Implantable Cardioverter-defibrillator Implantation In Patients Research Articles

Efficacy and safety of implantable cardioverter-defibrillator implantation in the elderly—The I-70 Study: A randomized clinical trial

There is conflicting evidence on the efficacy of primary prevention implantable cardioverter-defibrillator (ICD) implantation in the elderly. The purpose of this study was to determine the efficacy and safety of ICD implantation in patients 70 years and older. Patients (n = 167) aged 70 years or older and eligible for ICD implantation were randomly assigned (1:1) to receive either optimal medical therapy (OMT) (n = 85) or OMT plus ICD (n = 82). Of the 167 participants (mean age 76.4 years; 165 men), 144 completed the study protocol according to their assigned treatment. Average participant follow-up was 31.5 months. Mortality was similar between the 2 groups: 27 deaths in OMT vs 26 death in ICD (unadjusted hazard ratio 0.92; 95% confidence interval 0.53-1.57), but there was a trend favoring the ICD over the first 36 months of follow-up. Rates of sudden death (7 vs 5; P = .81) and all-cause hospitalization (2.65 events per participant in OMT vs 3.09 in ICD; P = .31) were not statistically significantly different. Eleven participants randomized to ICD received appropriate therapy. Five participants received an inappropriate therapy that included at least 1 ICD shock. The study did not recruit to target sample size, and accumulated data did not show benefit of ICD therapy in patients 70 years or older. Future studies similar in design might be feasible but will need to contend with patient treatment preference given the large number of patients who do not want an ICD implanted. Further research is needed to determine whether the ICD is effective in prolonging life among elderly device candidates.

Assessment of ICD eligibility in non-ischaemic cardiomyopathy patients: aposition statement by the Task Force of the Dutch Society of Cardiology.

International guidelines recommend implantation of an implantable cardioverter-defibrillator (ICD) in non-ischaemic cardiomyopathy (NICM) patients with aleft ventricular ejection fraction (LVEF) below 35% despite optimal medical therapy and alife expectancy of more than 1year with good functional status. We propose refinement of these recommendations in patients with NICM, with careful consideration of additional risk parameters for both arrhythmic and non-arrhythmic death. These additional parameters include late gadolinium enhancement on cardiac magnetic resonance imaging and genetic testing for high-risk genetic variants to further assess arrhythmic risk, and age, comorbidities and sex for assessment of non-arrhythmic mortality risk. Moreover, several risk modifiers should be taken into account, such as concomitant arrhythmias that may affect LVEF (atrial fibrillation, premature ventricular beats) and resynchronisation therapy. Even though currently no valid cut-off values have been established, the proposed approach provides amore careful consideration of risks that may result in withholding ICD implantation in patients with low arrhythmic risk and substantial non-arrhythmic mortality risk.

Rationale and study protocol for the BRITISH randomized trial (Using cardiovascular magnetic resonance identified scar as the benchmark risk indication tool for implantable cardioverter defibrillators in patients with nonischemic cardiomyopathy and severe systolic heart failure)

BackgroundFor patients with nonischemic cardiomyopathy (NICM), current guidelines recommend implantable cardioverter defibrillators (ICD) when left ventricular ejection fraction (LVEF) is ≤35%, but the DANISH trial failed to confirm that ICDs reduced all-cause mortality for such patients. Circumstantial evidence suggests that scar on CMR is predictive of sudden and arrhythmic death in this population. The presence of myocardial scar identified by cardiac magnetic resonance imaging (CMR) in patients with NICM and an LVEF ≤35% might identify patients at higher risk of sudden arrhythmic death, for whom an ICD is more likely to reduce all-cause mortality. Methods/DesignThe BRITISH trial is a prospective, multicenter, randomized controlled trial aiming to enrol 1,252 patients with NICM and an LVEF ≤35%. Patients with a nonischemic scar on CMR will be randomized to either: (1) ICD, with or without cardiac resynchronization (CRT-D), or (2) implantable loop recorder (ILR) or cardiac resynchronization (CRT-P). Patients who are screened for the trial but are found not to be eligible, predominantly due to an absence of scar or those who decline to be randomized will be enrolled in an observational registry. The primary endpoint is all-cause mortality, which we plan to assess at 3 years after the last participant is randomized. Secondary endpoints include clinical outcomes, appropriate and inappropriate device therapies, symptom severity and well-being, device-related complications, and analysis of the primary endpoint by subgroups with other risk markers. ConclusionThe BRITISH trial will assess whether the use of CMR-defined scar to direct ICD implantation in patients with NICM and an LVEF ≤35% is associated with a reduction in mortality.

