Prevention Of Sudden Cardiac Death Research Articles

Ventricular arrhythmia and sudden cardiac death in hypertrophic cardiomyopathy: From bench to bedside.

Patients with hypertrophic cardiomyopathy (HCM) mostly experience minimal symptoms throughout their lifetime, and some individuals have an increased risk of ventricular arrhythmias and sudden cardiac death (SCD). How to identify patients with a higher risk of ventricular arrythmias and SCD is the priority in HCM research. The American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) both recommend the use of risk algorithms to identify patients at high risk of ventricular arrhythmias, to be selected for implantation of implantable cardioverters/defibrillators (ICDs) for primary prevention of SCD, although major discrepancies exist. The present SCD risk scoring systems cannot accurately identify early-stage HCM patients with modest structural remodeling and mild disease manifestations. Unfortunately, SCD events could occur in young asymptomatic HCM patients and even as initial symptoms, prompting the determination of new risk factors for SCD. This review summarizes the studies based on patients' surgical specimens, transgenic animals, and patient-derived induced pluripotent stem cells (hiPSCs) to explore the possible molecular mechanism of ventricular arrhythmia and SCD. Ion channel remodeling, Ca2+ homeostasis abnormalities, and increased myofilament Ca2+ sensitivity may contribute to changes in action potential duration (APD), reentry circuit formation, and trigger activities, such as early aferdepolarization (EAD) or delayed afterdepolarization (DAD), leading to ventricular arrhythmia in HCM. Besides the ICD implantation, novel drugs represented by the late sodium current channel inhibitor and myosin inhibitor also shed light on the prevention of HCM-related arrhythmias. The ideal prevention strategy of SCD in early-stage HCM patients needs to be combined with gene screening, hiPSC-CM testing, machine learning, and advanced ECG studies, thus achieving individualized SCD prevention.

Impact of signal-averaged electrocardiography findings on appropriate shocks in prophylactic implantable cardioverter defibrillator patients with nonischemic systolic heart failure

BackgroundAppropriate shock therapy is associated with subsequent all-cause death in heart failure (HF) patients who receive an implantable cardioverter defibrillator (ICD) for the primary prevention of sudden cardiac death. To evaluate the impact of signal-averaged electrocardiography (SAECG) findings on appropriate shocks in prophylactic ICD patients with nonischemic systolic HF.MethodsWe studied 86 patients with nonischemic HF and a left ventricular ejection fraction ≤ 35% who underwent new ICD implantation for the primary prevention of sudden cardiac death. We excluded patients who had a previously implanted permanent pacemaker and patients who received cardiac resynchronization therapy with an ICD. SAECG was performed before implantation. Abnormal SAECG findings were defined if 2 of the following 3 conditions were identified: filtered QRS duration (fQRS) ≥ 114 ms, root-mean-square voltage during the last 40 ms of the fQRS (RMS 40) < 20 μV, and duration of the low-amplitude potentials < 40 μV (LAS 40) > 38 ms; additionally, patients with a QRS complex ≥ 120 ms who met both the RMS 40 and LAS 40 criteria were also considered to have abnormal SAECG findings. The primary outcome was the first occurrence of appropriate shock after implantation of the ICD. The secondary outcomes were the first occurrence of inappropriate shock and all-cause mortality.ResultsForty-two patients met the criteria for abnormal SAECG findings (49%). During a median follow-up period of 61 months, 17 patients (20%) died, 24 (28%) received appropriate shock therapy, and 19 (22%) received inappropriate shock therapy. There was a significantly higher incidence of appropriate shocks in patients with abnormal SAECG findings than in those with normal SAECG findings (log-rank test, p = 0.025). Multivariate analysis revealed that abnormal SAECG findings were independently associated with the occurrence of appropriate shock (hazard ratio 2.67, 95% confidential interval 1.14–6.26). However, abnormal SAECG findings were not related to inappropriate shock. There was no difference in the incidence of all-cause death between patients with abnormal and normal SAECG findings.ConclusionsOur results suggest that abnormal SAECG findings are associated with a high probability of appropriate shocks in prophylactic ICD patients with nonischemic systolic HF.

