Active clinical trials for "Atrial Fibrillation"

This proposal is aiming at modifying and improving persistent AF management guidelines by evaluating targeting DE-MRI detected atrial fibrosis during AF ablation and its related effect on procedural outcome. OBJECTIVES: Primary Objective: To examine the efficacy of targeting atrial fibrosis tissue during an ablation procedure in treating persistent AF. Results from the DECAAF study show that one of the most important predictors of ablation outcome was the degree of ablation of the fibrotic tissue; the more fibrotic tissue that was overlapped with scar during ablation, the better the outcome. These results were the impetus for the primary outcome of DECAAF II. Patients will be randomized to receive conventional pulmonary vein isolation (PVI) ablation or PVI + fibrosis-guided ablation. The investigators will follow patients longitudinally to assess the primary outcome identified as recurrence of persistent atrial arrhythmias (AA) (atrial fibrillation, atrial flutter or atrial tachycardia as defined by recent guidelines [2]). The investigators hypothesize that patients receiving fibrosis-guided ablation in addition to conventional PVI ablation will have fewer AA recurrences than those who receive PVI ablation alone. The investigators will also examine the efficacy of the fibrosis-guided ablation intervention on a number of secondary or exploratory outcomes including the individual components of the primary outcome (atrial fibrillation, atrial flutter and atrial tachycardia), symptomatic atrial arrhythmia, AF cycle length/regularity/termination, cardiovascular (CV)-related hospitalization, CV-related mortality, quality of life measurements (University of Toronto Atrial Fibrillation Severity Scale (AFSS), and AF burden. The safety of the two interventions will be evaluated by evaluating peri-procedural complications including stroke, peripheral vascular stenosis, bleeding, esophageal injury, cardiac perforation, heart failure, and death.

Atrial fibrillation (AF) is the most common cardiac arrhythmia with a lifetime risk of developing AF of 1 in 4 people aged over 40. Besides hemodynamic compromises stroke remains the most feared complication of AF with an increase in risk by 5-fold. Catheter ablation has evolved as a standardized treatment option in paroxysmal AF. Due to the advanced electrical and structural remodeling the single procedural results of catheter ablation for persistent and longstanding persistent AF are rather disappointing without a proven superiority of any applied strategy compared to others. However, repeated catheter ablation can achieve better results. The surgical (epicardial) approach seems to be more effective, though still a significant amount of failures exist. Checking the epicardial ablation lines and if necessary making additional endocardial lines (which is a hybrid ablation) is expected to be most efficacious in avoiding lesion gaps and providing the most complete lesion set. The study objective of this pilot trial is to compare the safety and efficacy of catheter ablation within 6 months versus a hybrid ablation consisting of endoscopic epicardial surgery combined with endocardial catheter ablation (performed one-stage) in preventing the recurrence of atrial fibrillation (AF) in symptomatic, drug refractory patients with persistent or longstanding persistent atrial fibrillation.

This protocol aims at assessing the efficacy of performing catheter ablation for atrial fibrillation (AF) with laser catheters versus performing it with radiofrequency (RF) catheters. In order to study laser catheter ablation efficacy, MRI analysis of the lesions 3 months after the procedure will be performed in both groups. MRI analysis will detect ablation gaps in the lesions encircling pulmonary veins. The primary endpoint will compare the number of gaps in the laser catheter and the RF group. The secondary endpoint of the study is recurrence of AF after 12 months. The target population of the study is patients with paroxysmal or persistent AF undergoing AF ablation.

Atrial fibrillation (AF) is the most common cardiac rhythm disturbance in adults, with prevalence expected to rise significantly the coming decades. The occurrence of AF is associated with significantly increased mortality as well as morbidity of which cerebrovascular accidents is the most important. Unfortunately treatment options remain limited. Anti-arrhythmic drugs are widely used but have limited efficacy and the potential for toxicity and adverse events are recognized. Recent year's catheter ablation of AF continues to gain acceptance for symptomatic treatment, but recurrence rate are high with need for continuous medication. Thus there is a need to better understand what causes development and triggers episodes of AF as well to introduce new treatment options. Cardiometabolic factors such as obesity, inactivity and sleep apnea (SA) have therefore gained interest. Many patients with AF have chronic sleep apnea, and in the present study the investigators want to explore the interaction between SA and AF. The hypothesis of the present study is that SA may trigger AF and that treatment of SA will reduce the overall burden of AF as well as reduce the recurrence of AF after pulmonary vein ablation. To test the hypothesis the investigators will implant a Reveal device that continuously records the hearts rhythm of 100 patients with paroxysmal AF and concomitant SA. Initially the influence of SA on onset of AF will be examined, and the patients will then be randomized to treatment of SA or not and the influence on total AF burden recorded both before and after ablation.

