Sudden Cardiac Death

Background: Bruton s tyrosine kinase inhibitors (BTKi) are used to treat a form of leukemia. But taking BTKi can also increase a person s risk of developing an abnormal heart rhythm. This can cause sudden death. In this natural history study, researchers want to learn how BTKi affects the heart. Objective: To identify and monitor the effects of BTKi on the heart. Eligibility: People aged 18 and older currently receiving or planning to receive BTKi or venetoclax. Design: Participants who have not yet started BTKi will have 2 required clinic visits: 1 before they start taking BTKi, and 1 about 6 months later. Participants who are already taking BTKi will have 1 required visit. Participants will undergo multiple tests: A physical exam, including collection of blood and saliva. A test that measures heart activity via stickers placed on the chest. A test that uses sound waves to capture images of the heart. An exercise stress test that monitors heart activity and blood pressure while the participant works on a treadmill or stationary bike. Sound wave images of the heart may also be taken while the participant exercises. Stress magnetic resonance imaging (MRI) may be done in place of an exercise test. Participants will lie on a table that slides into a tube. They will be given drugs to stress the heart while images are taken. Participants may wear a device to monitor their heart at home. Participants may have repeat visits if they develop heart symptoms or if they need to stop taking BTKi. They will have follow-up phone calls each year for up to 3 years.

The purpose of this study is to determine whether ICD(Implantable Cardioverter Defibrillator) implantation on the top of optimal medical therapy in patients with variant angina manifesting as aborted sudden cardiac death reduces the incidence of the death from any cause compared with optimal medical therapy alone.

The goal of this observational study is to develop a registry of Brazilian patients with hereditary cardiovascular diseases, combining clinical and genomic data. The main questions it aims to answer are: Which genes are most commonly affected? What is the frequency of these genetic alterations in our population? Participants will be interviewed in routine medical care visits and their DNA will be sequenced.

Arrhythmogenic ventricular cardiomyopathy (AVC) is a genetic condition which affects the heart and can lead to heart failure and rhythm problems, of which, sudden cardiac arrest or death is the most tragic and dangerous. Diagnosis and screening of blood-relatives is very difficult as the disease process can be subtle, but sufficient enough, so that the first event is sudden death. The Mayo Clinic AVC Registry is a collaboration between Mayo Clinic, Rochester, USA and Papworth Hospital, Cambridge University Hospitals, Cambridge, UK. The investigators aim to enroll patients with a history of AVC or sudden cardiac death which may be due to AVC, from the US and UK. Family members who are blood-relatives will also be invited, including those who do not have the condition. Data collected include symptoms, ECG, echocardiographic, MRI, Holter, loop recorder, biopsies, exercise stress testing, blood, buccal and saliva samples. Objectives of the study: 1. Discover new genes or altered genes (variants) which cause AVC 2. Identify biomarkers which predict (2a) disease onset, (2b) disease progression, (2c) and the likelihood of arrhythmia (ventricular, supra-ventricular and atrial fibrillation) 3. Correlate genotype with phenotype in confirmed cases of AVC followed longitudinally using clinical, electrocardiographic and imaging data. 4. Characterize desmosomal changes in buccal mucosal cells with genotype and validate with gold-standard endomyocardial biopsies

