ablation for the treatment of ventricular tachycardia (VT) in patients with ischemic cardiomyopathy remains unclear. Studies examining the impact of early preventive ablation of VT on rates of implantable cardioverter-defibrillator (ICD) therapies and mortality have been limited by small sample size.ObjectivesTo conduct a meta-analysis of randomized controlled trials (RCTs) comparing initial catheter ablation and ICD implantation (preventive ablation arm) vs ICD implantation alone (deferred ablation arm) in patients with ischemic cardiomyopathy and VT.MethodsThe primary endpoint was the incidence of appropriate ICD therapy during follow-up. Secondary endpoints included appropriate ICD shock, VT storm, procedural complications, and mortality. Sensitivity analysis, meta-regression, and evaluation of bias were performed.ResultsFour RCTs (n = 505) fulfilled inclusion criteria. During follow-up (mean >22 months for all RCTs), preventive ablation was associated with a significant reduction in ICD therapies (odds ratio [95% confidence interval]: 0.53 [0.36–0.78]). The occurrence of ICD shocks and VT storm were also significantly reduced in the preventive ablation group. Among patients with left ventricular ejection fraction (LVEF) >30%, preventive ablation was associated with marked reduction in ICD therapy when compared to deferred ablation (odds ratio [95% confidence interval]: 0.37 [0.19–0.72]). Overall, there was no difference in mortality between treatment groups.ConclusionsPreventive catheter ablation in patients with ischemic cardiomyopathy decreases ICD therapies, ICD shocks, and VT storm without increasing complications, particularly in patients with LVEF >30%. However, early preventive ablation is not associated with any benefit in mortality.

Primary prevention implantable cardioverter-defibrillators in hypertrophic cardiomyopathy—Are there predictors of appropriate therapy?

Identifying patients with hypertrophic cardiomyopathy (HCM) who warrant a primary prevention implantable cardioverter-defibrillator (ICD) is crucial. ICDs are effective in terminating life-threatening arrhythmias; however, ICDs carry risks of complications. The purpose of this study was to assess the incidence and predictors of appropriate ICD therapies, inappropriate shocks, and device-related complications in patients with HCM and primary prevention ICDs. All patients with HCM who underwent primary prevention ICD implantation at Toronto General Hospital between September 2000 and December 2017 were identified. Therapies (shocks or antitachycardia pacing) for ventricular tachycardia >180 beats/min or ventricular fibrillation were considered appropriate. Three hundred two patients were followed for a mean 6.1 ± 4.3 years (1801 patient-years of follow-up). Thirty-eight patients (12.6%) received at least 1 appropriate ICD therapy (2.3%/y); the 5-year cumulative probability of receiving appropriate ICD therapy was 9.6%. None of the conventional risk factors nor the European Society of Cardiology risk score was associated with appropriate ICD therapy. In multivariable analysis, age < 40 years at implantation and atrial fibrillation were independent predictors of appropriate ICD therapy. In a subgroup of patients who had undergone cardiac magnetic resonance imaging before ICD implantation, severe late gadolinium enhancement was the strongest predictor of appropriate ICD therapies. ICD-related complications or inappropriate shocks occurred in 87 patients (28.8%), with an inappropriate shock rate of 2.1%/y; the 5-year cumulative probability was 10.7%. The incidence of appropriate ICD therapies in patients with HCM and primary prevention ICDs is lower than previously reported; a high proportion of patients suffer from an ICD-related complication. Traditional risk factors have low predictive utility. Severe late gadolinium enhancement, atrial fibrillation, and young age are important predictors of ventricular tachyarrhythmias in HCM.

Predicting therapies in Japanese hypertrophic cardiomyopathy patients with an implantable cardioverter-defibrillator using the 2014 European Society of Cardiology guidelines.