Sport Related Sudden Death: The Importance of Primary and Secondary Prevention.

Sports are a double-edged sword. On the one hand, cardiovascular benefits from sports activity are well-known, and on the other hand, sports may increase the risk of sudden cardiac death (SCD) in subjects with known or unknown cardiovascular diseases. SCD is rare but has a very strong emotional issue. There are many examples involving famous professional athletes, but this is only scratching the surface of a widespread phenomenon that also involves amateur athletes. The importance of safely performing physical activity appears clear in both professional and amateur athletes. In particular, the former undergo a pre-participation screening for SCD primary prevention with different recommendations in each country. On the other hand, a medical examination is not mandatory for non-professional athletes and, therefore, for people who practice sports as an amateur. Widespread distribution of automatic external defibrillators and people trained for cardiopulmonary resuscitation are necessary to promote secondary prevention of SCD. We briefly report a case series of athletes with aborted SCD during sports activity in order to underline and discuss in this review the previously highlighted issues.

Usefulness of the MADIT-ICD Benefit Score in a Large Mixed Patient Cohort of Primary Prevention of Sudden Cardiac Death.

Background: Decision-making in primary prevention is not always trivial and many clinical scenarios are not reflected in current guidelines. To help evaluate a patient’s individual risk, a new score to predict the benefit of an implantable defibrillator (ICD) for primary prevention, the MADIT-ICD benefit score, has recently been proposed. The score tries to predict occurrence of ventricular arrhythmias and non-arrhythmic death based on data from four previous MADIT trials. We aimed at examining its usefulness in a large single-center register of S-ICD patients with various underlying cardiomyopathies. Methods and results: All S-ICD patients with a primary preventive indication for ICD implantation from our large single-center database were included in the analysis (n = 173). During a follow-up of 1227 ± 978 days, 27 patients developed sustained ventricular arrhythmias, while 6 patients died for non-arrhythmic reasons. There was a significant correlation for patients with ischemic cardiomyopathy (ICM) (n = 29, p = 0.04) to the occurrence of ventricular arrhythmia. However, the occurrence of ventricular arrhythmias could not sufficiently be predicted by the MADIT-ICD VT/VF score (p = 0.3) in patients with (n = 142, p = 0.19) as well as patients without structural heart disease (n = 31, p = 0.88) and patients with LV-EF < 35%. Of the risk factors included in the risk score calculation, only non-sustained ventricular tachycardias were significantly associated with sustained ventricular arrhythmias (p = 0.02). Of note, non-arrhythmic death could effectively be predicted by the proposed non-arrhythmic mortality score as part of the benefit score (p = 0.001, r = 0.3) also mainly driven by ICM patients. Age, diabetes mellitus, and a BMI < 23 kg/m2 were key predictors of non-arrhythmic death implemented in the score. Conclusion: The MADIT-ICD benefit score adds a new option to evaluate expected benefit of ICD implantation for primary prevention. In a large S-ICD cohort of primary prevention, the value of the score was limited to patients with ischemic cardiomyopathy. Future research should evaluate the performance of the score in different subgroups and compare it to other risk scores to assess its value for daily clinical practice.

Prevention of heart failure, tachyarrhythmias and sudden cardiac death in HIV.