Anomalous aortic origin of the coronary arteries (AAOCA) is a rare congenital disease and one of the leading causes of sudden cardiac deaths (SCD) in young athletes but also has a lethal presentation in adult age with myocardial infarction, even if not related to obstructive coronary arteries. Unfortunately, diagnostic imaging techniques, invasive assessment, and provocative stress tests have shown low sensitivity and specificity in detecting inducible ischemia, and a multimodality assessment is then necessary. Innovative tools have been developed in the medical field using computer-based simulation, 3-dimensional reconstruction, machine learning, and artificial intelligence (AI). With the application of such new technologies, we aim to fill the gap of knowledge and the diagnostic limitation regarding risk stratification for most subjects with AAOCA. This work seeks to enhance, fasten, and personalize the clinical diagnosis of AAOCA by integrating anatomical measurements, clinical data, and biomechanical patient-specific features. The SMART study will set a system to automatically segment and classify coronary arteries with AAOCA from computerized tomography angiography (CTA) by artificial intelligence (AI). Segmentation will feed a 3D model of the aortic root and coronary artery for biomechanical assessment through finite element analysis (FEA). This will allow us to assess the location of possible coronary artery compression under an effort condition. These in-silico results, the anatomical features measured by AI, and the clinical data will be integrated into a risk model to estimate the hazard risk of adverse events such as SCD or myocardial infarction. This workflow will be framed in an IT system to allow a web-based remote diagnostic service. Thanks to the proposed multidisciplinary approach, SMART aims to overcome the current diagnostic limitations related to the reduced ability of functional stress tests to detect ischemia. Potentially helping in patient-specific risk stratification, SMART is also thought to provide a way to get a first diagnostic indication about AAOCA being accessible from any hospital, fostering the diffusion of peripheral territorial support to the diagnosis and treatment of such rare disease.

TWIN-SCD STEMI is a multicentric prospective, non-randomized pilot study designed to establish a multiparametric model for predicting life-threatening ventricular arrhythmias in patients experiencing their first myocardial infarction. The primary objective of the study is to develop an algorithm with superior predictive performance (sensitivity and specificity) compared to the currently used criterion for the implantation of a cardiac defibrillator, which is a left ventricular ejection fraction (LVEF) of less than 35%.

Acute coronary syndrome (ACS) is one of the main causes of death. Worldwide, tens of millions of patients are hospitalized for coronary heart disease and ACS every year. ACS may show acute myocardial infarction, unstable angina pectoris, and even induce early arrhythmia, leading to sudden death. Sudden cardiac death (SCD) has a strong correlation with ACS. Data from clinical and autopsy studies and death certificates show that 62-85% of patients with out of hospital SCD have a history of ACS, 10% have other cardiac structural abnormalities, and 5% have no cardiac structural abnormalities. An SCD surveillance study from Ireland concluded that most cases occurred in families, and the successful recovery of SCD was mainly related to ventricular fibrillation with arrhythmia. At present, there are few reports on the clinical and prognosis of ACS in China, and there is no guideline or consensus on the prevention and treatment of ACS patients. Known domestic research results show that the proportion of male, overweight / obese, smokers in young ACS patients is higher than that in the elderly group, while the proportion of patients with hypertension, diabetes and cerebrovascular diseases is less than that of the elderly group. The levels of TC, TG, LDL-C and UA and the proportion of low HDL-C in young ACS patients were higher than those in elderly patients; The diagnosis of STEMI was the highest in the young ACS group, while the diagnosis of unstable angina pectoris was the most common in the elderly ACS group. The clinical manifestations of ACS vary greatly. 3% \~ 5% of patients who exclude ACS only through myocardial markers, clinical blood transfusion and ECG still have myocardial infarction (MI). For the emergency department, early prediction of the risk of SCD in ACS patients and timely and accurate screening of high-risk patients are very important.

Patients who have survived a myocardial infarction (MI) are at increased risk for sudden cardiac death (SCD) caused by ventricular tachycardia and ventricular fibrillation. A severely reduced left ventricular ejection fraction (LVEF) as a rough overall measure of impaired heart function after MI was shown to indicate a higher risk for SCD. Based on this observation, two landmark randomised trials, MADIT II and SCD-HeFT, were conducted between end of the 1990s and early 2000s. These trials compared the survival of patients with severely reduced LVEF who received an implantable cardioverter-defibrillator with the survival of patients being on medical therapy alone. They reported a significantly better survival of patients in the defibrillator arm and led to international guideline recommendations for routine implantation of defibrillators in survivors of MI with severely impaired LVEF as a means for primary prevention of SCD. Since then, the management of these patients has changed dramatically with the advent of a series of novel drug classes that reduce not only mortality but specifically SCD leading to a substantial decrease of the sudden death rates as well as of the rates of appropriate defibrillator therapies implanted for primary prevention of SCD. At the same time, the complication rates associated with the defibrilllator therapy remain significant without obvious decrease. Thus, the risk-benefit of routine defibrillator implantation for primary prevention of SCD in patients with severely reduced LVEF has substantially changed since the conduction of the landmark trials that established this therapy. Due to the inherent risks and considerable costs of the defibrillator, a novel randomised adequately powered assessment of the potential benefit or harm of the defibrillator in survivors of MI with reduced LVEF under contemporary optimal medical treatment (OMT) appears imperative. OBJECTIVE: To demonstrate that in post-MI patients with symptomatic heart failure who receive OMT for this condition, and with reduced LVEF ≤ 35%, OMT without ICD implantation (index group) is not inferior to OMT with ICD implantation (control group) with respect to all-cause mortality.