P411 THE ROLE OF CARDIAC MAGNETIC RESONANCE FOR ARRHYTHMIC RISK STRATIFICATION IN A PATIENT WITH MYOCARDITIS

Abstract Myocarditis is an inflammatory disease of cardiac muscle with a variable clinical presentation, ranging from asymptomatic cases to different degrees of left ventricular systolic dysfunction up to heart failure and dilated heart disease. Ventricular arrhythmias (VA) can occur in patients with myocarditis and implantable cardioverter defibrillator (ICD) may be indicated in patients with life–threatening VA who are not in the acute phase of myocarditis and who are receiving optimal medical therapy. Reduced left ventricular ejection fraction (LVEF) below 35%, which is used as the main criterion for stratifying the risk of sudden cardiac death (SCD), has low sensitivity and low specificity for arrhythmic risk stratification in patients with myocarditis. Myocardial scar is the main determinant for VA in these patients. Cardiac magnetic resonance imaging (CMR), using late gadolinium enhancement(LGE), has an excellent ability to determinate the extension and characterization of myocardial scar, indeed CMR can potentially improve SCD risk stratification and indication for ICD implantation in patients with myocarditis. We present a case of a 36 years–old male presenting to the Emergency Department with a monomorphic sustained ventricular tachycardia in whom MRI revealed myocardial–pericardial recurrent inflammatory involvement and worsening disease progression. ICD was implanted in consideration of the high risk of life–threatening arrhythmias.

The Relevance of Preventive Implantable Cardioverter-Defibrillators (ICDs) in Non-Ischemic Cardiomyopathy in the Presence of Effective Quadruple Therapy for Heart Failure: A Review of Contemporary Medical Literature.

Cardiomyopathy is a disease of the cardiomyocytes that affects their structural function, leading to heart failure (HF). Non-ischemic cardiomyopathy (NICM) includes a subtype of dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), and hypertrophic cardiomyopathy (HCM). These types of cardiomyopathies have no coronary artery vessel involvement. The most common cause of NICM is DCM. In the ischemic cardiomyopathy (ICM) subtype, the utilization of implantable cardioverter-defibrillators (ICDs) has been effective in the prevention of sudden cardiac death (SCD). However, the relevance of ICDs in patients with NICM having an ejection fraction (EF) ≤35%, who are also receiving effective quadruple therapy (i.e., angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB), beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter-2 (SGLT2) inhibitors)for HF has been a topic of debate.The purpose of this review is to analyze the benefits of preventive ICDs in NICM patients on adequate quadruple therapy for HF. The current guidelines recommend ICD implantation in patients with NICM who have a left ventricular ejection fraction of ≤35%, come under the New York Heart Association (NYHA) class II or III, andare in sinus rhythm with optimal medical therapy. The evidence supporting this recommendation islimited. Numerous clinical studies and meta-analyses have been conducted to look into this issue. While some have discovered a substantial decrease in mortality with the implantation of an ICD in patients with NICM, others have not found significant changes.Thereby, further investigations are required to define the function of ICDs in this population.

An implantable cardioverter-defibrillator for primary prevention in non-ischemic cardiomyopathy: A systematic review and meta-analysis.

Recent data regarding the comparison of implantable cardioverter-defibrillator (ICD) therapy and optimal medical treatment in patients with non-ischemic cardiomyopathy has indicated no mortality benefit as a result of ICD therapy. Although the recommendations for ICD implantation did not change, it is worth noting that these findings significantly affected the daily practice of ICD implantation in Europe. To assess the effect of ICD implantation in comparison to pharmacotherapy in the non- -ischemic cardiomyopathy heart failure population through a systematic review and meta-analysis of the available carefully designed prospective randomized controlled trials. Only prospective randomized controlled trials comparing ICD implantation in primary prevention vs. optimal pharmacological therapy or placebo and reporting mortality results were included in the meta-analysis. The authors have chosen to include the following trials: CAT, AMIOVIRT, DEFINITE, and DANISH. A meta-analysis of pooled hazard ratios (HR) from all trials conducted on a total of 1789 patients found that ICD therapy decreased all-cause mortality in comparison to optimal pharmacological treatment, with a HR of 0.48 (95% confidence interval [CI] 0.67-1.01); p = 0.06. The data from the AMIOVIRT, DANISH, and DEFINITE trials, with a total of 1677 participants, showed a significant reduction of sudden cardiac deaths as a result of ICD implantation, with a HR of 0.48 (95% CI 0.31-0.67); p < 0.001. In comparison with optimal medical treatment, ICD implantation in patients with heart failure improves the long-term prognosis in terms of sudden cardiac death, with a strong tendency towards all-cause mortality reduction.

Can the Norton Scale Score Be Used as an Adjunct Tool for Implantable Defibrillator Patient Selection? A Retrospective Single-Center Cohort Study.