Previous studies have shown that the sudden cardiac death (SCD) prediction model proposed by the 2014 European Society of Cardiology (ESC) guideline (5-Year Risk-SCD) was validated in European patients with hypertrophic cardiomyopathy (HCM). However, there are limited data on Asian patients with HCM. We assessed the validity of the estimated 5-Year Risk-SCD in Japanese HCM patients with an implantable cardioverter-defibrillator (ICD) using the2014 ESC guidelines. We retrospectively examined data of 492 consecutive Japanese patients with an ICD. Sixty-two Japanese HCM patients with an ICD were enrolled in this study, and 50 patients (81%) were followed up for ≥ 5years. We analyzed the characteristics and outcomes of these 50 patients. We investigated the incidence of appropriate ICD therapy as categorized by the ESC guideline and compared the 5-Year Risk-SCD with the 5-year rate of appropriate shock therapies. Based on the 2012 Japanese Circulation Society guideline and the 2011guidelines of the American Heart Association and American College of Cardiology Foundation, 10 and 40 patients met classes I and IIa of the ICD recommendation, respectively. However, only 18 (36%) patients were classified into class I or IIa of the ESC guideline. Among 50 patients followed up for ≥ 5years after ICD implantation, the incidences of appropriate ICD therapies for classes I, IIa, IIb, and III indications based on the 2014 ESC guideline were 50%, 38%, 17%, and 0%, respectively. Risk stratification for SCD using 5-Year Risk-SCD is valid in Japanese HCM patients with an ICD, and the 2014 ESC guideline might be useful for the indication of ICD implantation in Japan.

Revascularization of coronary chronic total occlusions in an infarct‐related artery and recurrence of ventricular arrhythmias among patients with secondary prevention implantable cardioverter defibrillator

To evaluate whether the revascularization of a coronary chronic total occlusion in an infarct-related artery (IRACTO) may be associated with lower recurrence of ventricular arrhythmias (VA) among patients with a secondary prevention implantable cardioverter defibrillator (ICD). IRACTO is increasingly recognized as an independent predictor of VA. It is unknown whether IRACTO revascularization can reduce the burden of VA. Multicenter observational cohort study that included consecutive patients with prior myocardial infarction and secondary prevention ICD. The primary endpoint was any appropriate ICD therapy. Among the 460 patients included, 269 (58%) had at least one IRACTO at the coronary angiogram performed before ICD implantation; of these, 20 (7%) had their IRACTO successfully revascularized (IRACTO-R) afterwards. During a median follow-up of 48 months, 229 patients (49%) had at least one appropriate ICD therapy. Patients with IRACTO not revascularized (IRACTO-NR) had the highest incidence of ICD therapies (65%) while patients with IRACTO-R had the lowest (10%, p < .001). In the entire cohort, IRACTO-NR was an independent predictor of appropriate ICD therapies (HR 2.85, p < .001) and appropriate ICD shocks (HR 2.94, p < .001). Among patients with IRACTO at baseline, IRACTO-R was independently associated with a marked reduction of appropriate ICD therapies (HR 0.12, p = .002) and appropriate ICD shocks (HR 0.21, p = .03). In patients with prior myocardial infarction and secondary prevention ICD, IRACTO revascularization was independently associated with a markedly lower incidence of appropriate ICD therapies and shocks. These results should be corroborated by larger prospective studies.

Clinical significance of precedent asymptomatic non-sustained ventricular tachycardias on subsequent ICD interventions and heart failure hospitalization in primary prevention ICD patients

BackgroundThe prognostic implications of non-sustained ventricular tachycardia (NSVT) and their significance as therapeutic targets in patients without prior sustained ventricular arrhythmias remain undetermined. The aim of this study was to investigate the prognostic significance of asymptomatic NSVT in patients who had primary prevention implantable cardioverter-defibrillator (ICD) implantation due to ischemic or non-ischemic cardiomyopathy (ICM, NICM).MethodsWe enrolled 157 consecutive primary prevention ICD patients without previous appropriate ICD therapy (AIT). Patients were allocated to two groups depending on the presence or absence of NSVT in a 6-month period prior to enrollment. The incidence of AIT and unplanned hospitalization due to decompensated heart failure (HF) were assessed during follow-up.ResultsIn 51 patients (32%), precedent NSVT was documented. During a median follow-up of 1011 days, AIT occurred in 36 patients (23%) and unplanned HF hospitalization was observed in 32 patients (20%). In precedent NSVT patients, the incidence of AIT and unplanned HF hospitalization was significantly higher as compared to patients without precedent NSVT (AIT: 29/51 [57%] vs. 7/106 [7%], P < 0.001, log-rank; HF hospitalization: 16/51 [31%] vs. 16/106 [15%], P = 0.043, log-rank). Cox-regression demonstrated that precedent NSVT independently predicted AIT (P < 0.0001). In subgroup analyses, precedent NSVT predicted AIT in both ICM and NICM (P < 0.0001, P = 0.020), but predicted HF hospitalization only in patients with ICM (P = 0.0030).ConclusionsPrecedent non-sustained VT in patients with primary prevention ICDs is associated with subsequent appropriate ICD therapies, and is an independent predictor of unplanned heart failure hospitalizations in patients with ischemic cardiomyopathy.