WILLEM is a multi-center, prospective and retrospective cohort study. The study will assess the performance of a cloud-based and AI-powered ECG analysis platform, named Willem™, developed to detect arrhythmias and other abnormal cardiac patterns. The main questions it aims to answer are: 1. A new AI-powered ECG analysis platform can automatice the classification and prediction of cardiac arrhythmic episodes at a cardiologist level. 2. This AI-powered ECG analysis can delay or even avoid harmful therapies and severe cardiac adverse events such as sudden death. The prerequisites for inclusion of patients will be the availability of at least one ECG record in raw data, along with patient clinical data and evolution data after more than 1-year follow-up. Cardiac electrical signals from multiple medical devices will be collected by cardiology experts after obtaining the informed consent. Every cardiac electrical signal from every subject will be reviewed by a board-certified cardiologist to label the arrhythmias and patterns recorded in those tracings. In order to obtain tracings of relevant information, \>95% of the subjects enrolled will have rhythm disorders or abnormal ECG's patterns at the time of enrollment.

This study is designed as a prospective, single-center, observational cohort study (the SMART-SCD Study, full name: Skeletal Muscle Multi-omics Analysis and Risk Tailoring in Sudden Cardiac Death), which enrolls high-risk populations meeting the criteria for implantable cardioverter defibrillator (ICD) implantation. The research focuses on the mechanistic association between skeletal muscle metabolic disorders and ventricular arrhythmia (VA) as well as sudden cardiac death (SCD), and aims to construct a "muscle-heart crosstalk" risk early warning system through integration of multimodal skeletal muscle data. We will systematically collect the following data: Baseline handgrip strength measurement (Biomi-h500+X5); Functional diagnosis and phenotyping of sarcopenia conducted via the InBody 270 body composition analyzer; Non-contrast chest and abdominal computed tomography (CT) images (to extract novel imaging phenotypes including skeletal muscle density at the T12 vertebra level, intermuscular adipose tissue, subcutaneous adipose tissue, etc.); Serum biomarkers (GDF-8, Irisin, IL-6); Metabolomics data of skeletal muscle tissue from the ICD pocket (lipid/energy metabolism profiles detected via the UPLC-QTOF/MS platform); Ambulatory electrocardiographic data. All treatment and intervention regimens for patients will be independently formulated by clinicians in accordance with clinical guidelines, and the study itself does not involve any intervention measures. Prospective follow-up will be conducted at 3/6/12 months after ICD implantation. The primary endpoint is composite ventricular arrhythmia events (including SCD, appropriate ICD therapy documented by the device, and hemodynamically unstable ventricular tachycardia/ventricular fibrillation), and the secondary endpoint is all-cause mortality. Through the above prospective cohort study, we will integrate multimodal data including novel CT imaging phenotypes of skeletal muscle, metabolomics profiles and functional phenotyping of sarcopenia using artificial intelligence techniques, so as to construct a precision prediction model for SCD, screen novel CT imaging phenotypes of sarcopenia and myogenic metabolites, and finally establish a generalizable SCD risk assessment tool and individualized intervention strategies.