(1) Background: Implantable cardioverter defibrillators (ICDs) have become the standard of care in the prevention of sudden cardiac death, yet studies have shown that competing causes of death may limit ICD benefits. The Norton scale is a pressure ulcer risk score shown to have prognostic value in other fields. The purpose of this study was to assess the use of the Norton scale as an aid for ICD patient selection; (2) Methods: The study was comprised of consecutive patients who underwent defibrillator implantation at Sheba Medical Center between 2008 and 2016. A competing risk analysis was performed to assess the likelihood of death prior to device therapy; (3) Results: 695 patients were included. A total of 59 (8.5%) patients had low admission Norton scale score (ANSS) (≤14), 81 (11.7%) had intermediate ANSS (15−17), and the remainder (79.8%) had high (18−20) ANSS. The cumulative probability of all-cause mortality within one year of ICD implantation in patients with low ANSS was 30%, compared with 20% and 7% among the intermediate- and high-ANSS groups, respectively. Moreover, the one-year mortality rate without ICD therapy in low-ANSS patients was over four-fold compared with that of high-ANSS patients (33% versus 7%, p < 0.0001); (4) Conclusions: The Norton scale could be a useful additional tool in predicting the life expectancy of ICD candidates, thereby improving patient selection.

Abstract 13009: Time to Implantable Cardioverter Defibrillator in Patients With Left Ventricular Ejection Fraction ≤ 35%

Background: Implantable cardioverter-defibrillators (ICDs) are endorsed by the current American Heart Association (AHA) Guidelines as the cornerstone in the primary prevention of mortality in patients with reduced ejection fraction (EF) (≤35%). The timing for ICD therapy in non-ischemic cardiomyopathy (NICM) is not specified in the current guidelines. The objective of this study was to determine the timing for ICD insertion for patients with NICM versus ICM in the real-world population. Methods: Retrospective design study of patients with ICDs implantation from 2019 to 2022 at our community hospital. Data was obtained via the Device Implant Registry. All eligible participants had confirmed diagnosis of ICM and NICM on chart review; while confirmed EF≤35% on echocardiography. Categorical predictors and clinical outcomes were analyzed using Pearson’s chi-square test or Fisher’s exact test. Quantitative predictors and clinical outcomes were analyzed using Student's t-test or the Wilcoxon rank sum test. Results: Our cohort included 62 patients undergoing ICD placement for primary prevention. There was no statistical significance between patients based on age, sex, race, and EF. Average time to ICD placement was 134 days for patients with ICM and 274 days for patients with NICM, a difference that favoured NICM; p =0.009 ( p &lt;0.05). In the majority of patients, 64.5%, ICD implantation was deferred for at least 90 days compared to 35.5% patients who had an ICD placed by 90 days; p =0.001 ( p &lt;0.05). The mortality in our study was 13% over a median of 2 years, with a predominance of ICM as compared to NICM, 75% versus 25%, respectably. Logistics regression demonstrated that timing to ICD implantation was not an independent variable of mortality. The mean overall survival was 274.4 days (SD +/- 50) in NICM compared to 134.3 days (SD +/- 21) in the ICM group, p =0.007 ( p &lt;0.05). Conclusions: In a real-world population, time to ICD implantation was statistically different in ICM compared to NICM. ICM remains a significant risk of all-cause mortality despite the progress made in both medical and procedural treatments. Further studies are necessary to determine the appropriate time to ICD implantation in patients with NICM and reduced EF.

Efficacy and safety of the ICD in patients with catecholaminergic polymorphic ventricular tachycardia

