Search clinical trials by condition, location and status
Sudden cardiac death (SCD) poses a significant health care challenge with high annual incidence and low survival rates. Implantable cardioverter defibrillators (ICDs) prevent SCD in patients with poor heart function. However, the critical survival benefit afforded by the devices is accompanied by short and long-term complications and a high economic burden. Moreover, in using current practice guidelines of reduced heart function, specifically left ventricular ejection fraction (LVEF)≤35%, as the main determining factor for patient selection, only a minority of patients actually benefit from ICD therapy (\<25% in 5 years). There is an essential need for more robust diagnostic approaches to SCD risk stratification. This project examines the hypothesis that structural abnormalities of the heart itself, above and beyond global LV dysfunction, are important predictors of SCD risk since they indicate the presence of the abnormal tissue substrate required for the abnormal electrical circuits and heart rhythms that actually lead to SCD. Information about the heart's structure will be obtained from cardiac magnetic resonance imaging and used in combination with a number of other clinical risk factors to see if certain characteristics can better predict patients at risk for SCD.
The overall hypothesis of this study is that subtle interactions between structural (substrate) and functional (trigger) abnormalities of the heart, some of which are genetically-determined, can be used to identify patients at high risk of sudden cardiac death (SCD). Such information may be used to better define patients most likely to benefit from replacement of an internal defibrillator (ICD). The prospective, observational study to enroll, categorize and follow patients who receive an ICD pulse generator replacement for primary prevention of SCD (PROSe-ICD) was established to : 1. to gain a better understanding of the biological mechanisms that predispose to SCD 2. to develop readily determined clinical, electrocardiographic, genetic and blood protein markers identify patients with an increased risk of dying suddenly
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.
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.
The purpose of this research study is to examine the effect of cardiac sympathetic denervation (CSD) surgery on life threatening abnormal heart rhythms called ventricular tachycardia or ventricular fibrillation that can lead to sudden cardiac death. Subjects will be asked to participate in this research study if they have recurrent ventricular tachycardia (at least one ICD shock for ventricular tachycardia) and have undergone at least one catheter ablation procedure or have ventricular tachycardia or fibrillation that is not ablatable. The goal of this study is to determine whether cardiac sympathetic denervation can prevent these abnormal heart rhythms from occurring and therefore, prevent, ICD shocks which are not only painful, but have been shown to reduce quality of life and/or lead to depression, particularly in the period immediately after the shock.
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.
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.
Individuals with repaired Tetralogy of Fallot (rTOF) remain at risk for sudden cardiac death from ventricular tachycardia (VT). Transcatheter pulmonary valve replacement (TPVR) indications continue to broaden, yet its capability to reduce the risk of VT and sudden cardiac death remains unknown. Thus, in a cohort of participants with rTOF who are presenting for TPVR the investigators intend to: (1) quantify and localize right ventricular (RV) isthmuses with abnormal voltage and/or conduction velocity; (2) identify which RV isthmuses are at risk of being "jailed" by TPV prostheses; and (3) explore the feasibility of omnipolar technology to characterize wavefront directionality and differentiate slow conduction from conduction block.
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
Advanced heart failure, affecting 7 million Americans, has multiple causes and results in greatly increased risk of disability and death. A major problem is sudden cardiac death, when the damaged heart develops an abnormal pattern of electrical conduction that can result in cessation of heart activity. While placement of an Implantable Cardioverter-Defibrillator (ICD) in a patient's chest can help prevent sudden cardiac death, these devices have several important downsides. This protocol focuses on development of a digital decision aid that helps heart failure patients make informed decisions that balance the benefits and downsides of ICD placement. This protocol covers the use of participant surveys, focus groups, and interviews to obtain the needed background information to guide the development of this digital tool, which will be subsequently tested against usual care in a randomized clinical trial. The study design is best described as a mixed methods evaluation and refinement of a digital app to improve ICD decision-making. In the future, the present protocol will be modified to create a new protocol that covers the needed human subjects requirements for performance of this clinical trial.