Prophylactic ICD Implantation Research Articles

Periodic Repolarization Dynamics (PRD) identifies patients who profit from ICD implantation, A meta-analysis of the predictive value of PRD

Abstract Background Periodic repolarization dynamics (PRD) is an electrocardiographic marker that quantifies sympathetic-activity associated instabilities of cardiac repolarization. PRD is a strong predictor of mortality in patients with ischemic (ICM) and non-ischemic cardiomyopathy (NICM) and has been proposed to identify patients who benefit from prophylactic ICD implantation. Purpose To conduct a systematic review and meta-analysis concerning the prognostic value of PRD for predicting all-cause mortality in relation to prophylactic ICD-implantation. Methods This meta-analysis follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. A total of 25 articles were screened and 7 randomized and non-randomized controlled trials identified. Finally, a total of 5 could be included in the analysis (Fig.1). Patients were stratified into patients with or without prophylactic ICD-implantation (Fig.2). The prognostic value of PRD for predicting all-cause mortality was extracted from published data as hazard ratio (HR) per 1 deg2 increase in PRD. We used inverse-variance-weighted average meta-analysis to calculate fixed and random effect models to estimate the overall predictive value of PRD in both groups. The interaction between PRD and prophylactic ICD-implantation for predicting mortality was calculated using meta-regression analysis. All analyses were performed using CRAN R v. 4.1.2 and the meta-package v 5.2.0. Results We included 4,338 patients in this meta-analysis, of whom 3,167 (73%) suffered from ICM and 1,171 (27%) from NICM. 1,906 (44%) patients were treated with an ICD. During an estimated mean follow-up time of 3.2 years, 604 (14%) patients died. Fig. 2 (left) shows patients without ICD treatment (N = 2,432, 56%). In these patients, a 1 deg2 increase in PRD was significantly associated with an overall 8% increase in mortality (fixed effect HR 1.08; 95% CI 1.06-1.10; p< 0.001, random effect HR 1.08; 95% CI 1.06-1.11; p < 0.001). Fig. 2 (right) displays the prognostic value of PRD in patients treated by ICD (N = 1,906). In these patients, a 1 deg2 increase in PRD was significantly associated with an overall 3% increase in mortality (fixed-effect HR 1.03; 95% CI 1.01-1.05; p< 0.001, random-effect HR 1.03; 95% CI 1.00-1.06; p < 0.001). An increase in PRD was not significantly associated with an increase in mortality in patients from the EU-CERT-ICD and DANISH trial. There was a significant interaction between PRD and prophylactic ICD-implantation for predicting all-cause mortality (p = 0.008). Conclusion In patients with ICM and NICM, PRD is a strong predictor of all-cause mortality in patients with and without prophylactic ICD. The significant interaction between PRD and prophylactic ICD-implantation most probably implies a reduction in the risk identified by PRD through ICD implantation. Consequently, PRD could prove a useful tool for identifying patients that might benefit from ICD treatment.Figure 1Figure 2

Improving sudden cardiac death risk stratification in hypertrophic cardiomyopathy using established clinical variables and genetic information