Abstract Background Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a potentially fatal genetic arrhythmia syndrome and, despite optimal beta-blocker (BB) therapy, patients often experience life-threatening arrhythmic events (LAE). The role of implantable cardioverter defibrillators (ICD) on reducing mortality in patients with CPVT is debated. Purpose 1) To assess the survival benefit of ICD in the overall CPVT population; 2) to investigate the benefit-to-harm ratio in the population of CPVT patients carriers of ICD. Methods We followed-up consecutive patients with genetically-proven CPVT, treated with optimal BB mono-therapy. The probability of surviving at the occurrence of a first LAE (defined as: sudden cardiac death, aborted cardiac arrest or hemodynamically non-tolerated ventricular tachycardia) during BB mono-therapy was compared between ICD carriers and non-ICD carriers. In the cohort of ICD carriers, we assessed the rate of a first major complication (i.e., a complication requiring surgical intervention) and we calculated the benefit-to-harm ratio of ICD (defined as rate of appropriate shocks on LAE over rate of major complications). Results We enrolled 228 CPVT patients with a pathogenic RYR2 (n=216) or CASQ2 (n=12) mutation, of whom 87 (38%) had an ICD implanted. Overall, during 1,558 person-years of follow-up, 31/228 (14%) patients experienced a first LAE on BB mono-therapy (annual LAE rate 2.0%, 95% CI: 1.4–2.8%). Of the 31 individuals who experienced an LAE, 21 patients had an ICD when the LAE occurred, and all survived after ICD intervention. Of the remaining 10 patients who were not carriers of an ICD, 6/10 (60%) survived after external defibrillation or spontaneous arrhythmia termination, while 4/10 (40%) died suddenly. The probability of surviving at the occurrence of a first LAE in BB mono-therapy was thirty-fold higher (Odds Ratio: 30.0, 95% CI: 1.4–629.0; p=0.029) in patients with an ICD, as compared to patients without an ICD. Overall, 15/87 (17%) patients with an ICD experienced a first major complication over 602 person-years of follow-up (2.5% per year, 95% CI: 1.4%-4.1%). Importantly, no patient died for a pro-arrhythmic effect or complications related to ICD. Comparing the rate of major complications to the rate of appropriate ICD shocks on LAE (LAE rate 4.7% per year, 95% CI: 3.1–7.0%), the benefit-to-harm ratio was 1.9, thus favouring the benefit of ICD therapy. Conclusions In our population, ICD therapy conferred a significant survival benefit in patients with CPVT at the occurrence of a first LAE. Overall, the benefit of ICD implant outweighed the harm, as shown by almost two times greater benefit-to-harm ratio. This study provides evidence supporting ICD implantation in patients with high-risk CPVT. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ricerca Corrente Funding Scheme of the Italian Ministry of Health

ECG as a risk stratification tool in patients with wearable cardioverter-defibrillator

BackgroundThe wearable cardioverter defibrillator (WCD) is increasingly used in patients at elevated risk for ventricular arrhythmias but not fulfilling the indications for an implantable cardioverter defibrillator (ICD). Currently, there is an insufficient risk prediction of fatal arrhythmias in patients at risk. In this study, we assessed the prognostic role of baseline electrocardiogram (ECG) in WCD patients. MethodsWCD patients from diverse clinical institutions in Germany (n = 227) were retrospectively enrolled and investigated for the incidences of death or ventricular arrhythmias during WCD wearing. In addition, the widely accepted ECG predictors of adverse outcome were analyzed in patients with arrhythmic events. ResultsLife-threatening arrhythmias occurred in 22 (9.7 %) patients, mostly in subjects with ischemic heart disease (15 of 22). There was no difference in baseline left ventricular ejection fraction (LVEF) in subjects with and without arrhythmic events (31.3 ± 7.9 % vs. 32.6 ± 8.3 %; p = 0,24). Patients with arrhythmia exhibited significantly longer QRS duration (109.5 ± 23.1 ms vs. 100.6 ± 22.3 ms, p = 0,04), Tpeak-Tend (Tp-e) (103.1 ± 15.6 ms vs. 93.2 ± 19.2 ms, p = 0,01) and QTc (475.0 ± 60.0 ms vs. 429.6 ± 59.4 ms, p < 0,001) intervals. In contrast, no significant differences were found for incidences of fragmented QRS (27.3 % vs. 24 %, p = 0.79) and inverted/biphasic T-waves (16.6 % vs. 22.7 %, p = 0,55). In multivariate regression analysis both Tp-e (HR 1.03; 95 % CI 1.001–1.057; p = 0.02) and QTc (HR 1.02; 95 % CI 1.006–1.026; p < 0.001) were identified as independent predictors of ventricular arrhythmias.After WCD use, the prophylactic ICD was indicated in 76 patients (33 %) with uneventful clinical course but persistent LVEF ≤35 %. The ECG analysis in these subjects did not reveal any relevant changes in arrhythmogenesis markers. ConclusionsECG repolarization markers Tp-e and QTc are associated with malignant arrhythmias in WCD patients and may be used - in addition to other established risk markers - to identify appropriate patients for ICD implantation.

Prevention of sudden death in heart failure with reduced ejection fraction: do we still needan implantable cardioverter-defibrillator for primary prevention?