Long-term sudden cardiac death (abbreviation: SCAR) focuses on improving the predictability of sudden cardiac death (SCD) in patients diagnosed with coronary artery disease. The aim of the study is to determine the predictive value of measurable biological variables (including genetic factors, cardiac electrical activity, biological markers measured from circulation, and coronary artery anatomy) as well as the patients' psychosocial factors in predicting SCDs. The purpose of this study is the identification of a subgroup of coronary artery disease patients at sufficiently high risk in whom it may be possible to prevent sudden cardiac arrests and subsequent deaths using implantable cardioverter-defibrillators. The study is intended to establish a clear foundation for future interventional studies targeting high-risk coronary artery disease patients. The primary endpoint of the study is SCD/sudden cardiac arrest (SCA) or a comparable malignant arrhythmic event (i.e., resuscitation). Secondary endpoints include other major cardiovascular events occurring during the follow-up period (such as cerebrovascular events, myocardial infarctions, revascularizations, and new arrhythmias like atrial fibrillation following procedures or after the patient has been discharged following recruitment) or the occurrence and mortality of other significant life-threatening diseases (such as cancer). Secondary endpoints also include poor success in secondary prevention, which can be assessed through completed medication purchases and the achievement of secondary prevention goals. This observational, prospective study includes collecting multimodal data from hospitals in Finland (TAUH), Israel (HYMC), Moldova (IMSP) and Romania (UMFCD). Each participating institution has followed a process structured by Tampere Heart Hospital (TAUH) for securing permissions in line with EU and national regulations.

Research questions: The value of primary prevention implantable cardioverter-defibrillator implantation (ICD) therapy in patients with non-ischemic cardiomyopathy (NICM) is under debate. Improved risk stratification is needed to select patients at highest risk. Hypotheses: 1. In NICM patients with CMR detected myocardial fibrosis, ICD implantation reduces all-cause mortality compared to guideline-directed medical therapy (GDMT) only. 2. Myocardial fibrosis assessed by cardiac MRI (CMR) can be used to stratify patients according to risk for sudden cardiac death. Study design: 1. Patients with myocardial fibrosis: Randomized controlled trial (RCT). 2. Patients without myocardial fibrosis: Prospective registry. Study population: Patients with non-ischemic cardiomyopathy with LVEF \<35% after at least 3 months of guideline-directed medical therapy (GDMT). Intervention: ICD implantation. Main study parameters/endpoints: primary endpoint: all-cause mortality. Secondary endpoints include: patient clinical status, quality of life, sudden cardiac death, ventricular arrhythmias, ICD complications and ICD therapy Nature and extent of the burden and risks associated with participation, benefit and group relatedness: All ICDs that are implanted in the study are standard devices that are used in daily clinical practice. Patients who are randomized to ICD implantation will be subjected to the risk of perioperative and long-term complications but will be partly protected against death from ventricular arrhythmias. Patients randomized to no ICD implantation will not be protected against the residual risk of sudden cardiac death but are not subjected to complications from ICD implantation and possible subsequent complications. The only additional burden for patients is completing quality-of-life questionnaires, all hospital visits are for routine follow-up.

Pilot interventional randomized clinical trial to study the efficacy of left bundle branch pacing in patients with hypertrophic cardiomyopathy after myectomy for the prevention of progression of heart failure, prevent the occurrence of life-threatening rhythm disturbances and promote reverse remodeling of the LV. The aim of the study is to evaluate the comparative efficacy and safety of implantation of a cardioverter-defibrillator with left bundle branch block pacing and a dual-chamber cardioverter-defibrillator in patients with HCM and complete left bundle branch block after myectomy at high risk of SCD. Objectives of the study: 1. To analyze the safety of ICD implantation procedures with LBBB pacing in patients with HCM and LBBB after myectomy at high risk of SCD; 2. To develop a technique for LBBB lead implantation in patients with HCM and LBBB after myectomy; 3. To conduct a comparative analysis of QRS complex duration data based on ECG data before and after surgery, LV activation time, and pacing threshold based on postoperative programming data; 4. To conduct a comparative analysis of the functional class of CHF, NT-proBNP, the presence/absence of interventricular and intraventricular dyssynchrony, the degree of diastolic dysfunction, LVEF, and LV EDV based on echocardiography data before and 12 months after surgery; 5. Conduct a comparative analysis of QRS complex duration data based on ECG data, LV activation time, pacing threshold, the presence of recorded episodes of AF, VT, VF, antitachycardia and shock therapy according to programming data at 3, 6, and 12 months after surgery; 6. Assess quality of life before and 12 months after surgery using the KCCQ-12 questionnaire; 30 patients (15 patients in each group) will be randomly separated into 2 groups. All participants go through ICD programming at 3, 6, and 12 months after myectomy, assessment of left ventricular remodeling based on ECG and echocardiography, NT-proBNP, assessment of quality of life before surgery and 12 months after surgery.