To summarize the state-of-the-art literature on the epidemiology, disease progression, and mediators of heart failure, tachyarrhythmias, and sudden cardiac death in people living with HIV (PLWH) to inform prevention strategies. Recent studies corroborate the role of HIV as a risk enhancer for heart failure and arrhythmias, which persists despite adjustment for cardiovascular risk factors and unhealthy behaviors. Immune activation and inflammation contribute to the risk. Heart failure occurs more frequently at younger ages, and among women and ethnic minorities living with HIV, highlighting disparities. Prospective outcome studies remain sparse in PLWH limiting prevention approaches. However, subclinical cardiac and electrophysiologic remodeling and dysfunction detected by noninvasive testing are powerful disease surrogates that inform our mechanistic understanding of HIV-associated cardiovascular disease and offer opportunities for early diagnosis. Aggressive control of HIV viremia and cardiac risk factors and abstinence from unhealthy behaviors remain treatment pillars to prevent heart failure and arrhythmic complications. The excess risk among PLWH warrants heightened vigilance for heart failure and arrhythmic symptomatology and earlier testing as subclinical abnormalities are common. Future research needs include identifying novel therapeutic targets to prevent heart failure and arrhythmias and testing of interventions in diverse groups of PLWH.

Arrhythmic risk prediction in arrhythmogenic right ventricular cardiomyopathy: external validation of the arrhythmogenic right ventricular cardiomyopathy risk calculator.

AimsArrhythmogenic right ventricular cardiomyopathy (ARVC) causes ventricular arrhythmias (VAs) and sudden cardiac death (SCD). In 2019, a risk prediction model that estimates the 5-year risk of incident VAs in ARVC was developed (ARVCrisk.com). This study aimed to externally validate this prediction model in a large international multicentre cohort and to compare its performance with the risk factor approach recommended for implantable cardioverter-defibrillator (ICD) use by published guidelines and expert consensus.Methods and resultsIn a retrospective cohort of 429 individuals from 29 centres in North America and Europe, 103 (24%) experienced sustained VA during a median follow-up of 5.02 (2.05–7.90) years following diagnosis of ARVC. External validation yielded good discrimination [C-index of 0.70 (95% confidence interval-CI 0.65–0.75)] and calibration slope of 1.01 (95% CI 0.99–1.03). Compared with the three published consensus-based decision algorithms for ICD use in ARVC (Heart Rhythm Society consensus on arrhythmogenic cardiomyopathy, International Task Force consensus statement on the treatment of ARVC, and American Heart Association guidelines for VA and SCD), the risk calculator performed better with a superior net clinical benefit below risk threshold of 35%.ConclusionUsing a large independent cohort of patients, this study shows that the ARVC risk model provides good prognostic information and outperforms other published decision algorithms for ICD use. These findings support the use of the model to facilitate shared decision making regarding ICD implantation in the primary prevention of SCD in ARVC.

Inequality between women and men in ICD implantation.

BackgroundThe impact of sex on ICD implantation practice and survival remain a topic of controversy. To assess sex-specific differences in ICD implantation practice we compared clinical characteristics and survival in women and men.MethodsFrom a nationwide registry, all new ICD implantations performed between 01/02/2010 and 31/01/2019 in Belgian patients were analyzed retrospectively. Baseline characteristics and survival rates were compared between sexes. To identify predictors of mortality, multivariable Cox regression was performed.ResultsOnly 3096 (20.9%) of 14,787 ICD implantations were performed in women. Within each type of underlying cardiomyopathy, the proportion women were lower than men. The main indication in men was ischemic vs dilated cardiomyopathy in women. Women were overall younger (59.1 ± 15.1 vs 62.6 ± 13.1 years; p < 0.001) and had less comorbidities except for oncological disease. More women functioned in NYHA-class III (33.6% vs 27.9%; p < 0.001) and had a QRS > 150 ms (29.4% vs 24.3%; p < 0.001), consistent with a higher use of CRT-D devices (31.7% vs 25.1%; p < 0.001). Women had more complications, reflected by the need to more re-interventions within 1 year (4.3% vs 2.7%, p < 0.001). After correction for covariates, sex-category was not a significant predictor of mortality (p = 0.055).ConclusionThere is a significant sex-disparity in ICD implantation rates, not fully explained by epidemiological differences in the prevalence of cardiomyopathies, which could imply an undertreatment of women. Women differ from men in baseline characteristics at implantation suggesting a selection bias. Further research is necessary to evaluate if women receive equal sudden cardiac death prevention.

