Prophylactic ICD Research Articles

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.

Prognostic relevance of new onset arrhythmia and ICD shocks in primary prophylactic ICD patients.

The prognostic relevance of new onset arrhythmias compared to ICD shocks in ICD patients is not well known. Aim of the study was to evaluate the prognostic relevance of new onset atrial fibrillation (AF) or ventricular arrhythmias (VT/VF) compared to ICD shocks in primary prophylactic ICD-patients. A total of 622 of 1955 (32%) patients of the prospective single-centre ICD-registry Ludwigshafen with primary prophylactic ICD indication and sinus rhythm (SR) at baseline without history of AF were analyzed. All patients underwent an ICD implantation between 1992 and 2012. During the median follow-up time of 6years, 200 (32%) ICD patients developed new AF and 249 (40%) patients new VT/VF. There was an approximately 10% increase of 5-year mortality rate depending on the type of new onset arrhythmia (no arrhythmia 19%, new AF 28%, new VT 36% and new VF 55% 5-year mortality). In a multivariate analysis, new onset of AF or VT/VF was anindependent predictor for increased mortality whereas VT shocks and inappropriate ICD shocks were not. More than half of primary prophylactic ICD patients with SR at baseline develop new AF or VT/VF after 6years. New onset arrhythmias of AF and VT/VF are independent prognostic factors for increased mortality in primary prophylactic ICD patients. ICD shocks itself, inappropriate or appropriate, are not additionally associated with a worse outcome. These results support the hypothesis that in clinical practice rather the arrhythmia than the ICD shock itself is responsible for a deteriorated prognosis.

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.

Survival and arrhythmic risk among ischemic and non-ischemic heart failure patients with prophylactic implantable cardioverter defibrillator only therapy: A propensity score-matched analysis

BackgroundConcerns about the efficacy of prophylactic ICD in non-ischemic cardiomyopathy (NICM) heart failure (HF) patients are still present. We aimed to assess whether survival and arrhythmic risk were different among ischemic cardiomyopathy (ICM) and NICM ICD-only patients, along with specific predictors for mortality. MethodsHF patients undergoing ICD-only implant were extracted from the nationwide multicenter UMBRELLA registry. Arrhythmic events were collected by remote monitoring and reviewed by a committee of experts. Results782 patients (556 ICM; 226 NICM) were recruited: mean ejection fraction of 26.6%; 83.4% in NYHA class II-III; mean QRS duration of 108.9 ms (only 14.9% with QRS > 130 ms). After 4.35 years of mean follow-up, all-cause mortality rate was 4.2%/year. In propensity-score (PS) analysis no survival differences between ICM and NICM subgroups appeared (mortality rates: 19.4% vs. 20%, p = 0.375). Age (hazard ratio [HR] = 1.02, p = 0.009), diabetes (HR = 2.61, p ≤ 0.001), chronic obstructive pulmonary disease (HR = 2.13, p = 0.002), and previous HF (HR = 2.28, p = 0.027) correlated with increased mortality for the entire population, however atrial fibrillation (AF) (HR = 2.68, p = 0.002) and chronic kidney disease (HR = 3.74, p ≤ 0.001) emerged as specific predictors in NICM patients. At follow-up, 134 patients (17.1%) were delivered a first appropriate ICD therapy (5.1%/year) without significant differences between ICM and NICM patients in the PS analysis (17.6% vs. 15.8%, p = 0.968). ICD shocks were associated with a higher mortality (HR = 2.88, p < 0.001) but longer detection windows (HR = 0.57, p = 0.042) correlated with fewer appropriate therapies. ConclusionsMortality and arrhythmia free survival is similar among ICM and NICM HF patients undergoing ICD-only implant for primary prevention strategy.

P3451Electrocardiogram as a predictor of survival without appropriate shocks in primary prophylactic ICD patients: a retrospective multi-center study

P3451Electrocardiogram as a predictor of survival without appropriate shocks in primary prophylactic ICD patients: a retrospective multi-center study

Leftventricular apical aneurysm in hypertrophic cardiomyopathy as a risk factor for sudden death at any age.

In hypertrophic cardiomyopathy (HCM) aging has proved protective against sudden death (SD) risk and aggressive recommendations for prophylactic ICDs are uncommon in patients ≥60 years. Nevertheless, we present a patient with an unexpected but aborted sudden death event at the advanced age of 71 years due to a left ventricular apical aneurysm (LVAA) which has emerged as a novel SD marker. Subsequent reappraisal of the Tufts HCM database, specifically the 118 LVAA patients, showed that 36% of SD events occurred at ≥60 years. Of HCM patients ≥ 60 years, SD was 8-fold more common with aneurysm than without aneurysms (16%vs 2%; P<0.001). Risk in HCM with LVAA persists throughout life and senior LVAA patients should also be considered for primary prevention of SD with the ICD.

