Active clinical trials for "Atrial Fibrillation"

Atrial fibrillation (AF) is the most common sustained heart rhythm abnormality. Its incidence is increasing partly due to the ageing population and it has been referred to as a growing epidemic. AF results in irregular contractions of the heart causing unpleasant symptoms of palpitations and increasing the risk of stroke, heart failure and death. Percutaneous catheter ablation is a safe treatment option in symptomatic patients with AF. The success rate of these procedures have improved with time due to our better understanding of AF, development of new techniques and technology, and greater physician experience. However, the success rate of these procedures still only remains around 70%. This is contributed to our limited ability to find the areas that drive the AF. STAR mapping is a novel mapping system that has been developed with a view of better identifying the sites that drive AF, through taking into account the mechanisms of AF that have already been demonstrated. Data from this study will be used to refine the identification of drivers in the fibrillation left atrium with enormous potential to simplify ablation and improve success rates and thereby reducing the need for further procedures. To better validate this mapping system the investigators also aim to use it in participants with atrial tachycardia (AT), which is a heart rhythm abnormality of which the mechanism can be readily identified with the existing mapping systems used in clinical practice. The investigators will demonstrate that the STAR mapping algorithm can effectively map AT. To gain further understanding of the changes that occur in the left upper chamber of the heart in the context of AF half of the participants with AF will undergo cardiac magnetic resonance imaging to assess for the presence of scar. This will enhance our understanding of how atrial remodelling promotes AF, which may point to ways of modifying this process and preventing AF.

Atrial fibrillation is the most common heart rhythm disorder. For patients suffering atrial fibrillation direct current cardioversion is performed to reduce patients symptoms and prevent disease progression. The optimal energy selection for biphasic cardioversion is unknown. We aim to investigate the efficiency and safety of a high energy shock protocol (360 J) versus a standard escalating shock protocol (125-150-200 J) in cardioversion of atrial fibrillation.

Title: CLOSE-guided pulmonary vein isolation (PVI) as Cure for Paroxysmal Atrial Fibrillation ('CLOSE to CURE' study) Design: This is a prospective, observational, single-center, unblinded, clinical 3-year study. Background: In a population of paroxysmal atrial fibrillation (AF) 'CLOSE'-guided PVI, a new approach to obtain single-procedure durable PVI, has been shown to virtually eliminate recurrence of AF at 1 year follow-up with repetitive but discontinuous Holter monitoring. Objectives: (1) To objectively compare atrial tachyarrhythmia (ATA) burden before and after 'CLOSE'-guided based PVI using continuous monitoring. (2) To assess ATA burden using continuous monitoring up to 3 years after ablation. (3) To identify baseline structural and electrical properties of the atria or procedural characteristics that predict 1-year and 3-year outcome. Enrollment: Up to 100 subjects will be enrolled in this observational, prospective study. Clinical Sites: 1 site. Subject Population: Eligible patients are patients with paroxysmal high-burden AF who are planned for a 'CLOSE'-guided PV isolation. At the time of procedural planning we will ask the patient his/her consent for (1) implantation of a subcutaneous continuous loop recorder (sCLR), (2) a concise electrophysiological study at the time of PVI, (3) a transthoracic echocardiogram at the time of PVI and (4) collection of data during 3 years. Anti-arrhythmic drug treatment (ADT) and oral anticoagulation (OAC) will be given according the updated 2012 European society of Cardiology (ESC) guidelines on AF (Camm et al, European Heart Journal 2012) and the 2012 Heart rhythm society (HRS)/European Heart Rhythm association/European cardiac arrhythmic society Expert Consensus Statement on catheter and surgical ablation of atrial fibrillation (Calkins et al, Heart Rhythm 2012).

The purpose of this study is to evaluate real-time gap detection using EPD D700 dielectric sensing compared with customary electrical isolation tests and Adenosine infusion at the end of the procedure. Furthermore, safety, usability and clinical applicability of the system for guided AF ablation will be confirmed.