Standardizing Optimal Medical Therapy in Heart Failure Patients to Improve NCDR Metrics for ICD Implantation

Purpose: The Heart Rhythm Society recommends two medications to be prescribed after an ICD (Implantable Cardioverter Defibrillator) implantation for patients with EF < 40%. The recommended medications are beta blockers and angiotensin converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) These medications have been well established as front line treatment in patients with heart failure who often need ICD implantation in prevention of sudden cardiac death. Long term beta blocker therapy can improve symptoms of heart failure, improve patient clinical status, and reduce hospitalizations and mortality.

Radiofrequency Ablation in Brugada Syndrome

In 1992, Brugada brothers first described the clinical-electrocardiographic syndrome which was characterized by changes in the electrocardiogram (ECG), family history of syncopal states and sudden cardiac death (SCD) in the absence of structural heart disease. The standard therapy recommended by the European Society of Cardiology for the prevention of SCD in type I Brugada syndrome (BS) is implantation of a cardioverter-defibrillator. Radiofrequency ablation (RFA) of BS has been performed since the 2000s as an alternative therapy for BS with recurrent ventricular arrhythmias. To date, more than 300 such interventions have been performed by various centers around the world, and multicenter randomized trials are underway to study the long-term results of catheter destruction. We reviewed our experience of catheter ablation in a patient with BS. The patient suffered from ventricular arrhythmias and short-term loss of consciousness. ECG and 24-hour monitoring data recorded ventricular arrhythmias of more than 34% per day and type II BS. Electroanatomical mapping and RFA of the areas with low amplitude graphics were performed by endocardial access. This zone coincided with the earliest activation of the myocardium during ventricular arrhythmias. Extrasystoles were eliminated. In the remote period (10-12 weeks) the patient had no ventricular arrhythmias and there are also no ECG signs of BS.&#x0D; Most major arrhythmological centers perform RFA with epicardial access. Our patient chose the endocardial approach as safer. In her specific case, localization of arimogenic substrate allowed to limit this access, and RFA was successful.

Role of Implantable Cardioverter Defibrillator in Heart Failure With Contemporary Medical Therapy.

Implantable cardioverter defibrillator therapy is indicated in a subset of patients with heart failure with reduced ejection as primary prevention for sudden cardiac death. The advent of novel medical therapies including mineralocorticoid receptor antagonists, angiotensin receptor blocker/neprilysin inhibitors, and sodium-glucose transporter 2 inhibitor in the past 2 decades has revolutionized heart failure with reduced ejection management. Current guideline-directed medical therapy has reduced all-cause mortality and sudden cardiac death and confers a considerable improvement in left ventricular ejection fraction over a short period of time. However, there is limited evidence at present to suggest whether implantable cardioverter defibrillator therapy continues to have the same benefit in sudden cardiac death prevention at current left ventricular ejection fraction cutoff indications for patients on contemporary guideline-directed medical therapy for heart failure with reduced ejection. In this review, the authors propose in lieu of current evidence that it is reasonable to reevaluate indications for implantable cardioverter defibrillator therapy in patients on contemporary guideline-directed medical therapy for heart failure with reduced ejection.

КЛИНИЧЕСКИЕ И МОЛЕКУЛЯРНО-ГЕНЕТИЧЕСКИЕ ОСНОВЫ ВНЕЗАПНОЙ СЕРДЕЧНОЙ СМЕРТИ ПРИ ПЕРВИЧНЫХ ЭЛЕКТРИЧЕСКИХ ЗАБОЛЕВАНИЯХ СЕРДЦА У ДЕТЕЙ