Background and aimsThe cardiac societies of Europe and the United States have established different risk models for preventing sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). The aim of this study is to validate current SCD risk prediction methods in a German HCM cohort and to improve them by the addition of genotype information.MethodsHCM patients without prior SCD or equivalent arrhythmic events ≥ 18 years of age were enrolled in an expert cardiomyopathy center in Germany. The primary endpoint was defined as SCD/-equivalent within 5 years of baseline evaluation. 5-year SCD-risk estimates and recommendations for ICD implantations, as defined by the ESC and AHA/ACC guidelines, were analyzed. Multivariate cox proportional hazards analyses were integrated with genetic findings as additive SCD risk.Results283 patients were included and followed for in median 5.77 years (2.92; 8.85). A disease-causing variant was found in 138 (49%) patients. 14 (5%) patients reached the SCD endpoint (5-year incidence 4.9%). Kaplan–Meier survival analysis shows significantly lower overall SCD event-free survival for patients with an identified disease-causing variant (p < 0.05). The ESC HCM Risk-SCD model showed an area-under-the-curve (AUC) of 0.74 (95% CI 0.68–0.79; p < 0.0001) with a sensitivity of 0.29 (95% CI 0.08–0.58) and specificity of 0.83 (95% CI 0.78–0.88) for a risk estimate ≥ 6%/5-years. By comparison, the AHA/ACC HCM SCD risk stratification model showed an AUC of 0.70 (95% CI 0.65–0.76; p = 0.003) with a sensitivity of 0.93 (95% CI, 0.66–0.998) and specificity of 0.28 (95% CI 0.23–0.34) at the respective cut-off. The modified SCD Risk Score with genetic information yielded an AUC of 0.76 (95% CI 0.71–0.81; p < 0.0001) with a sensitivity of 0.86 (95% CI 0.57–0.98) and specificity of 0.69 (95% CI 0.63–0.74). The number-needed-to-treat (NNT) to prevent 1 SCD event by prophylactic ICD-implantation is 13 for the ESC model, 28 for AHA/ACC and 9 for the modified Genotype-model.ConclusionThis study confirms the performance of current risk models in clinical decision making. The integration of genetic findings into current SCD risk stratification methods seem feasible and can add in decision making, especially in borderline risk-groups. A subgroup of patients with high SCD risk remains unidentified by current risk scores.Graphical abstract

Incidence of ventricular tachyarrhythmias and clinical outcomes in primary prophylactic ICD patients in relation to localization of myocardial infarction

Abstract Funding Acknowledgements Type of funding sources: None. Introduction According to current guidelines, primary prophylactic ICD implantation is indicated with a class IA recommendation in patients with severely reduced EF &amp;lt; 35% and ischaemic heart disease. However, it is unclear whether there are differences in patient outcomes related to the localization of myocardial infarction. Aim of the study was to compare the incidence of ventricular tachyarrhythmias and clinical outcomes in primary prophylactic ICD-patients with ischaemic heart disease in relation to the localization of myocardial infarction. Methods A total of 448 consecutive ICD patients from a prospective single-centre ICD-registry who underwent primary prophylactic ICD implantation due to ischaemic cardiomyopathy between 1996 and 2021 were analyzed. Patients with previous anterior wall myocardial infarction (AWMI, n = 293) were compared to those with posterior wall myocardial infarction (PWMI, n = 155). Patients with both AWMI and PWMI were excluded. The median follow-up time was 6 years in both groups. Results Patients with AMWI were younger, more often female, and less often received cardiac synchronization therapy (Table 1). Patients with previous PWMI more often had ICD therapy during follow-up (Figure 1) due to the higher incidence of ventricular tachycardias (Table 1). The all-cause mortality rate was similar between both groups. Conclusion Primary prophylactic ICD patients with previous PWMI have a 10% higher incidence of ventricular tachycardias after 6-year follow-up than ICD patients with previous AMWI. This might be explained by the proximity of the inferior infarction to the mitral isthmus and should be considered when ablating VTs in patients with PWMI.