The aim of our study is to investigate the comparative efficacy of high fidelity multi electrode ablation catheters vs the standard bipolar configuration in success of AV nodal ablation This study will provide insights on the use of new technology where application may increase efficacy, promote patient and physician safety and decrease costs.

The COR advance study is a non-randomized prospective single center study to assess the results of an electrophysiologically guided approach for PV cryoablation using the Arctic Front Advance ST® catheter together with the Achieve® mapping catheter in 25 patients with drug-refractory paroxysmal AF. Methods Patient selection criteria will be the same that in the original COR study. All patients will be followed with a Reveal LINQ® cardiac monitor that will be implanted before ablation. The primary objective is the proportion of patients remaining free from atrial fibrillation recurrences without taking antiarrhythmic drugs 12 months after ablation. Secondary objectives are: AF-free survival without anti arrhythmic drugs 12 months after ablation, cumulative AF burden (number of AF episodes and percentage of time in AF) 12 months after ablation, percentage of the pulmonary veins with bidirectional block at the end of the procedure, and ablation time (from the onset of the first energy delivery to the end of the last energy delivery), procedure time (from femoral puncture to catheter removal), and fluoroscopy time. Final results will be known 24 months after the first enrollment. Statistical analysis Continuous variables that are distributed normally according to the Shapiro-Wilk test will be presented as the mean [standard deviation], and the values will be compared with the t test. Continuous variables that do not follow a normal distribution will be presented as the median [25th to 75th percentile] and will be compared with the Mann-Whitney U test. Categorical variables between two groups with expected values <5 will be compared with the Fisher exact test. Otherwise, categorical variables will be compared with the chi-squared test. The AF-free survival functions will be represented as Kaplan-Meier curves. Data analyses will be done with JMP® (version 9.0.1, SAS Institute Inc., Cary, NC, USA) and Stata® (version 11.0, StataCorp LP; College Station, TX, USA).

The purpose of this study is to assess whether the switch from branded to generic warfarin or between different generic warfarin tablets may cause fluctuation in the results of coagulation tests (International Normalized Rate, acronym INR) in patients, thus predisposing them to unnecessary risks.

Purpose: Warfarin is now the most commonly used oral anticoagulant. This drug has inter-individual variability due to the genetic polymorphisms in the warfarin metabolizing enzyme, CYP2C9 and warfarin target, VKORC1. The investigators' team developed a pharmacogenetic dosing algorithm which can predict patients required warfarin dose, thus could prevent warfarin induced warfarin adverse events. Methods: The investigators recruited patients with indications for warfarin, the genotypes of VKORC1 and CYP2C9 were determined by the hospitals and verified by National Center for Genome Medicine. The investigators then randomized the patients to one of three arms: 1. Warfarin dose predicted by dosing algorithm developed by the International Warfarin pharmacogenetic Consortium (IWPC), 2. Algorithm developed by the Taiwan Warfarin Consortium and 3. Standard of care. The investigators aimed to determine whether using genetic dosing algorithm can lead to more stable dose and safer use of the drug.

Atrial fibrillation remains a major cause of morbidity following cardiac surgery with cardiopulmonary bypass. Many mechanisms have been implicated. Among then, adenosine, a strong endogenous vasodilating agent has been involved in cardiac surgery-induced atrial fibrillation, via A2A receptors modulation. The effects of caffeine on the inducibility of atrial fibrillation are actually well-known, leading then to a significant reduction of atrial fibrillation. Moreover, a recent clinical study has demonstrated that coffee drinking was inversely associated with total and cause-specific mortality. The investigators therefore examined the preventive effects of oral caffeine on valvular surgery with cardiopulmonary bypass-induced atrial fibrillation. The investigators also evaluated prospectively the influence of caffeine on adenosine plasma levels and A2A adenosine receptors modulation.

This is a prospective, non-randomized, study of the safety and efficacy of the Occlutech® LAA occluder indicated for percutaneous LAA closure in adult male or female patients with atrial fibrillation. Safety and efficacy will be assessed at day 1, 30 and 90, and after 1 year following implantation of an Occlutech® LAA Occluder.