Primary electrical heart diseases (PEHDs) are hereditary orphan life-threatening conditions leading to a sudden cardiac death in young adults in the absence of structural heart disease. Among the most common and studied diseases of this group are: long QT syndrome (LQTS), catecholaminergic ventricular tachycardia, Brugada syndrome, short QT syndrome, early ventricular repolarization syndrome. Also, this group of diseases includes congenital sick sinus syndrome, progressive cardiac conduction defect, idiopathic ventricular fibrillation, familial atrial fibrillation and a number of cases (from 5 to 10%) of the sudden cardiac death syndrome in infants. The total prevalence of PEHDs in the pediatric population is quite high and is about 1:2000, mainly due to long QT syndrome. PEHDs are poorly identified by the standard clinical approach, at the same time a delay in diagnosing and prescribing specific therapy may lead to fatal consequences and sudden cardiac death of the child at the first-ever syncope. The vast majority of PEHDs genes identified to date encode subunits of cardiac ion channels or proteins, which interact with ion channels and regulate their functions. The advent of the next generation sequencing led to a shift in most DNA diagnostics laboratories from screening single genes or small gene panels to examining of whole exome or whole genome data. These diseases, especially LQTS, have become unique cardiological models for clinical and genetic studies, analysis of genotype-phenotype correlations and the development of a modern strategy of multi-level hybrid therapy and the prevention of sudden cardiac death (SCD) in people of young age. The most PEHDs can and should be diagnosed in childhood, which now makes it possible to effectively prevent life-threatening arrhythmias. More and more patients are surviving into adulthood, as yet, and patients are interacting with traditional risk factors and obviously should have higher cardiovascular risks. Due to the high prevalence in the population, the association with the SCD, the polymorphism of clinical and genetic manifestations, high technology medicine, the research of PEHDs has become one of the priority places in both pediatric and adult cardiology, and the diseases have now become models for development of gene therapies. The paper outlines the clinical and genetic characteristics, the basics of diagnostics and up-to-date therapeutic, interventional and surgical technologies for the treatment of the most common PEHDs in childhood.

Prevalence and Predisposing Factors of Non-infectious Cardiac Implantable Electronic Device Lead Masses as Incidental Finding During Transoesophageal Echocardiography: A Retrospective Cohort Study.

ObjectivesIn this study, we assessed the prevalence and predisposing factors of non-infectious CIED lead masses as incidental finding during transoesophageal echocardiography (TOE).MethodsIn a retrospective single centre study, we analysed TOE examinations performed for indications other than infectious endocarditis in 141 patients with CIED. Patients with non-suspicious leads and those with incidental non-infectious lead masses were compared with respect to clinical characteristics, anticoagulation, indication for TOE, and CIED lead characteristics. The odds ratios for non-infectious CIED lead masses were calculated.ResultsNon-infectious CIED lead masses were detected in 39 (27.6%) of the 141 patients. They were more often identified on ICD and CRT-D leads compared to pacemaker and CRT-P leads [OR 2.77 (95% CI 1.29–5.95), p = 0.008]. The lifespan of the CIEDs from the first implantation to the index TOE did not differ between both groups. Incidental CIED lead masses were more prevalent in patients who received their device for primary prevention of sudden cardiac death (43.2%) and for resynchronisation (63.6%) but were less prevalent in patients with oral anticoagulation [OR.33 (95% CI.003–1.003), p = 0.048].ConclusionIncidental non-infectious CIED lead masses were frequently found in TOE, with highest prevalence in ICD and CRT-D devices implanted for patients with dilated cardiomyopathy. Patients with therapeutic anticoagulation had significantly lower prevalence of CIED lead masses than those without.

Patients' knowledge and concerns about using the implantable cardioverter defibrillator for the primary prevention of sudden cardiac death and its correlates: A cross-sectional study.