Primary prevention of sudden cardiac death in patients with tetralogy of Fallot with implantable cardioverter defibrillator: Insights from the DAI-T4F study

Ventricular arrhythmias and sudden death are feared late complications in patients with tetralogy of Fallot. Selection of candidates for primary prevention implantable cardioverter defibrillator (ICD) remains challenging. To identify patients with tetralogy of Fallot at high-risk of sudden cardiac death in primary prevention. The DAI-T4F study is an ongoing national French registry including all patients with tetralogy of Fallot and ICD ( NCT03837574 ). Information have been collected prospectively since 2010. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. Among 134 patients enrolled, 47 (35.1%) underwent ICD implantation for primary prevention (median age 49.1 years, 76.6% males). At baseline, 20 (42.6%) patients had NSVT, 17 (36.2%) had altered LVEF ≤ 35%, 16 (34.0%) had positive programmed ventricular stimulation, and 16 (34.0%) had QRS duration ≥ 180ms. During a median (IQR) follow-up duration of 5.3 (2.1–8.0) years, 14 (29.8%) patients had at least one appropriate ICD therapy. The annual incidence of appropriate ICD therapies were 2.8%, 4.6%, 6.3%, and 8.6% in patients with none, one, two, or ≥ three of these factors ( P for trend = 0.145). None of predictors, considered isolated, was significantly associated with ICD appropriate therapies. Patients with non-sustained ventricular tachycardia (NSVT) and positive programmed ventricular stimulation had a significant increased risk of ICD appropriate therapies (HR = 3.8, 95% CI: 1.1–14.3, P = 0.035), as well as patients with NSVT and QRSd ≥ 180 ms (HR = 7.2, 95% CI: 1.6–32.7, P = 0.003). No patient with severe altered LVEF without other risk factor had appropriate ICD therapy. Our data illustrate that specific risk stratification and primary prevention for sudden cardiac death in patients with tetralogy of Fallot may be improved. The value of a severely altered LVEF appears low in the absence of other risk factors.

Electrocardiographic predictors of appropriate implantable cardioverter defibrillator therapies in patients with tetralogy of Fallot

The electrocardiogram (ECG) is widely available and may contribute to a better risk stratification for sudden cardiac death in tetralogy of Fallot. To identify ECG predictors of appropriate therapies in patients with tetralogy of Fallot and implantable cardioverter defibrillator (ICD). The DAI-T4F study is an ongoing national French registry including all patients with tetralogy of Fallot and ICD ( NCT03837574 ). Information have been collected prospectively since 2010. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. A total of 134 patients (median age 41.7 years, 70.7% males) were enrolled. During a median (IQR) follow-up of 6.1 (2.7–10.2) years, 59 (44.0%) patients received at least one appropriate ICD therapy, giving annual incidence of 5.5% and 7.1% in primary and secondary prevention, respectively ( P = 0.058). Overall, QRSd ≥ 180ms ( P = 0.073), QRS fragmentation ( P = 0.052), and QRS vector magnitude (vm, P = 0.327) were not significantly associated with appropriate ICD therapies, whereas the association of QRSd ≥ 180ms and QRS fragmentation (HR = 1.9, 95% CI: 1.1–3.4, P = 0.036) were associated with an increased risk of appropriates ICD therapies. In patients with ICD for primary prevention (47 patients, 35.1%), while non-sustained ventricular tachycardia (NSVT) considered isolated was not associated with events during follow-up ( P = 0.069), combinations with QRSd ≥ 180 ms (HR = 7.2, 95% CI: 1.6–32.7, P = 0.011), QRS fragmentation (HR = 3.8, 95% CI: 1.2–12.4, P = 0.025), or decreased QRS vm (HR = 3.6, 95% CI: 1.1–12.1, P = 0.042) were all associated with a higher incidence of appropriate ICD therapies. Our findings highlight that cumulative risk score derived from ECG may contribute to improve risk stratification in patients with tetralogy of Fallot, in particular QRS fragmentation and QRS vm in association with QRS duration and other traditional risk factors.