Sudden death is a devastating complication of heart failure (HF). Current guidelines recommend an implantable cardioverter-defibrillator (ICD) for prevention of sudden death in patients with HF and reduced ejection fraction (HFrEF) specifically those with a left ventricular ejection fraction ≤35% after at least 3 months of optimized HF treatment. The benefit of ICD in patients with symptomatic HFrEF caused by coronary artery disease has been well documented; however, the evidence for a benefit of prophylactic ICD implantation in patients with HFrEF of non-ischaemic aetiology is less strong. Angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta-blockers (BB), and mineralocorticoid receptor antagonists (MRA) block the deleterious actions of angiotensin II, norepinephrine, and aldosterone, respectively. Neprilysin inhibition potentiates the actions of endogenous natriuretic peptides that mitigate adverse ventricular remodelling. BB, MRA, angiotensin receptor-neprilysin inhibitor (ARNI) have a favourable effect on reduction of sudden cardiac death in HFrEF. Recent data suggest a beneficial effect of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in reducing serious ventricular arrhythmias and sudden cardiac death in patients with HFrEF. So, in the current era of new drugs for HFrEF and with the optimal use of disease-modifying therapies (BB, MRA, ARNI and SGLT2i), we might need to reconsider the need and timing for use of ICD as primary prevention of sudden death, especially in HF of non-ischaemic aetiology.

EE432 Cost-Effectiveness Analysis of Sacubitril/Valsartan in Implantable Cardioverter-Defibrillator Eligible Patients

Sacubitril/valsartan has been shown to improve ejection fraction and has beneficial ventricular remodeling effect. Thus, the need for an implantable cardioverter-defibrillator (ICD) implantation may be reduced. Herein, we evaluated the cost-effectiveness of sacubitril/valsartan in reducing the need for an ICD implantation in patients with Heart failure with reduced ejection fraction (HFrEF).

Programmed ventricular stimulation for risk stratification in patients with myocardial scarring and an ejection fraction above or equal to 40%

Abstract Funding Acknowledgements Type of funding sources: None. Background Sudden cardiac death (SCD) is one of the leading causes of death, particularly among patients with myocardial scars. Implantable cardioverter defibrillators (ICD) are recommended in patients with a left ventricular ejection fraction (LVEF) ≤ 35%. Another recognised indication is the induction of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) during programmed ventricular stimulation (PVS) in post-myocardial infarction patients with non-sustained VT and a LVEF between 35% and 40%. However, no recommendation exists to guide the use of prophylactic ICD implantation in patients with less altered LVEF, even though they represent the majority of SCDs. Purpose We aimed to evaluate the prognostic value of PVS in patients with myocardial scars and a relatively preserved LVEF (≥ 40%). Methods Patients with evidence of a chronic myocardial scar and a LVEF ≥ 40%, who underwent PVS at two hospital centers were considered for inclusion. Ischemic and non-ischemic myocardial scars were included. The primary endpoint was the occurrence of a Major Arrhythmic Event (MAE), namely SCD, clinical VT/ventricular fibrillation, or appropriate ICD therapy. Results 134 patients were included (mean age 62.4 ± 12.5 years, LVEF 54.7 ± 8.6 %). Indication for PVS was mostly non-sustained VT and/or syncope (84%). Post-myocardial infarction patients represented about half of the cases (53%). Inducibility during PVS was observed in 17 patients (13%). There was a nonsignificant trend towards higher inducibility rates in ischemic versus nonischemic scars (17% and 8%, respectively; p-value = 0.1). Of these patients, 15 received an ICD (88%). Over a mean follow-up of 49 (±42) months, a MAE occurred in 7 patients (41.2%) with positive PVS, versus 4 patients (3.4%) with negative PVS. MAE-free survival at 10 years was 91% and 43% in PVS-negative and PVS-positive patients, respectively (p-value &amp;lt; 0.001). One SCD occurred in a PVS-positive patient who denied prophylactic ICD implantation. Inducibility during PVS provided a 64% sensitivity and a 97% negative predictive value (PV) to predict the occurrence of MAE (specificity 92%, positive PV 41%). Conclusion PVS is a useful tool to discriminate patients with myocardial scars and LVEF ≥ 40% at increased arrhythmic risk. Effective utilisation of ICD may be anticipated in case of positive PVS, while non-inducible patients are at lower MAE risk.

Effectiveness of Implantable Cardioverter-Defibrillators to Reduce Mortality in Patients With Long QT Syndrome