Background and AimsSudden cardiac death (SCD) is one of the most common causes of mortality in heart failure (HF) patients with reduced ejection fraction. Patients have concerns about the disease and use the implantable cardioverter defibrillator (ICD) to reduce the effects of HF disease. The current study aims to evaluate the barriers and factors affecting the implantation of the ICD for primary prevention.MethodsOne hundred‐forty‐seven patients with HF were studied in public hospitals in southern Iran by using a cross‐sectional design from April 2018 to June 2019. Demographic, researcher‐made questionnaire, World Health Organization Quality of life‐BREF (WHOQOL‐BREF), general self‐efficacy questionnaires, and Multidimensional Scale of Perceived Social Support (MSPSS) were measured for investigating the barriers and impact factors in patent HF.ResultsMost participants were male (56.5%), married (88.4%), illiterate (54.1%), and unemployed (72.6%). 62.6% (n = 92) of the participants did not know about HF and ICD. The total score of patients' concerns about using ICD was 47.11 ± 11.26, which showed a moderate level. The scores of knowledge about HF and ICD had a significant positive poor correlation with self‐efficacy, perceived social support and QoL. Also, the score of concerns about the ICD had a significant negative poor correlation with perceived social support.ConclusionUnderstanding HF patients' issues and obstacles can help us prevent sudden death. Doctors' advice has a significant impact on patients' acceptance. Poor knowledge is the most important reason for nonparticipation. Intervention is necessary to inform patients to understand the advantages and disadvantages.

New avenues in the prevention of sudden cardiac death.

New avenues in the prevention of sudden cardiac death.

Pharmacologic Management for Ventricular Arrhythmias: Overview of Anti-Arrhythmic Drugs.

Ventricular arrhythmias (Vas) are a life-threatening condition and preventable cause of sudden cardiac death (SCD). With the increased utilization of implantable cardiac defibrillators (ICD), the focus of VA management has shifted toward reduction of morbidity from VAs and ICD therapies. Anti-arrhythmic drugs (AADs) can be an important adjunct therapy in the treatment of recurrent VAs. In the treatment of VAs secondary to structural heart disease, amiodarone remains the most well studied and current guideline-directed pharmacologic therapy. Beta blockers also serve as an important adjunct and are a largely underutilized medication with strong evidentiary support. In patients with defined syndromes in structurally normal hearts, AADs can offer tailored therapies in prevention of SCD and improvement in quality of life. Further clinical trials are warranted to investigate the role of newer therapeutic options and for the direct comparison of established AADs.

Multi-Modality Imaging for Prevention of Coronary Artery Disease and Myocardial Infarction in the General Population: Ready for Prime Time?

Cardiovascular disease (CVD) remains a leading cause of death and disability worldwide. Acute myocardial infarction (AMI) causes irreversible myocardial damage, heart failure, life-threatening arrythmias and sudden cardiac death (SCD), and is a main driver of CVD mortality and morbidity. To control the forecasted increase in CVD burden for both the individual and society, improved strategies for the prevention of AMI and SCD are required. Current prevention of AMI and SCD is directed towards risk-modifying interventions, guided by risk assessment using clinical risk prediction scores (CRPSs) and the coronary artery calcium score (CACS). Early detection of more advanced coronary artery disease (CAD), beyond risk assessment by CRPSs or CACS, is a promising strategy to allow personalized treatment for the improved prevention of AMI and SCD in the general population. We review evidence for further testing, beyond CRPSs and CACS, and therapies focusing on promising targets, including subclinical obstructive CAD, high-risk plaques, and silent myocardial ischemia. We also evaluate the potential of multi-modality imaging to enhance the conduction of adequately powered trials to provide high-quality evidence on the impact of add-on tests and therapies in the prevention of AMI and SCD in asymptomatic individuals. To conclude, we discuss the occurrence of AMI and SCD in individuals currently estimated to be at “low-risk” by the current strategy based on CRPSs, and methods to improve prevention of AMI and SCD in this “low-risk” population.

Multimodal deep learning enhances diagnostic precision in left ventricular hypertrophy.