Sudden cardiac death is a tragic event that strikes all age groups and is unfortunately increasing in prevalence. Because it is difficult to predict those at highest risk, this study is designed to test the hypothesis that new imaging techniques (magnetic resonance imaging \[MRI\] and computed tomography \[CT\]) are useful for identifying factors which put people at high risk for sudden death.

This prospective, multicenter, open-label, randomized comparative effectiveness trial, titled CARVTOP-ICD, evaluates the impact of carvedilol versus metoprolol succinate in patients with heart failure with reduced ejection fraction (HFrEF) and an implantable cardioverter defibrillator (ICD). The study will enroll 2,000 participants across 100 U.S. sites and includes an 18-month feasibility phase with 100 participants from 15 sites. Eligible participants must be currently treated with metoprolol succinate and willing to switch to carvedilol, with randomization in a 1:1 ratio. Participants will be followed for up to 3 years, with regular assessments including ICD interrogations, medication adherence, healthcare utilization, and quality of life surveys. The primary endpoint is the first occurrence of any ICD therapy (appropriate or inappropriate), cardiovascular (CV) hospitalization, or CV death. Secondary endpoints include ICD shock burden, healthcare utilization, and patient-reported quality of life. The trial aims to provide high-quality comparative data to address clinical equipoise surrounding the two commonly used beta-blockers in HFrEF management.

This trial investigates two key aspects of the S-ICD implantation process. 1) For S-ICD implantation a pre-operative x-ray-based assessment of the anatomy and location of the heart is required. This study seeks to investigate the feasibility of US to potentially replace the need for x-ray 2) The PRAETORIAN score predicts defibrillation test success in subcutaneous ICD implantation but can only be calculated after the procedure. This pilot study aims to evaluate the feasibility of US determining the PRAETORIAN score intraoperatively. Lead-to-sternum distance and generator position measurments during the implantation procedure will be evaluated. Twenty consecutive patients scheduled for S-ICD implantation will be enrolled. The study involves no deviation from standard implantation procedures and requires no follow-up beyond standard post-operative chest X-ray on day one.

The incidence of stroke-heart syndrome following acute stroke, which encompasses both acute ischemic stroke and acute intracerebral hemorrhage, is notably high and is strongly associated with increased mortality and poor outcomes in stroke patients. However, the underlying mechanisms remain unclear, and there are currently no effective prevention or treatment strategies. This study aims to elucidate the neuro-humoral mechanisms of stroke-heart syndrome through multimodal imaging and multi-omics blood analysis. Additionally, it seeks to observe the progression of stroke-heart syndrome and its impact on functional outcomes, cognitive abilities, and emotional issues post-stroke. The research is expected to uncover novel blood biomarkers and brain network mechanisms associated with stroke-heart syndrome, providing potential targets and theoretical foundations for pharmacological treatments or physical interventions. Furthermore, it aims to establish a risk early-warning system for major cardiovascular complications post-stroke, enabling early identification, early intervention, and integrated brain-heart management to improve clinical outcomes for stroke patients.

Myocardial Bridge Bypass Graft surgery is introduced to relieve the unmedical symptoms of patients with long-segment or deep myocardial bridge, clinical outcomes will be collected to verify the effectiveness of the surgery.