Differential multivariable risk prediction of appropriate shock versus competing mortality - A prospective cohort study to estimate benefits from ICD therapy

Background and objectiveWe prospectively investigated combinations of risk stratifiers including multiple EP diagnostics in a cohort study of ICD patients. MethodsFor 672 enrolled patients, we collected history, LVEF, EP study and T-wave alternans testing, 24-h Holter, NT-proBNP, and the eGFR. All-cause mortality and first appropriate ICD shock were predefined endpoints. ResultsThe 635 patients included in the final analyses were 63 ± 13 years old, 81% were male, LVEF averaged 40 ± 14%, 20% were inducible at EP study, 63% had a primary prophylactic ICD. During follow-up over 4.3 ± 1.5 years, 108 patients died (4.0% per year), and appropriate shock therapy occurred in n = 96 (3.9% per year). In multivariate regression, age (p < 0.001), LVEF (p < 0.001), NYHA functional class (p = 0.007), eGFR (p = 0.024), a history of atrial fibrillation (p = 0.011), and NT-pro-BNP (p = 0.002) were predictors of mortality. LVEF (p = 0.002), inducibility at EP study (p = 0.007), and secondary prophylaxis (p = 0.002) were identified as independent predictors of appropriate shocks. A high annualized risk of shocks of about 10% per year was prevalent in the upper quintile of the shock score. In contrast, a low annual risk of shocks (1.8% per year) was found in the lower two quintiles of the shock score. The lower two quintiles of the mortality score featured an annual mortality <0.6%. ConclusionsIn a prospective ICD patient cohort, a very good approximation of mortality versus arrhythmic risk was possible using a multivariable diagnostic strategy. EP stimulation is the best test to assess risk of arrhythmias resulting in ICD shocks.

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?

Predictors of mortality and ICD shock therapy in primary prophylactic ICD patients-A systematic review and meta-analysis.

BackgroundThere is evidence that the benefit of a primary prophylactic ICD therapy is not equal in all patients.PurposeTo evaluate risk factors of appropriate shocks and all- cause mortality in patients with a primary prophylactic ICD regarding contemporary studies.Data sourcePubMed, LIVIVO, Cochrane CENTRAL between 2010 and 2016.Study selectionStudies were eligible if at least one of the endpoints of interest were reported.Data extractionAll abstracts were independently reviewed by at least two authors. The full text of all selected studies was then analysed in detail.Data synthesisOur search strategy retrieved 608 abstracts. After exclusion of unsuitable studies, 36 papers with a total patient number of 47282 were included in our analysis. All-cause mortality was significantly associated with increasing age (HR 1.41, CI 1.29–1.53), left ventricular function (LVEF; HR 1.21, CI 1.14–1.29), ischemic cardiomyopathy (ICM; HR 1.37, CI 1.14–1.66) and co-morbidities such as impaired renal function (HR 2.30, CI 1.97–2.69). Although, younger age (HR 0.96, CI 0.85–1.09), impaired LVEF (HR 1.26, CI 0.89–1.78) and ischemic cardiomyopathy (HR 2.22, CI 0.83–5.93) were associated with a higher risk of appropriate shocks, none of these factors reached statistical significance.LimitationsIndividual patient data were not available for most studies.ConclusionIn this meta-analysis of contemporary clinical studies, all-cause mortality is predicted by a variety of clinical characteristics including LVEF. On the other hand, the risk of appropriate shocks might be associated with impaired LVEF and ischemic cardiomyopathy. Further prospective studies are required to verify risk factors for appropriate shocks other than LVEF to help select appropriate patients for primary prophylactic ICD-therapy.

Clinical outcome of patients with the Brugada type 1 electrocardiogram without prophylactic implantable cardioverter defibrillator in primary prevention: a cumulative analysis of seven large prospective studies.