Determining the aetiology of left ventricular hypertrophy (LVH) can be challenging due to the similarity in clinical presentation and cardiac morphological features of diverse causes of disease. In particular, distinguishing individuals with hypertrophic cardiomyopathy (HCM) from the much larger set of individuals with manifest or occult hypertension (HTN) is of major importance for family screening and the prevention of sudden death. We hypothesized that an artificial intelligence method based joint interpretation of 12-lead electrocardiograms and echocardiogram videos could augment physician interpretation. We chose not to train on proximate data labels such as physician over-reads of ECGs or echocardiograms but instead took advantage of electronic health record derived clinical blood pressure measurements and diagnostic consensus (often including molecular testing) among physicians in an HCM centre of excellence. Using more than 18 000 combined instances of electrocardiograms and echocardiograms from 2728 patients, we developed LVH-fusion. On held-out test data, LVH-fusion achieved an F1-score of 0.71 in predicting HCM, and 0.96 in predicting HTN. In head-to-head comparison with human readers LVH-fusion had higher sensitivity and specificity rates than its human counterparts. Finally, we use explainability techniques to investigate local and global features that positively and negatively impact LVH-fusion prediction estimates providing confirmation from unsupervised analysis the diagnostic power of lateral T-wave inversion on the ECG and proximal septal hypertrophy on the echocardiogram for HCM. These results show that deep learning can provide effective physician augmentation in the face of a common diagnostic dilemma with far reaching implications for the prevention of sudden cardiac death.

Predictors of primary prevention implantable cardioverter-defibrillator use in heart failure with reduced ejection fraction: impact of the predicted risk of sudden cardiac death and all-cause mortality.

AimsUse of implantable cardioverter‐defibrillators (ICD) for primary prevention of sudden cardiac death (SCD) in heart failure with reduced ejection fraction (HFrEF) is limited. We aimed to investigate barriers to ICD use in HFrEF while considering the predicted risk of mortality and SCD.Method and resultsPatients from the SwedeHF registered in 2011–2018 and with an indication for primary prevention ICD were analysed. The Seattle Proportional Risk and Seattle Heart Failure Models were used to predict the proportional SCD and all‐cause mortality risk, respectively. A multivariable logistic regression model was fitted to identify independent predictors of ICD use/non‐use; Cox regression models to evaluate the interaction between predicted SCD/mortality risk and ICD use for mortality. Of 13 475 patients, only 15.5% had an ICD. Those with higher predicted proportional SCD risk (>45%) had an ∼80% higher likelihood to have an ICD. Other predictors of non‐use were follow‐up in primary versus specialty care, higher comorbidity burden and lower socioeconomic status. ICD use was associated with lower mortality only in patients with higher predicted SCD and lower mortality risk (34% and 37% relative risk reduction for 3‐year all‐cause and cardiovascular mortality, respectively). In this subgroup of patients, underuse of ICD was 81.8%.ConclusionIn a contemporary registry, only 15.5% of patients with an indication for primary prevention ICD received the device. While a high predicted proportional SCD risk was appropriately linked to ICD use, the lack of specialized follow‐up, higher comorbidity burden, and lower socioeconomic status were major unjustified impediments to implementation. Our findings suggest areas for improving ICD use for primary prevention of SCD in clinical practice.

Feasibility, efficacy and safety of subcutaneous implantable cardioverter defibrillator in patients with a previous median sternotomy