The study aims to identify new diagnostic and prognostic markers for CMP that can help predict disease progression. In particular, the study will focus on microRNAs (miRNAs) and spatial transcriptomics, which are emerging techniques that may provide insights into the underlying disease mechanisms. By understanding these markers, the investigators hope to improve the way the investigators diagnose and manage CMP, particularly in terms of predicting progression to heart failure or heart transplantation. The study will evaluate patients with hypertrophic cardiomyopathy (e.g., sarcomeric forms, Anderson-Fabry disease, AL, and TTR cardiac amyloidosis), dilated cardiomyopathy and arrhythmogenic cardiomyopathy. These patients will undergo clinical evaluations, including ECG, echocardiograms, CMR, biopsy analysis, and genetic testing, as well as molecular studies such as transcriptomics and miRNA analysis. This comprehensive approach aims to identify potential new biomarkers for diagnosing and predicting the disease course.

The goal of this observational study is to recognize clinical and genetic risk factors for sudden cardiac arrest (SCA) and death (SCD) in patients with coronary artery disease (CAD). The main questions it aims to answer are: Are we able to recognize clinical or treatment-related risk factors for SCA or SCD? Can we identify new genetic risk factors for SCA or SCD in patients under 75 years? Participants diagnosed with CAD answer a short survey about their medical history and socioeconomic status. A standard ECG addition to a five (5) minute ECG recording is taken from all the study subjects. In addition to a few short physiological tests (e.g. blood pressure, height, weight, grip strength), a blood sample is withdrawn from a selected group of study subjects. Medical healthcare records are used to follow all study subjects, and no follow-up visits are required.

The increased risk of sudden cardiac arrest (SCA) or sudden cardiac death (SCD) related to vigorous physical activity is well-documented. Currently, for young victims (under 35 years) of SCA/SCD, no etiology is found in 40 to 50% of cases after a standard medical assessment, leading to two important consequences. For the victim's family, it is difficult to understand and accept this tragic event, and the risk of it occurring in another family member is a source of concern. Medically, the absence of a known cause limits the ability to effectively prevent such events. The RESOUDRE study will be a national, prospective, observational registry of young victims (12-35 years) of sports-related SCA/SCD. All cases will undergo the recommended etiological assessment, including autopsy for SCA cases, along with whole exome genetic analysis and toxicological testing. In the event a genetic pathology is identified, a genetic evaluation will be offered to other family members, and appropriate medical care will be provided if necessary. The results of this study could significantly reduce the number of unexplained sport-related SCA/SCD cases and aid in preventing these incidents among affected families.

The Multitude is a registry of patients who receive commercially available CIEDs that remotely communicate through the LATITUDE monitoring system and transfer data to a central database. The registry is designed to constitute a shared environment for the collection, management, analysis and reporting of clinical and diagnostic data, adopted by a network of European scientifically-motivated physicians who use rhythm management diagnostic and therapeutic solutions from Boston Scientific in their clinical practice. The Multitude study will facilitate the sharing of scientific proposals within a large network of researchers, and it will allow researchers to record the experience with medical devices throughout the device and patient lifecycle.

The entirely subcutaneous implantable defibrillator (S-ICD) (Emblem, Boston Scientific, Marlborough, MA, USA) was introduced as a new therapeutic alternative to the conventional transvenous ICD in 2009 and implantations are rapidly expanding since then.1 Implantation of the S-ICD seems to reduce implant-related perioperative complications such as pneumothorax, hematoma and cardiac tamponade. The aim of this multicenter registry is thus to assess the outcome of patients following an S-ICD implantation in a real-world setting.

The goal of this observational study is to identify potential indicators for pre-warning of sudden cardiac death (SCD), including clinical biochemistry markers, electrocardiogram, echocardiography, MRI and CT imaging values, genetic markers and so on, and further construct a series of multi-parameter assessments of SCD early screening.