P989Incidence of appropriate implantable cardioverter defibrillator therapy and sudden cardiac death in cardiac sarcoidosis - a systematic review and meta-analysis

Abstract Background Implantation of implantable cardioverter defibrillator (ICD) is a Class IIb indication in patients with Cardiac Sarcoid and with LVEF 36%-49% despite immunosuppression and optimal heart failure therapy. Purpose This systematic review and meta-analysis aimed to provide an estimate on the incidence of ventricular arrhythmias and risk of sudden cardiac death (SCD) in patients with CS. Methods The terms “Cardiac Sarcoidosis*” AND “Implantable Cardioverter Defibrillator” AND “Sudden Cardiac Death” were searched on PubMed, EMBASE, and Scopus on 21st of September 2018 yielding 759 articles. After exclusions, 12 studies met inclusion criteria. Results The 12 studies consisted of 612 patients with CS of which 534 had ICD implanted for primary or secondary prevention. Assuming appropriate device therapy as a surrogate for SCD, the annual incidence of appropriate ICD therapies and SCD combined was 6.3% (95% CI; 3.5%-9.1%) in primary prevention cohorts, 11.6% (95% CI; 7.8%-15.3%) in secondary prevention cohorts, and 8.7% (95% CI; 6.0%-11.5%) in both cohorts. The mean left ventricular ejection fraction (LVEF) was pooled as 59±7 (n=155) in primary prevention cohorts and 48±15 (n=48) in secondary prevention cohorts. However, the LVEF was 35±13 (n=28) in those with appropriate ICD therapy, and 49±16 (n=47) in those with ICDs without therapy. Incidence of SCD in Combined Cohorts Conclusion The incidence of ventricular arrhythmias and SCD is high not only secondary but also in primary prevention cohorts of CS. This data supports the role of implanting ICDs for primary prevention in patients with CS with mild to moderate reduction in LVEF. Acknowledgement/Funding None

5204Primary prevention of sudden cardiac death in patients with tetralogy of Fallot with implantable cardioverter defibrillator: insights from the DAI-T4F study

Abstract Background Ventricular arrhythmias and sudden death are feared late complications in patients with tetralogy of Fallot. Selection of candidates for primary prevention implantable cardioverter defibrillator (ICD) remains challenging in this population. Non-sustained ventricular tachycardia (NSVT), altered left ventricular ejection fraction (LVEF), positive programmed ventricular stimulation, and enlarged QRS are currently used for risk stratification. Purpose To identify high-risk patients with tetralogy of Fallot in the setting of primary prevention of sudden cardiac death. Methods The DAI-T4F study is a large ongoing national French registry including all patients with tetralogy of Fallot and ICD (NCT03837574). Information have been collected prospectively since 2010 with annual update. Baseline patient characteristics and clinical events during the follow-up were analyzed with central adjudication. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. Results Among 134 patients enrolled, 47 (35.1%) underwent ICD implantation for primary prevention (median age 49.1 years, 76.6% males). At baseline, 20 (42.6%) patients had NSVT, 17 (36.2%) had severe altered LVEF ≤35%, 16 (34.0%) had positive programmed ventricular stimulation, and 16 (34.0%) had QRS duration ≥180ms. Overall, 20 (42.6%), 15 (31.9%), and 6 (12.8%) patients had respectively one, two, or ≥ three of these risk factors. Six (12.8%) patients were implanted for other indications. During a median (IQR) follow-up duration of 5.3 (2.1–8.0) years, 14 (29.8%) patients had at least one appropriate ICD therapy. The annual incidence of appropriate ICD therapies were 2.8%, 4.6%, 6.3%, and 8.6% in patients with none, one, two, or ≥ three of these factors (p for trend = 0.145). None of predictors, considered isolated, was significantly associated with ICD appropriate therapies. Patients with non-sustained ventricular tachycardia (NSVT) and positive programmed ventricular stimulation had a significant increased risk of ICD appropriate therapies (HR=3.8, 95% CI: 1.1–14.3, p=0.035), as well as patients with NSVT and QRSd ≥180 ms (HR=7.2, 95% CI: 1.6–32.7, p=0.003). No patient with severe altered LVEF without other risk factor had appropriate ICD therapy. Patients with congestive heart failure and/or altered LVEF had a higher risk of non-sudden death or cardiac transplantation (HR=14.4, 95% CI: 1.8–112.7, p&lt;0.001). Seventeen (36.2%) patients experienced at least one ICD-related complication. Conclusions Our data illustrate that specific risk stratification and primary prevention for sudden cardiac death in patients with tetralogy of Fallot may be improved. The value of a severely altered LVEF appears low in the absence of other risk factors, and combination of different predictors is essential. The high rate of complications as well as consideration of competing risk situation have to be integrated in the benefit-risk equation.