BackgroundThe effectiveness of implantable cardioverter-defibrillators (ICDs) on reducing mortality has not been well studied in patients with long QT syndrome (LQTS). ObjectivesThis study aimed to assess the survival benefits of ICDs in the overall LQTS population and in subgroups defined by ICD indications. MethodsThis study included 3,035 patients (597 with ICD) from the Rochester LQTS Registry with a QTc ≥470 milliseconds or confirmed LQTS mutation. Using multivariable Cox proportional hazards models, the risk of all-cause mortality, all-cause mortality before age 50 years, and sudden cardiac death (SCD) were estimated as functions of time-dependent ICD therapy. Indication subgroups examined included patients with: 1) nonfatal cardiac arrest; 2) syncope while on beta-blockers; and 3) a QTc ≥500 milliseconds and syncope while off beta-blockers. ResultsDuring the 118,837 person-years of follow-up, 389 patients died (137 before age 50 years, and 116 experienced SCD). In the entire population, patients with ICDs had a lower risk of death (HR: 0.54; 95% CI: 0.34-0.86), death before age 50 years (HR: 0.29; 95% CI: 0.14-0.61), and SCD (HR: 0.22; 95% CI: 0.09-0.55) than patients without ICDs did. Patients with ICDs also had a lower risk of mortality among the 3 indication subgroups (HR: 0.14; 95% CI: 0.06-0.34; HR: 0.27; 95% CI: 0.10-0.72; and HR: 0.42; 95% CI: 0.19-0.96, respectively). ConclusionsICD therapy was associated with a lower risk of all-cause mortality, all-cause mortality before age 50 years, and SCD in the LQTS population, as wells as with a lower risk of all-cause mortality in indication subgroups. This study provides evidence supporting ICD implantation in patients with high-risk LQTS.

B-PO03-169 MYOCARDIAL SCAR BURDEN QUANTIFIED BY CARDIAC MAGNETIC RESONANCE IMAGING IS PREDICTIVE OF VENTRICULAR TACHYCARDIA IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

Patients with hypertrophic cardiomyopathy (HCM) are at a higher risk of developing ventricular tachycardia (VT) and sudden cardiac death (SCD). Previous studies have demonstrated a correlation between late gadolinium enhancement (LGE) measured by cardiac magnetic resonance imaging (MRI) quantified as % of myocardial mass and VT; however, the predictive value of a more practical and routinely performed semi-quantitative assessment of LGE remains unknown. To determine whether a semi-quantitative assessment of myocardial fibrosis by cardiac MRI (number of myocardial segments with LGE) is predictive of VT in patients with HCM. We identified 65 patients (mean age 47±17, 34% female) with a clinical diagnosis of HCM who had a cardiac MRI prior to an implantable cardioverter defibrillator (ICD) implantation for primary prevention of SCD. VT was defined as appropriate anti-tachycardia pacing or shocks for sustained ventricular arrhythmias. The MRI was analyzed by an experienced radiologist blinded to the clinical data. LGE was assessed by both quantitative (% of total myocardial mass) and semi-quantitative (number of myocardial segments involved) methods. During the follow-up period (median 33 months), seven patients experienced VT. Patients with > 6 myocardial segments with LGE were at higher risk to develop VT (OR: 5.7, p=0.03) which remained significant after adjusting for age, maximum left ventricular wall thickness, left atrial size, maximum left ventricular outflow gradient, history of nonsustained VT, unexplained syncope, and family history of SCD (p=0.03). Similarly, patients with a higher fibrosis burden (LGE >10% myocardial mass) were more likely to develop VT (OR: 8.6, p=0.01) even after adjusting for the abovementioned traditional risk factors (p=0.04). The extent of LGE, assessed by both quantitative and semi-quantitative measures, is strongly associated with ventricular arrhythmias requiring ICD therapy in patients with HCM even after accounting for traditional risk factors. Fibrosis burden as detected by cardiac MRI may serve as an imaging biomarker to improve risk stratification and patient selection for primary prevention ICD implantation in patients with HCM.

Cardiovascular implantable electronic devices in hemodialysis patients: an updated review.

Cardiovascular diseases are the leading life-threatening complications in hemodialysis patients. In this scenario, both tachy-arrhythmias and brady-arrhythmias are involved with related hemodialysis and nonhemodialysis-dependent mechanisms; moreover, those arrhythmias usually occur in different time intervals before sudden cardiac death (SCD). Furthermore, current evidence shows that the presence of advanced chronic kidney disease (CKD) reduces the benefits of implantable cardioverter--defibrillators (ICDs), which increases the risk of both arrhythmic and nonarrhythmic death, especially in patients with advanced stages of heart failure. Notably, patients with advanced CKD show a more severe degree of heart failure compared with mild CKD patients. However, the benefits of the ICD implantation in the primary prevention of hemodialysis patients is still controversial, and by now, no significant benefits have emerged compared with nonhemodialysis-dependent CKD patients. In secondary prevention, hemodialysis patients with ICD implantation have higher mortality rates compared with nonhemodialysis-dependent CKD patients with ICD. On the other hand, most articles include hemodialysis patients with reduced left ventricular ejection fraction, neglecting those with preserved systolic function. This review focuses on the epidemiology of SCD in the setting of hemodialysis and the current evidence on ICD implantation in patients on hemodialysis therapy analyzing novel strategies, which might reduce the risk of ICD placing.

The Necessity of an ICD-Therapy in Patients with Indications for Primary Prevention of Sudden Cardiac Death. One Center Experience.