Value of programmed electrical stimulation in Brugada Syndrome: a cohort study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Prognostic value of programmed electrical stimulation (PES) in Brugada Syndrome (BrS) remains controversial. Substantial controversy exists regarding usefulness of PES in identifying BrS patients at risk of sudden cardiac death (SCD). Implantation of an implantable cardioverter-defibrillator is the only reliable form of SCD prevention in this specific population Purpose To determine if induction of sustained ventricular arrhythmia (VA) in PES is a predictor of cardiac events (CE), defined as the composite of SCD, appropriate ICD therapy for VA or unexplained syncope. Methods A retrospective analysis of 34 patients with spontaneous or pharmacologically induced type 1 Brugada pattern, submitted to electrophysiology study with PES between 2015 and 2019 in a Portuguese Center, was performed. Patients were followed for 24 months. Hospital records and monitoring data from cardiac devices were consulted. The Mann-Whitney U test was used for median comparison between groups. Binary logistic regression through the stepwise method was performed to evaluate categorical features. Results 35% (n=12) and 27% (n=9) had spontaneous type 1 and type 2 Brugada pattern in basal electrocardiography, respectively. 23% (n=8) had VA induced by PES. The mean age was 51,2±12,3 years. 71% (n=24) were male. 15% (n=5) had history of cardiac syncope, and 27% (n=9) had a family history of SCD. 9% (n=3) were carriers of a SNC5A mutation. Mean AH time and HV time were, respectively, 105±31,9, and 49±8,5ms. During the 24 months of follow-up, 9% (n=3) suffered a CE (2 unexplained syncope and 1 SCD). None of the patients who suffered CE had VA inducible at PES study. There was no statistical significance in the occurrence of cardiac events when comparing both groups (VA induced in PES vs. no induced arrhythmia) (p=0,49, OR 0,89, IC 95% 0,70;1,02). Through binary logistics, adjusted for potential confounders (gender, history of syncope, history of family SCD and identification of a genetic variant), patients with spontaneous type 1 Brugada pattern in basal electrocardiography were 2,2 times more likely to have a CE (IC 95% 0,12;40,2). Conclusion In this population, VA induced by PES was not a predictor of CE during the follow-up period, which highlights the difficulty of risk stratification in patients with BrS. New risk-stratification tools are urgently needed to select those patients at higher-risk of SCD, which are candidates for prophylactic ICD implantation.

449 HYPERTROPHIC CARDIOMYOPATHY: A CASE OF CHALLENGING ARRHYTHMIC RISK STRATIFICATION

Abstract Hypertrophic cardiomyopathy (HCM) is a common disease, mostly inherited, with a prevalence of 1:500. Cornerstone of the clinical management of HCM patients is stratifying the risk of sudden cardiac death (SCD) which is the most frightening complication despite its relatively low incidence (0,9% per year). Although mathematical risk scores, as proposed by ESC, are the most used to assess the probability of arrhythmic complications leading to SCD, they have been associated with low sensitivity, precluding some high-risk patients from prophylactic ICD implantation. Among the tools at clinicians’ disposal for risk stratification in HCM patients, the latest AHA/ACC guidelines propose an “individual risk markers strategy”, based on the presence of ≥1 clinical feature such as a family history of SCD, extreme left ventricular hypertrophy (LVH), unexplained recent syncope, NSVT, late gadolinium enhancement (LGE) at CMR, systolic dysfunction and LV apical aneurysm. We present a case that lets us reflect on arrhythmic risk stratification. P.C. is a 58 y.o. male with a history of septal hypertrophy (19 mm) and T wave inversion but without an established diagnosis of HCM. He did not have any familiar history of syncope or SCD. He came to the emergency department for epistaxis and was admitted to the cardiology unit due to the previously mentioned findings, where he underwent cardiac-CTA and CMR showing myocardial bridge of left anterior descending artery, LVH with apical aneurysm and LGE areas localized on the apex (transmural) and on the interventricular septum (subendocardial). No signs of dynamic LVOT obstruction or atrial enlargement emerged from echocardiography. During the observation, asymptomatic NSVT were recorded on continuous ECG monitoring. According to the ESC risk prediction score (3.7%) ICD was not strictly indicated but considering the CMR high-risk profile (according to the suggestions of AHA/ACC) we proposed an ICD implantation anyways. The patient refused any invasive procedure and was implanted with a loop recorder. At 12 months remote monitoring showed a single episode of self-terminated sustained polymorphic ventricular tachycardia (02:23 mm: ss) symptomatic of pre-syncope. The patient was then immediately reached and admitted for ICD implantation in secondary prevention. According to the patient's will, and the no need for bradycardia therapy, an S-ICD was implanted. Figure 1LV apical aneurysm at CMRFigure 2Remote Monitoring

The DAPA Trial in the Context of Previous Prophylactic ICD Landmark Trials.