Abstract Funding Acknowledgements Type of funding sources: None. Background Subcutaneous implantable cardioverter defibrillator (S-ICD) has been shown to be an effective therapy for prevention of sudden cardiac death (SCD) with improved outcomes and fewer lead-related complications compared to transvenous cardioverter defibrillator (TV-ICD). Patients who previously underwent cardiac surgery with median sternotomy (MS) may be at risk of SCD and require ICD implantation. However, there are no data on the performance of the S-ICD in this patient cohort. Purpose To assess feasibility, periprocedural and long-term complications associated with implantation of S-ICD in patients with a previous MS. Methods All 128 patients who received a S-ICD at our Centre were enrolled in the study. Baseline and procedural characteristics and complications were collected and retrospectively analyzed. Long-term outcomes were considered as appropriate and inappropriate shocks (IAS), and complications during follow-up. To estimate arrhythmia-free survival, Kaplan–Meier curves were constructed. Cox regression was performed to analyze multivariate predictors of recurrences. Results Among 128 patients (79.7% male sex; mean age 50±15 years), 18 of them had a previous MS. Coronary artery disease was present in 26.6% of the total population, while not ischemic aetiology was present in the 75.4% of them; among this cohort, the most prevalent pathology was hypertrophic cardiomyopathy (21.9%). Primary prevention cohort was the 61.1% in the MS group and the 77.3% in the no MS group. S-ICD implant was successful in 100% of cases. No periprocedural complications were registered. After a median follow up of 3.9 years, no one of the 101 patients had sternal complications. There were no differences in delivery of appropriate shocks (12.5% in MS group vs 7.69% in no MS group, p=0.583) neither in delivery of IAS (6.25% in MS group vs 9.89% in no MS group, p=0.594). At the univariate analysis on IAS there were no differences between the group with or without MS (10% vs 16.38%, p=0.594), but there were significative differences between patients with or without arrhythmogenic right ventricular dysplasia (ARVC; 20% vs 2%, p=0.006), between patients with or without diabetes (30% vs 9.89%, p=0.03), between patients with or without chronic obstructive pulmonary disease (30% vs 4.39%, p=0.002) and between patients who used to smoke and patient who did not (40% vs 16.48%, p=0.03). At multivariate analysis, advanced age (hazard ratio 1.033; 95% CI, 1.014 to 1.053; p=0.001) and ARVC (hazard ratio 5.133; 95% CI, 1.515 to 17.399; p=0.009) were significantly associated with delivery of IAS. Conclusion Implanting a S-ICD is feasible, safe and effective as in patients without a previous MS; in patients who underwent a S-ICD, a previous MS is not associated with a major risk of sternal complications or delivery of IAS; advanced age and ARVC are independently associated with a major risk of delivery of IAS.

Should we implant cardioverter defibrillators in asymptomatic patients with Brugada syndrome?

Abstract Funding Acknowledgements Type of funding sources: None. Background Implantable cardiverter defibrillators (ICD) represent the only effective treatment in prevention of sudden cardiac death (SCD) in patients with Brugada syndrome (BrS). However, according to current ESC Guidelines, ICD implantation is recommended only in secondary prevention, while it should be considered in patients with a spontaneous diagnostic type I ECG pattern and history of syncope. Purpose We aimed to determine the frequency of ventricular tachyarrhythmias during the long-term follow-up among patients with BrS and ICDs implanted in primary or secondary prevention. Methods This retrospective, observational study was conducted in a tertiary center among adult patients with BrS that underwent single or dual chamber ICD implantation from January 2008 to December 2017. The study group was devided into subgroups depending on weather the patients at the time of ICD implantation had documented sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) regardless of the ECG type of BrS (group I), had BrS type I and history of syncope (group II) or had BrS type I and were asymptomatic but assessed as in high risk of SCD due to non-sustained VT episodes, younger age or history of SCD in close family members (group III). We used patients medical records for collecting the data about VT and VF episodes during the follow-up period. Results In the course of ten-year period, ICDs were implanted in 21 adult patients with BrS (66.7% were male). Mean age at the ICD implantation time was 40.3 ± 14.9 years. We analyzed 8 patients from group I, 7 patients from group II, and 6 patients from group III. Mean follow-up period was 82.5 ± 33.3 months. During the obsereved period, VT/VF episodes were appropriately detected in 7 patients from group I (87.5%), in 3 patients from group II (42.86%) and in one patient from group III (16.67%). Kruskal-Wallis test showed that there was a statistically significant difference in the occurrence of ventricular tachyarrhythmias among at least one pair of observed groups (p = 0.031). Using Dunn-Bonferroni post hoc analysis we found statistically significant difference between the patients with malignant arrhythmias and asymptomatic patients (p = 0.03), but not between the other pairs. Conclusion Although asymptomatic patients with BrS are at significantly lower risk of SCD, it is important to identify high-risk patients in the low-risk group. Therefore, creating a tool for calculating the risk of SCD among these patients might be helpfull in everyday clinical practice.