The PROTECT-ICD trial is a physician-led, multi-centre randomised controlled trial targeting prevention of sudden cardiac death in patients who have poor cardiac function following a myocardial infarct (MI). The trial aims to assess the role of electrophysiology study (EPS) in guiding implantable cardioverter-defibrillator (ICD) implantation, in patients early following MI (first 40 days). The secondary aim is to assess the utility of cardiac MRI (CMR) in analysing cardiac function and viability as well as predicting inducible and spontaneous ventricular tachyarrhythmia when performed early post MI. Following a MI patients are at high risk of sudden cardiac death (SCD). The risk is highest in the first 40 days; however, current guidelines exclude patients from receiving an ICD during this time. This limitation is based largely on a single study, The Defibrillator in Acute Myocardial Infarction Trial (DINAMIT), which failed to demonstrate a benefit of early ICD implantation. However, this study was underpowered and used non-invasive tests to identify patients at high risk. EPS identifies patients with the substrate for re-entrant tachyarrhythmia, and has been found in multiple studies to predict patients at risk of SCD. Contrast-enhanced CMR is a non-invasive test without radiation exposure which can be used to assess left ventricular function. In addition, it provides information on myocardial viability, scar size and tissue heterogeneity. It has an emerging role as a predictor of mortality and spontaneous ventricular arrhythmia in patients with a previous MI. A total of 1,058 patients who are at high risk of SCD based on poor cardiac function (left ventricular ejection fraction (LVEF) ≤40%) following a ST-elevation or non-STE myocardial infarct will be enrolled in the trial. Patients will be randomised 1:1 to either the intervention or control arm. In the intervention arm all patients undergo early EPS. Patients with a positive study (inducible ventricular tachycardia cycle length ≥200ms) receive an ICD, while patients with a negative study (inducible ventricular fibrillation or no inducible VT) are discharged without an ICD, regardless of the LVEF. In the control arm patients are treated according to standard local practice. This involves early discharge and repeat assessment of cardiac function after 40 days or after 90 days following revascularisation (PCI or CABG). ICD implantation after 40 days according to current guidelines (LVEF≤30%, or ≤35% with New York Heart Association (NYHA) class II/III symptoms) could be considered, if part of local standard practice, however the ICD is not funded by the trial. A proportion of trial patients from both the intervention and control arms at \>48 hours following MI will undergo CMR to enable correlation with (1) inducible VT at EPS and (2) SCD and non-fatal arrhythmia on follow up. It will be used to simultaneously assess left ventricular function, ventricular strain, myocardial infarction size, and peri-infarction injury. The size of the infarct core, infarct gray zone (as a measure of tissue heterogeneity) and total infarct size will be quantified for each patient. All patients will be followed for 2 years with a combined primary endpoint of non-fatal arrhythmia and SCD. Non-fatal arrhythmia includes resuscitated cardiac arrest, sustained ventricular tachycardia (VT) and ventricular fibrillation (VF) in participants without an ICD. Secondary endpoints will include all-cause mortality, non-sudden cardiovascular death, non-fatal repeat MI, heart failure and inappropriate ICD denial. Secondary endpoints for CMR correlation will include (1) the presence or absence of inducible VT at EP study, and (2) combined endpoint of appropriate ICD activation or SCD at follow up. It is anticipated that the intervention arm will reduce the primary endpoint as a result of prevention of a) early sudden cardiac deaths/cardiac arrest, and b) sudden cardiac death/cardiac arrest in patients with a LVEF of 31-40%. It is expected that the 2-year primary endpoint rate will be reduced from 6.7% in the control arm to 2.8% in the intervention arm with a relative risk reduction (RRR) of 68%. A two-group chi-squared test with a 0.05 two-sided significance level will have 80% power to detect the difference between a Group 1 proportion of 0.028 experiencing the primary endpoint and a Group 2 proportion of 0.067 experiencing the primary endpoint when the sample size in each group is 470. Assuming 1% crossover and 10% loss to follow up the required sample size is 1,058 (n=529 patients per arm). To test the hypothesis that tissue heterogeneity at CMR predicts both inducible and spontaneous ventricular tachyarrhythmias will require a sample size of 400 patients to undergo CMR. It is anticipated that the use of EPS will select a group of patients who will benefit from an ICD soon after a MI. This has the potential to change clinical guidelines and save a large number of lives.