In patients with ischaemic cardiomyopathy and severely reduced left ventricular ejection fraction (LVEF), an arrhythmogenic milieu is created by a complex interplay between myocardial scarring (assessed by cardiac MRI) and multiple other factors (ventricular ectopy, ischaemia and autonomic imbalance), favouring the occurrence of arrhythmic sudden cardiac death (SCD). Currently, a dynamic and robust model of dichotomised SCD risk assessment after primary percutaneous coronary intervention (PCI) is lacking, underlining the urgent need for further refinement of the widely accepted and guidelines-based criteria (ischaemic cardiomyopathy, LVEF ≤35%) for primary prevention. This review addresses the potential additional value of the recently published Defibrillator After Primary Angioplasty (DAPA) trial results. The DAPA trial conveys important messages and provides novel perspectives regarding left ventricular function post-primary PCI as an (early) risk marker for SCD and the impact of prophylactic ICD implantation on survival in this cohort. In the context of other previous primary prevention trials, DAPA was the first trial including only ST-elevation MI patients all treated with acute PCI.

A novel risk model for predicting potentially life-threatening arrhythmias in non-ischemic dilated cardiomyopathy (DCM-SVA risk)

BackgroundNon-ischemic dilated cardiomyopathy (DCM) can be complicated by sustained ventricular arrhythmias (SVA) and sudden cardiac death (SCD). By now, left-ventricular ejection fraction (LV-EF) is the main guideline criterion for primary prophylactic ICD implantation, potentially leading either to overtreatment or failed detection of patients at risk without severely impaired LV-EF. The aim of the European multi-center study DETECTIN-HF was to establish a clinical risk calculator for individualized risk stratification of DCM patients. Methods1393 patients (68% male, mean age 50.7 ± 14.3y) from four European countries were included. The outcome was occurrence of first potentially life-threatening ventricular arrhythmia. The model was developed using Cox proportional hazards, and internally validated using cross validation. The model included seven independent and easily accessible clinical parameters sex, history of non-sustained ventricular tachycardia, history of syncope, family history of cardiomyopathy, QRS duration, LV-EF, and history of atrial fibrillation. The model was also expanded to account for presence of LGE as the eight8h parameter for cases with available cMRI and scar information. ResultsDuring a mean follow-up period of 57.0 months, 193 (13.8%) patients experienced an arrhythmic event. The calibration slope of the developed model was 00.97 (95% CI 0.90–1.03) and the C-index was 0.72 (95% CI 0.71–0.73). Compared to current guidelines, the model was able to protect the same number of patients (5-year risk ≥8.5%) with 15% fewer ICD implantations. ConclusionsThis DCM-SVA risk model could improve decision making in primary prevention of SCD in non-ischemic DCM using easily accessible clinical information and will likely reduce overtreatment.

Management and outcomes of hypertrophic cardiomyopathy in young adults

Management of young adults with hypertrophic cardiomyopathy (HCM) is challenging. To evaluate the profile of young adults (16-25 years) with HCM included in the French prospective HCM registry. Patients were compared according to occurrence of major adverse cardiac events (MACE), comprising sudden cardiac death (SCD) events (implantable cardioverter defibrillator [ICD] discharge, SCD, sustained ventricular tachycardia), atrial fibrillation/embolic stroke, heart failure hospitalisation and unexplained syncope, at a mean follow-up of 4.4±2.2 years. At baseline, among 61 patients (20.5±3.0 years; 16 women, 26.2%), 13 (21.3%) had a prophylactic ICD, 24.6% a family history of SCD, 29.5% obstruction, 86.0% magnetic resonance imaging myocardial fibrosis, 11.8% abnormal exercise blood pressure and 52.8% a European Society of Cardiology (ESC) 5-year SCD score<4% (24.5%≥6%). At follow-up, 15 patients (24.6%; seven women; all with fibrosis) presented 17 MACE, comprising: SCD events (n=7, 41.2%; including three patients with an ICD, five with at least one SCD major classical risk factor and an ESC score≥5% and two with no risk factors and an ESC score<4%); atrial fibrillation/stroke (n=6, 35.3%); heart failure (n=1, 5.9%); syncope (n=3, 17.6%). An ICD was implanted in 11 patients (four for secondary prevention), but in only 61.5% of patients with a score≥6%. Only obstruction significantly increased MACE risk (odds ratio 3.96; P=0.035), with a non-significant trend towards a lower risk in men (OR 0.29; P=0.065). In young adults with HCM, MACE are common in the short term, especially in obstructive HCM and women, mostly arrhythmic in origin. Prophylactic ICD implantation is frequent and does not strictly follow the guidelines, while the use of European/USA guidelines is helpful but imperfect in identifying SCD risk.

