10 Clinical Trials for Various Conditions
The purpose of this study is to determine whether levels of inflammatory markers in circulating blood can correlate with risk for dangerous heart rhythms. Patients with systolic heart failure, which has been shown to increase risk for dangerous heart rhythms, will be enrolled. All subjects will have an implantable cardioverter-defibrillator (ICD) in place, which allows regular evaluation of heart rhythm.
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.
The purpose of this research study is to evaluate the effectiveness of metoprolol, a "beta blocker," in treating patients in the hospital with a cardiac arrest. It will be given intravenously (given into a vein). The subjects who will take part in this study are 18 years of age or older, are experiencing a cardiac arrest in the hospital, and are in a life threatening situation. Patients who develop a cardiac arrest require prompt electrical defibrillation (electrical shocks) to restore the normal beating rhythm of the heart. In patients who do not respond to electrical defibrillation, current standard of care recommends the use of medications which have been shown to be of unknown benefit. Some people recover from a cardiac arrest, but many people do not. We want to learn whether giving metoprolol will improve survival of patients with a cardiac arrest. A total of 100 patients will be enrolled in the study. Patients will receive either the standard of care with the drug epinephrine or the standard of care plus metoprolol.
The purpose of the proposed pilot study is to identify factors which are associated with periods of high ventricular arrhythmia burden. This will be performed by analysis of gene expression from peripheral blood samples.
The investigators have conducted a prospective, double-blind, randomized study to assess the comparative safety and efficacy of two different ablation strategies, RFA versus RFA plus botulinum toxin injection, in patients with supra-ventricular tachyarrhythmias. Results were assessed with the use of an implanted monitoring device (IMD).
This study will test the hypothesis that many human heart rhythm disorders are caused by small localized sources, where brief ablation may successfully eliminate the heart rhythm disorder.
The purpose of this post approval study is to characterize the chronic performance of the SJM Optisure family of HV leads in patients.
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 objective of this trial is to determine the efficacy and safety of adjunctive catheter-based renal sympathetic denervation (RSDN) in the primary prevention of implantable cardioverter defibrillator (ICD) therapy in patients with ischemic or non-ischemic ventricular dysfunction, who are to receive an ICD for either i) secondary prevention, or ii) primary prevention + inducible ventricular tachycardia (VT) by programmed ventricular stimulation at the time of ICD implantation. These patients will be randomized to ICD alone or ICD + RSDN.
The purpose of the study is two-fold. In Phase I (Protecta Clinical Study), system performance will be evaluated. In Phase II (PainFree SST), the inappropriate shock-free rate at one year of subjects implanted with a Medtronic Protecta implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) will be evaluated.