Aim Analysis of responses of cardioverter-defibrillators implanted in patients with cardiomyopathies (CMPs) of various origins and a high risk of sudden cardiac death (SCD) to assess the effectiveness of a modern strategy for primary prevention of SCD.Material and methods In the Federal Center for High Medical Technologies in Kaliningrad from 2014 through 2018, implantable cardioverter-defibrillators (ICD) and cardiac resynchronization therapy defibrillators (CRT-D) were installed in 165 patients. Major indications for device implantation in these patients included left ventricular (LV) systolic dysfunction with ejection fraction (EF) ≤35 %; chronic heart failure (CHF) consistent with the New York Heart Association (NYHA) functional class (FC) II-III (IV for CRT-D) without previous episodes of life-threatening ventricular arrhythmias, circulatory arrest and resuscitation, which was consistent with the current international strategy for primary prevention of SCD. The study patients were divided into two groups based on the CMP origin; group 1 included 101 (61.2 %) patients with CMP of ischemic origin (ICMP) and group 2 consisted of 64 (38.8 %) patients with CMP of non-ischemic origin (NCMP). Information about arrhythmic episodes and device activation was retrieved from the device electronic memory during visits of patients to the clinic and was also transmitted to the clinic by a remote monitoring system. This information was studied and evaluated for the validity and effectiveness of the device triggering. If necessary, the parameters of detection and treatment were adjusted taking into account the obtained information. Information was analyzed and statistically processed with the SPSS Statistics 20.0 software.Results The patients were followed up for 28.3 ± 15.6 months, during which the devices delivered therapy to 55 (33.3%) patients of the entire group. In the ICMP group, the devices were activated in 44 (26.7 %) patients and in the NCMP group, the devices were activated in 11 (6.7 %) patients. In group 1 (ICMP), appropriate triggering was observed in 33 (20.0%) patients and inappropriate triggering was observed in 11 (6.7%) patients. In group 2 (NCMP), appropriate triggering was observed in 2 (1.2 %) patients and inappropriate triggering was observed in 9 (5.5 %) patients. The main cause of inappropriate triggering was atrial fibrillation (AF). 17 (10.3 %) patients with ICMP had sustained ventricular tachycardia (VT), which did not reach the detection frequency for ICD therapy; these VTs were only detected by devices and terminated spontaneously. Intragroup differences in the number of patients who received an appropriate treatment were statistically significant: 33 (32.6 %) in the ICMP group vs. 2 (3.1 %) in the NCMP group (р&lt;0.006). Differences in the number of patients who received an inappropriate treatment were not statistically significant although their number was greater in the NCMP group than in the ICMP group (9 (14.1 %) vs. 11 (10.9 %), р&gt;0.05).Conclusion A higher requirement for the ICD treatment was revealed in patients with ICMP compared to patients with NCMP. The low demand for the ICD treatment in patients with NCMP and the more frequent inappropriate actuation of the devices in this patient group due to AF allow a conclusion that the criteria for primary prevention of SCD with ICD (LV EF ≤35% and clinically significant CHF) are not equally effective indications for ICD implantation in patients with ICMP and NCMP. It can be assumed that life-threatening ventricular arrhythmias are evident in patients with NCMP before the development of hemodynamically significant LV dysfunction and CHF, which warrants further research in this direction.

The role of cardiac magnetic resonance for arrhythmic risk stratification in a patient with myocarditis

Myocarditis is an inflammatory disease of cardiac muscle with a variable clinical presentation, ranging from asymptomatic cases to different degrees of left ventricular systolic dysfunction up to heart failure and dilated heart disease. Ventricular arrhythmias (VA) can occur in patients with myocarditis and implantable cardioverter defibrillator (ICD) may be indicated in patients with life-threatening VA who are not in the acute phase of myocarditis and who are receiving optimal medical therapy. Reduced left ventricular ejection fraction (LVEF) below 35%, which is used as the main criterion for stratifying the risk of sudden cardiac death (SCD), has low sensitivity and low specificity for arrhythmic risk stratification in patients with myocarditis. Myocardial scar is the main determinant for VA in these patients. Cardiac magnetic resonance imaging (CMR), using late gadolinium enhancement(LGE), has an excellent ability to determinate the extension and characterization of myocardial scar, indeed CMR can potentially improve SCD risk stratification and indication for ICD implantation in patients with myocarditis. We present a case of a 36 years-old male presenting to the Emergency Department with a monomorphic sustained ventricular tachycardia in whom MRI revealed myocardial-pericardial recurrent inflammatory involvement and worsening disease progression. ICD was implanted in consideration of the high risk of life-threatening arrhythmias.