Nocturnal respiratory rate predicts ICD benefit: A prospective, controlled, multicentre cohort study.

BackgroundImplantable cardioverter defibrillators (ICDs) prevent sudden cardiac death. ICD implantation decisions are currently based on reduced left ventricular ejection fraction (LVEF≤35%). However, in some patients, the non-arrhythmic death risk predominates thus diminishing ICD-therapy benefits. Based on previous observations, we tested the hypothesis that compared to the others, patients with nocturnal respiratory rate (NRR) ≥18 breaths per minute (brpm) benefit less from prophylactic ICD implantations.MethodsThis prospective cohort study was a pre-defined sub-study of EU-CERT-ICD trial conducted at 44 centers in 15 EU countries between May 12, 2014, and September 6, 2018. Patients with ischaemic or non-ischaemic cardiomyopathy were included if meeting primary prophylactic ICD implantation criteria. The primary endpoint was all-cause mortality. NRR was assessed blindly from pre-implantation 24-hour Holters. Multivariable models and propensity stratification evaluated the interaction between NRR and the ICD mortality effect. This study is registered with ClinicalTrials.gov (NCT0206419).FindingsOf the 2,247 EU-CERT-ICD patients, this sub-study included 1,971 with complete records. In 1,363 patients (61.7 (12) years; 244 women) an ICD was implanted; 608 patients (63.2 (12) years; 108 women) were treated conservatively. During a median 2.5-year follow-up, 202 (14.8%) and 95 (15.6%) patients died in the ICD and control groups, respectively. NRR statistically significantly interacted with the ICD mortality effect (p = 0.0070). While the 1,316 patients with NRR<18 brpm showed a marked ICD benefit on mortality (adjusted HR 0.529 (95% CI 0.376–0.746); p = 0.0003), no treatment effect was demonstrated in 655 patients with NRR≥18 brpm (adjusted HR 0.981 (95% CI 0.669–1.438); p = 0.9202).InterpretationIn the EU-CERT-ICD trial, patients with NRR≥18 brpm showed limited benefit from primary prophylactic ICD implantation. Those with NRR<18 brpm benefitted substantially.FundingEuropean Community's 7th Framework Programme FP7/2007-2013 (602299)

Clinical effectiveness of primary prevention implantable cardioverter-defibrillators: results of the EU-CERT-ICD controlled multicentre cohort study.

AimsThe EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter-Defibrillators (EU-CERT-ICD), a prospective investigator-initiated, controlled cohort study, was conducted in 44 centres and 15 European countries. It aimed to assess current clinical effectiveness of primary prevention ICD therapy.Methods and resultsWe recruited 2327 patients with ischaemic cardiomyopathy (ICM) or dilated cardiomyopathy (DCM) and guideline indications for prophylactic ICD implantation. Primary endpoint was all-cause mortality. Clinical characteristics, medications, resting, and 12-lead Holter electrocardiograms (ECGs) were documented at enrolment baseline. Baseline and follow-up (FU) data from 2247 patients were analysable, 1516 patients before first ICD implantation (ICD group) and 731 patients without ICD serving as controls. Multivariable models and propensity scoring for adjustment were used to compare the two groups for mortality. During mean FU of 2.4 ± 1.1 years, 342 deaths occurred (6.3%/years annualized mortality, 5.6%/years in the ICD group vs. 9.2%/years in controls), favouring ICD treatment [unadjusted hazard ratio (HR) 0.682, 95% confidence interval (CI) 0.537–0.865, P = 0.0016]. Multivariable mortality predictors included age, left ventricular ejection fraction (LVEF), New York Heart Association class <III, and chronic obstructive pulmonary disease. Adjusted mortality associated with ICD vs. control was 27% lower (HR 0.731, 95% CI 0.569–0.938, P = 0.0140). Subgroup analyses indicated no ICD benefit in diabetics (adjusted HR = 0.945, P = 0.7797, P for interaction = 0.0887) or those aged ≥75 years (adjusted HR 1.063, P = 0.8206, P for interaction = 0.0902).ConclusionIn contemporary ICM/DCM patients (LVEF ≤35%, narrow QRS), primary prophylactic ICD treatment was associated with a 27% lower mortality after adjustment. There appear to be patients with less survival advantage, such as older patients or diabetics.