AimsPatients with the Brugada type 1 ECG (Br type 1) without previous aborted sudden death (aSD) who do not have a prophylactic ICD constitute a very large population whose outcome is little known. The objective of this study was to evaluate the risk of SD or aborted SD (aSD) in these patients.Methods and resultsWe conducted a meta-analysis and cumulative analysis of seven large prospective studies involving 1568 patients who had not received a prophylactic ICD in primary prevention. Patients proved to be heterogeneous. Many were theoretically at low risk, in that they had a drug-induced Br type 1 (48%) and/or were asymptomatic (87%), Others, in contrast, had one or more risk factors. During a mean/median follow-up ranging from 30 to 48 months, 23 patients suffered SD and 1 had aSD. The annual incidence of SD/aSD was 0.5% in the total population, 0.9% in patients with spontaneous Br type 1 and 0.08% in those with drug-induced Br type 1 (P = 0.0001). The paper by Brugada et al. reported an incidence of SD more than six times higher than the other studies, probably as a result of selection bias. On excluding this paper, the annual incidence of SD/aSD in the remaining 1198 patients fell to 0.22% in the total population and to 0.38 and 0.06% in spontaneous and drug-induced Br type 1, respectively. Of the 24 patients with SD/aSD, 96% were males, the mean age was 39 ± 15 years, 92% had spontaneous Br type 1, 61% had familial SD (f-SD), and only 18.2% had a previous syncope; 43% had a positive electrophysiological study. Multiple meta-analysis of individual trials showed that spontaneous Br type 1, f-SD, and previous syncope increased the risk of SD/aSD (RR 2.83, 2.49, and 3.03, respectively). However, each of these three risk factors had a very low positive predictive value (PPV) (1.9–3.3%), while negative predictive values (NPV) were high (98.5–99.7%). The incidence of SD/aSD was only slightly higher in patients with syncope than in asymptomatic patients (2% vs. 1.5%, P = 0.6124). Patients with SD/aSD when compared with the others had a mean of 1.74 vs. 0.95 risk factors (P = 0.026).Conclusion(i) In patients with Br type 1 ECG without an ICD in primary prevention, the risk of SD/aSD is low, particularly in those with drug-induced Br type 1; (ii) spontaneous Br type 1, f-SD, and syncope increase the risk. However, each of these risk factors individually has limited clinical usefulness, owing to their very low PPV; (iii) patients at highest risk are those with more than one risk factor.

P6421Role of sudden cardiac death as end-stage complication in Fabry disease cardiomyopathy: Impact of primary and secondary prophylactic ICD therapy on long-term outcome

P6421Role of sudden cardiac death as end-stage complication in Fabry disease cardiomyopathy: Impact of primary and secondary prophylactic ICD therapy on long-term outcome

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

Sudden cardiac death in inherited cardiomyopathy

Cardiomyopathy is an important cause of sudden cardiac death particularly in adolescents and young adults. The risk of sudden cardiac death varies between individual cardiomyopathies and is dependent on the severity of disease, age and gender. Although rare in cardiomyopathies, a fundamental aspect of clinical management is a systematic and thorough clinical assessment to identify the small number of individuals who are at risk and who can be protected with prophylactic ICD therapy.

ECG score to predict ICD therapies in patients with nonischemic cardiomyopathy and primary prophylactic CRT-D

Recently published results of the DANISH study raise concerns, if primary prophylactic ICD implantations in patients with nonischemic cardiomyopathy (NICM) and severe reduced left ventricular ejection fraction (LVEF) should be performed without further risk stratification. There was no significant difference in the overall mortality of patients with or without ICD and CRT defibrillator (CRT-D) or CRT pacemaker (CRT-P), respectively. Clinical risk scores to identify patients with ischemic cardiomyopathy (ICM) who benefit most from an ICD have been recommended. The need for risk stratification systems concerning patients with NICM has been emphasized. A retrospective study of 434 consecutive patients with CRT-D implantation was performed. Patients with no regular follow-up at our institution (n= 132), secondary prophylactic ICD indication (n= 61), and upgrade to CRT (n= 95) were excluded. The occurrence of an adequate ICD therapy was defined as the endpoint. Left ventricular ejection fraction (LVEF), genesis of the cardiomyopathy as well as the modified Selvester ECG score (MSES) for evaluation of the left ventricular scar burden were documented among other characteristics. Within a median follow-up of 605 days, 24% of the patients experienced an adequate ICD therapy. These patients had significantly lower LVEF (20% vs. 23%), and the MSES was higher (7 vs. 3points). There was no significant difference in patients suffering from ICM vs NICM. Areceiver-operating-characteristic (ROC) analysis revealed asensitivity of 0.914 and aspecifity of 0.586 for MSES ≥4 to predict the occurrence of an ICD therapy. None of 35patients suffering from NICM with MSES <4 experienced an ICD therapy. The evaluation of the left ventricular scar burden using MSES can be useful for the decision between CRT-D and CRT-P in patients suffering from NICM.

In nonischemic systolic heart failure, prophylactic ICDs did not reduce all-cause mortality compared with usual care.

Source Citation Kober L, Thune JJ, Nielsen JC, et al; DANISH Investigators. Defibrillator implantation in patients with nonischemic systolic heart failure. N Engl J Med. 2016;375:1221-30. 27571011

Risk of sudden death in subjects with Brugada type 1 electrocardiographic pattern and no previous cardiac arrest: is it high enough to justify an extensive use of prophylactic ICD?

Risk of sudden death in subjects with Brugada type 1 electrocardiographic pattern and no previous cardiac arrest: is it high enough to justify an extensive use of prophylactic ICD?

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

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

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.