Mortality after implantable cardioverter defibrillators in dialysis patients: a nationwide study

Abstract Background Although randomized clinical trials have shown that implantable cardioverter defibrillators (ICDs) reduce mortality in selected patients, patients on dialysis are excluded from these trials. Thus, data on mortality risk after ICD implantation in these patients are sparse. Purpose To examine all-cause mortality in patients receiving an ICD according to dialysis status and to identify factors associated with all-cause mortality in patients on dialysis. Methods Using Danish nationwide registries from 2000–2017, all patients ≥18 years old undergoing first-time ICD implantation were included. Patients on dialysis were identified prior to ICD implantation and followed for up to five years. The cumulative incidence of all-cause mortality according to dialysis status was assessed. Factors associated with all-cause mortality after ICD implantation in dialysis patients were examined using multivariable Cox proportional hazard regression. Results A total of 14,681 ICD patients were identified, of which 218 (1.5%) were on dialysis prior to ICD implantation. Compared with ICD patients not on dialysis, those on dialysis were younger (median age 64 years [IQR: 58–70] vs. 66 years [IQR: 57–72], p=0.02), more likely to receive an ICD for secondary prophylaxis (69.7% vs 53.7%), and had more comorbidities including ischaemic heart disease (60.6% vs. 46.3%), diabetes (28.4% vs. 20.4%), and peripheral vascular disease (10.1% vs. 5.6%) (p for all &amp;lt;0.05). The median time to death among ICD patients on dialysis and not on dialysis were 1.3 years (IQR: 0.4–2.8 years] and 2.2 years [IQR: 1.0–3.5 years], respectively. One-year mortality among ICD patients on dialysis (13.0%) was significantly higher compared with ICD patients not on dialysis (4.7%), p&amp;lt;0.001 (Figure). Five-year mortality was significantly higher in ICD patients on dialysis than those not on dialysis (42.2% vs 23.6%), p&amp;lt;0.001 (Figure). Factors associated with increased risk of all-cause mortality among ICD patients on dialysis were age ≥65 years at time of implantation (reference: age &amp;lt;65 years) (HR 1.90 [95% CI: 1.13–3.19]), primary prophylactic ICD (HR 1.81 [95% CI 1.08–3.05]), and diabetes (HR 1.87 [95% CI 1.14–3.07]). Sex, ischaemic heart disease, heart failure, stroke, chronic obstructive pulmonary disease, and malignancy were not associated with the risk of mortality (p&amp;gt;0.05 for all). Cardiovascular causes of death were common both in patients with- and without dialysis, 69.6% and 60.0%, respectively. Conclusion Five-year mortality in ICD patients on dialysis was 42% and twice as high compared with ICD patients not on dialysis. Age ≥65 years, primary prophylactic indication, and diabetes were factors associated with increased mortality. Careful evaluation of the potential benefit from an ICD implantation in dialysis patients is important considering the overall high mortality rates. Funding Acknowledgement Type of funding source: None

The mortality outcome after implantable cardioverter-defibrillator implantation according to indication for implantation and underlying etiology: a Nationwide Cohort study

Abstract Background and objectives There are few nationwide data about the mortality outcome after implantable cardioverter-defibrillator (ICD) implantation. The aim of this study was to evaluate the mortality outcome after ICD implantation according to indication for implantation (primary vs. secondary prevention) and underlying etiology (non-ischemic vs. ischemic heart disease) with a nationwide cohort data of Korea. Methods During the period from January 1, 2008 to December 31, 2017, 3,558 patients (mean age, 67.7±11.4 years) with newly-implanted ICD who were aged 19 years or older were identified by 50-percents random sampling from the Korean National Health Insurance Service database. Results Patients with primary and secondary prevention ICD were 1,097 (30.8%) and 2,461 (69.2%), respectively. Patients with non-ischemic and ischemic heart disease were 2,487 (69.9%) and 1,071 (30.1%), respectively. Overall all-cause mortality was 20.4% during the follow-up period (mean 24 months). The mortality rates in patients with primary and secondary prevention ICD were 26.2% and 17.9%, respectively. The mortality rates in patients with non-ischemic and ischemic heart disease were 16.1% and 30.4%, respectively. In Kaplan-Meier estimates of survival according to both indication for implantation and underlying etiology, the best prognostic group was patients with secondary prevention ICD and having non-ischemic etiology. The worst prognostic group was patients with primary prevention ICD and having ischemic etiology. The survival probability was below 50% (45.2%) 5 years after ICD implantation in patients with primary prevention ICD and having ischemic etiology. Conclusions In Korean nationwide data, patients with primary prevention ICD and having ischemic etiology show the worst prognosis. About half of these patients died of any cause within five years. Funding Acknowledgement Type of funding source: None