Prospective evaluation of outcome of Indian patients who meet MADIT II (Multicenter Automatic Defibrillator Implantation Trial) criteria for implantable cardioverter defibrillator implantation: is it appropriate for Indian patients?

BackgroundThe MADIT II investigators had concluded that prophylactic use of an ICD improved survival in patients with prior myocardial infarction reduced left ventricular ejection fraction. Whether MADIT II criteria for ICD implantation are appropriate for Indian patients also is unclear and not studied. MethodsA total of 144 patients, Mean age 56.23 ± 10.9 years who met MADIT II criteria were prospectively followed for 20.78 + 5.9 months. ResultsDuring the follow-up period, 26 (18.1%) patients died. 18 were sudden cardiac deaths and 8 were non SCD deaths. Total mortality did not correlate with Age, NYHA class, NSVT on Holter, PVC >10/hours, QRS width, or use of statins. Multivariate logistic regression model identified the following variables associated with increase all-cause mortality: No use of beta blocker (odd ratio:13.068, p = 0.021), No past revascularization (odd ratio:11.613,p = 0.007) and Increase serum creatinine level (odd ratio: 4.066, p = 0.035). The mortality rate in the present series was comparable with that in the MADIT II conventional therapy group though patient in present study are younger, less diabetic, hypertensive, smokers and better treated with beta-blockers, ACE/ARB and statin. ConclusionIndian patients with prior MI (more than one month back) and left ventricular ejection fraction of 30% or less had a cardiac mortality similar to western population who are not treated with prophylactic ICD. Patients of Indian origin should derive a similar benefit with prophylactic implantation of ICD as per MADIT II criteria as would a western population.

Contemporary benefit-harm profile over two decades in primary prophylactic ICD-therapy.

BackgroundImplantable cardioverter defibrillator (ICD) was implemented into clinical routine more than 20 years ago. Since then, ICD therapy became standard therapy for primary and secondary prevention of sudden cardiac death in clinical practice.ObjectivesAim of the study was to evaluate the benefit‐harm profile of contemporary primary prophylactic ICD therapy.MethodsA total of 1222 consecutive patients of a prospective single‐center ICD‐registry were analyzed who underwent primary prophylactic ICD implantation between 2000 and 2017. Patients were divided into two groups according to the implantation year: 2010‐2017 (group 1, n = 579) and 2000‐2009 (group 2, n = 643).ResultsThe rate of estimated appropriate ICD therapy after 8 years was 51% in the 2000s and 42% in the 2010s (P < .001). The complication rate changed slightly from 53% to 47% (P = .005). This decline was mainly driven by the reduction of inappropriate ICD shocks (30% vs 14%, P < .001) whereas the rate of ICD shock lead malfunction and device/ lead infection remained unchanged over time. Nonischemic cardiomyopathy was an independent predictor for ICD complications without benefit of ICD therapy (HR 1.37, 95% CI 1.07‐1.77).ConclusionThe ICD therapy rate for ventricular arrhythmias in patients with primary prophylactic ICD implantation is decreasing over the last two decades. Complication rate remains high due to an unchanged rate of ICD shock malfunctions and device infections. Nonischemic cardiomyopathy is an independent predictor for ICD complications without benefit of ICD therapy in primary prophylactic ICD‐therapy.