5205Electrocardiographic predictors of appropriate implantable cardioverter defibrillator therapies in patients with tetralogy of Fallot

Abstract Background The electrocardiogram (ECG) is widely available and may contribute to a better risk stratification for sudden cardiac death in patients with tetralogy of Fallot. QRS duration has been consistently associated with outcomes, with a lack of specificity for sudden mortality and a relatively low predictive value. New markers such as QRS fragmentation and vectocardiographic parameters have been recently suggested. Purpose To identify ECG predictors of appropriate therapies in patients with tetralogy of Fallot and implantable cardioverter defibrillator (ICD). Methods The DAI-T4F study is a large ongoing national French registry including all patients with tetralogy of Fallot and ICD (NCT03837574). Information have been collected prospectively since 2010 with annual update. Baseline patient characteristics and clinical events during the follow-up were analyzed with central adjudication. Cox proportional hazard models were used to identify factors associated with appropriate ICD therapies. Results A total of 134 patients (median age 41.7 years, 70.7% males) were enrolled. During a median (IQR) follow-up of 6.1 (2.7–10.2) years, 59 (44.0%) patients received at least one appropriate ICD therapy, giving annual incidence of 5.5% and 7.1% in primary and secondary prevention, respectively (p=0.058). Overall, QRSd ≥180ms (p=0.073), QRS fragmentation (p=0.052), and QRS vector magnitude (vm, p=0.327) were not significantly associated with appropriate ICD therapies, whereas QRS fragmentation in right leads (HR=1.7, 95% CI: 1.1–2.9, p=0.039) and the association of QRSd ≥180ms and overall QRS fragmentation (HR=1.9, 95% CI: 1.1–3.4, p=0.036) were associated with an increased risk of appropriates ICD therapies. In patients with ICD for primary prevention (47 patients, 35.1%), 53.8% had QRS fragmentation, 48.6% had decreased QRS vm, and 41.0% had QRSd ≥180ms. In this group, while non-sustained ventricular tachycardia (NSVT) considered isolated was not associated with ventricular events during follow-up (p=0.069), respective combinations with QRSd ≥180 ms (HR=7.2, 95% CI: 1.6–32.7, p=0.011), QRS fragmentation (HR=3.8, 95% CI: 1.2–12.4, p=0.025), or decreased QRS vm (HR=3.6, 95% CI: 1.1–12.1, p=0.042) were all associated with a higher incidence of appropriate ICD therapies. Positive predictive value and negative predictive value were 0.33 and 0.85, 0.58 and 0.74, and 0.36 and 0.84 in patients with NSVT and QRS ≥180ms, NSVT and QRS fragmentation, and NSVT and decreased QRS vm, respectively. Conclusions Our findings highlight that cumulative risk score derived from ECG may contribute to improve risk stratification in patients with tetralogy of Fallot, in particular QRS fragmentation and QRS vm in association with QRS duration and other traditional risk factors.

Arrhythmic burden among asymptomatic patients with ischemic cardiomyopathy and an implantable cardioverter-defibrillator

The clinical benefit of primary prevention implantable cardioverter-defibrillator (ICD) therapy in asymptomatic patients (New York Heart Association [NYHA] functional class I) with ischemic cardiomyopathy and left ventricular dysfunction is continually disputed. The purpose of this study was to evaluate the incidence of ventricular arrhythmias, mortality rates, and appropriate device therapies by NYHA class in a prospective national ICD registry. The study comprised 1670 consecutive patients with ischemic cardiomyopathy who were implanted with a primary prevention ICD and enrolled in the prospective national Israeli ICD Registry from 2010. The risk for clinical and arrhythmic events was assessed by NYHA class. Asymptomatic patients (NYHA I) composed 19% of the study cohort. Comparison according to NYHA class showed that the highest mortality rate was in the NYHA III-IV group vs NYHA I and NYHA II (10.5% vs 5.4% and 5.8%, respectively; log rank P= .003). Conversely, cumulative incidence of appropriate ICD therapies, corrected for death as a competing risk, were higher among patients with NYHA I (11% vs 7%; P = .021). In a multivariate model, NYHA I vs ≥II remained independently associated with a significant 2-fold risk for appropriate ICD therapy (hazard ratio 2.03; 95% confidence interval 1.28-3.24). Our findings indicate that patients with ischemic cardiomyopathy without heart failure symptoms have a higher risk of appropriate ICD therapy compared with symptomatic patients after adjustment for the competing risk of death, suggesting possible incremental benefit of primary ICD implantation in this population.

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

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. 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. 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.