Abstract 17194: Incremental Value of JTc Interval in Improving Risk Stratification for Life-Threatening Ventricular Arrhythmias in Patients Considered Low Risk by LVEF

Introduction: ICD implantation is recommended in patients with LVEF&lt;35%, while those with LVEF between 35 to 40% are not considered at high risk for primary prevention ICD implantation. A subset of these patients develops life threatening ventricular arrhythmias (VA) and improvement in risk stratification may help identify and implement life-saving intervention. Hypothesis: Prolonged repolarization is a marker of electrical instability and JTc interval on ECG could provide prognostic information in patients with LVEF 35-40% incremental to that from LVEF. Methods: Patients ≥18 yr with no history of VA and an ECG and echocardiogram obtained at initial encounter between 11/2011 to 12/2016 with long-term follow-up were identified. The incremental predictive ability of JTc interval on improvement in risk stratification for VA was determined by receiver operating characteristics (ROC) curve, integrated discrimination improvement (IDA) and net reclassification improvement (NRI) analysis. All tests were performed at a 5% level of significance. Results: Out of 29,700 pts that met inclusion criteria, 1,102 (3.7%) had LVEF 35-40% (mean age 70.5±14.6 yrs, 49% males, CAD 67%) and 24,894 (84%) LVEF &gt;40% (65.9±16.3 yrs , 61.8% M). Over the mean follow-up of 4.6±4.2 years, the incidence of VT/VF/cardiac arrest was 16.1% in patients with LVEF 35-40% compared to 4.1% with LVEF &gt;40%. For every 50 ms increase in JTc interval above 300 ms, the risk for arrhythmic event in LVEF 35-40% increased two-fold (Odds Ratio=1.83 (95 % CI 1.72-1.94, P=0.013). Incorporation of JTc to LVEF improved the C statistics (95% Confidence Limit) in the model with only LVEF from 0.56 (0.54-0.57) to 0.72 (0.70-0.73) for the model combining LVEF and JTc. In addition, NRI was estimated at 0.57, which was statistically significant with p values &lt;0.001 while IDI was estimated as 0.015 with p values &lt;0.001 for the model incorporating JTc to LVEF. Conclusions: In patients with LVEF 35-40% considered low risk for life threatening VA by EF, incorporating JTc interval information improved risk stratification and identified those who subsequently developed VT/VF or cardiac arrest and thus identifies a subgroup that can benefit from prophylactic ICD implantation.

P463Risk assessment for primary prophylactic ICD implantation in hypertrophic cardiomyopathy using the risk calculator: discrepancy between theory and clinical practice?

P463Risk assessment for primary prophylactic ICD implantation in hypertrophic cardiomyopathy using the risk calculator: discrepancy between theory and clinical practice?

P1746Risk stratification for patients undergoing primary prophylactic ICD implantation- the role of CMR imaging for predicting new onset ventricular arrhythmias and death

P1746Risk stratification for patients undergoing primary prophylactic ICD implantation- the role of CMR imaging for predicting new onset ventricular arrhythmias and death

LOW COMPLIANCE OF IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR USE FOR HEART FAILURE WITH REDUCED EJECTION FRACTION IN AN UNDERSERVED POPULATION

It is well established that primary prophylactic ICD (P-ICD) implantation for heart failure (HF) for patients with a sustained left ventricle ejection fraction (LVEF) ≤ 35% has a significant survival benefit. However, data regarding rates of P-ICD implantation is scant especially in underserved

PROPHYLACTIC IMPLANTABLE CARDIOVERTER DEFIBRILLATOR IN CARDIAC SARCOIDOSIS: SAVE A LIFE, COST A JOB?

Cardiac sarcoidosis (CS) is a granulomatous disease that could result in life threatening arrhythmias. Recent HRS expert consensus statement recommends prophylactic ICD implantation in patients with CS who requires a pacemaker implantation for high degree AV block. A 55-year-old Caucasian

IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS IN PATIENTS WITH SYSTEMIC RIGHT VENTRICLES

Patients with L-TGA are believed to be at an increased risk of SCD, however it is unclear what criteria justify ICD implantation. In patients with D-TGA and intra-atrial baffles, high appropriate shock rates have been observed in secondary but not primary prevention. We describe the baseline characteristics and long-term outcomes of patients with a systemic RV due to either L- or repaired D-TGA and an ICD in situ, in whom at least 2 years of follow-up data were available. Patients with univentricles or CRT therapy were excluded. Thirteen patients were included; 9 with D-TGA (all Mustard repair, 29+/-8.1yrs at implant; 89% male) and 4 with L-TGA (36+/-4.2yrs; 100% male). All received dual chambers ICDs, the majority upgraded from PPMs. Implant dates were 2000-2012, mean follow-up 8.5 yrs. Patient characteristics, procedural outcomes and follow-up events are shown in table 1. The D-TGA patients in this cohort had a worse RVEF than the L-TGA group. All patients with L-TGA had a bradycardic indication for pacing (AV block). ICD implantation was for primary prevention in all but one. This patient had a syncopal episode, associated with ventricular high rates detected on prior pacemaker and subsequent inducible VT on EPS. No patient with L-TGA had an appropriate therapy during follow-up, whilst all had ≥1 complication and two patients had ≥1 inappropriate shock. All were alive at the end of follow-up. In contrast, of the 9 patients with D-TGA, only 5 had a bradycardic indication for pacing (4 sinus node disease, 1 AV block); 7 were implanted for primary prevention. One (implanted for secondary prevention) had an appropriate shock and 6 received ≥1 inappropriate shocks. Three had died at the end of follow-up, 2 from end stage heart failure and one of complications post-cardiac transplantation. In this contemporary cohort of patients with L-TGA and an ICD in situ, long term outcome was good and no patient received an appropriate therapy, however there was a significant amount of morbidity associated with ICD implantation. Mortality in patients with D-TGA was greater, however this was not due to arrhythmic death. Low event and high complication rates were observed in D-TGA primary prevention patients, in keeping with previous data. Risk stratification in patients with systemic RV prior to prophylactic ICD implantation is essential.

Primary and secondary prophylactic ICD therapy in congenital electrical and structural cardiomyopathies

Congenital electrical and structural cardiomyopathies are rare and associated with an increased risk for syncope and sudden cardiac death in the young. Due to the young age of the patients and the limited data available, risk stratification and especially ICD therapy are challenging. In this young patient collective, ICD therapy is associated with a high complication rate, which does not justify unreserved primary prophylactic ICD implantation. The aim of this review is to elucidate risk stratification and ICD therapy of various electrical and structural cardiomyopathies.

Percutaneous Septal Ablation in Hypertrophic Obstructive Cardiomyopathy: From Experiment to Standard of Care

Hypertrophic cardiomyopathy (HCM) is one of the more common hereditary cardiac conditions. According to presence or absence of outflow obstruction at rest or with provocation, a more common (about 60–70%) obstructive type of the disease (HOCM) has to be distinguished from the less common (30–40%) nonobstructive phenotype (HNCM). Symptoms include exercise limitation due to dyspnea, angina pectoris, palpitations, or dizziness; occasionally syncope or sudden cardiac death occurs. Correct diagnosis and risk stratification with respect to prophylactic ICD implantation are essential in HCM patient management. Drug therapy in symptomatic patients can be characterized as treatment of heart failure with preserved ejection fraction (HFpEF) in HNCM, while symptoms and the obstructive gradient in HOCM can be addressed with beta-blockers, disopyramide, or verapamil. After a short overview on etiology, natural history, and diagnostics in hypertrophic cardiomyopathy, this paper reviews the current treatment options for HOCM with a special focus on percutaneous septal ablation. Literature data and the own series of about 600 cases are discussed, suggesting a largely comparable outcome with respect to procedural mortality, clinical efficacy, and long-term outcome.