The purpose of this study is to determine that a new drug called "Rivaroxaban®" is effective in preventing patients from forming clots after their heart rhythm has been reset by the cardiologist with an electrical device.

Background and study concept: Atrial fibrillation is the new global epidemic in cardiology. With improved survival from other cardiovascular diseases and longer living in general, the incidence and prevalence of AF rise dramatically in all developed countries with an estimated life time risk of one in four for all people above the age of 40 years. Similarly in Denmark, the prevalence is estimated to almost double within 2020. It is a fatal arrhythmia with doubled mortality compared to patients with normal sinus rhythm; this primarily caused by an increased risk of stroke and heart failure. In particular stroke is a feared complication with a 70% risk of fatal outcome or lasting handicaps and immense costs for each patient as well as in terms of health costs. Moreover, many AF patients experience a variety of symptoms and have markedly reduced quality of life. Opposed to heart failure patients and patients who have suffered from a myocardial infarction, AF patients are not offered any sort of rehabilitation when diagnosed. Pharmacological treatment of the arrhythmia is challenging. Most often, individual and careful risk evaluation including ultrasound of the heart is obligatory to choose optimal treatment strategy and prophylactic anticoagulation. In case a new anti-arrhythmic drug is started to restore and maintain sinus rhythm, hospitalization for at least two days with heart rhythm monitoring is required to detect any possible potentially dangerous or even fatal arrhythmia as a side effect to the treatment. Additionally, the first new oral anti-arrhythmic AF drug introduced for more than twenty-five years proved to be hazardous in a high-risk AF population and is now only used with strict precautions. To explore the role of alternative treatment strategies and to renew handling of cardiac arrhythmia, we have therefore set out to study the role of physical exercise in AF patients. Our specific study aims are to examine: The effect of physical exercise on AF burden The effect of physical exercise on the risk of cardiovascular hospitalization Method: Our study is an interventional, randomized exercise study. 60 patients older than 18 years with ECG-documented AF will be included if written informed consent is obtained. They will be randomized 1:1 to moderate-severe (80-85% of max capacity) or low intensity (50% of max capacity) training. Exclusion criteria are language barrier, illness inherent with an expected survival shorter than a year, other reasons preventing the patient from training, revealed serious cardiac disease during pre-tests, AF ablation within one year, permanent AF. Both groups are first participating in a nurse-led educational and care program. The program is built on two individual consultations and one team consultation with focus on education in AF. The patients will be thoroughly examined before randomization and after ended training period with special ultrasound of the heart, ECG-monitored test of maximal oxygen uptake on ergometer bicycle, 24 hours measurement of blood pressure and pulse, and blood samples. They will all be taught to use home ECG recorders, a new handheld device. The patients will send ECG's twice daily and if the experience cardiac symptoms for 5 months (during exercise and two months after). When randomized the patients will be divided in teams of ten and trained on separate teams, so the physiotherapist closely can guide the patients in training at the correct intensity level. Measurements: During and after physical exercise the burden of atrial fibrillation is measured by tele-ECG i.e. number of ECGs with atrial fibrillation divided by total number of ECGs. ECG reporting begins after four weeks of physical exercise and continues 2 months after last training session. Recording of hospitalization begins after randomization and continues one year after last training session. All hospitalizations caused by AF or related to the AF disease (relapse of AF, heart failure, stroke, new anti-arrhythmic medication, elective electrical cardioversion, complications to anticoagulation, pacemaker implantation) are recorded. Also, total days in hospital are registered. The AF population is growing on a global scale and the disease attracts immense interest on all international cardiology congresses. New knowledge of the effect of training for the general population as well as the effect in the setting of established disease could have paramount effect for prognosis, quality of life, and health costs as pharmacological treatment is AF still holds challenges.

This is a PI-initiated study that aims to evaluate the efficacy of two different methods of paroxysmal atrial fibrillation (PAF) ablation. There are currently two strategies for PAF ablation that are routinely performed by electrophysiology clinicians: (1) circumferential pulmonary vein ablation (CPVA) and (2) segmental pulmonary vein isolation (SPVI). However, it is not known if one approach is better than the other. This randomized study will evaluate and compare the efficacy of CPVA versus SPVI in subjects undergoing ablation for paroxysmal atrial fibrillation only. Subjects will have a 50/50 chance of receiving either the CPVA or SPVI ablation method.

The purpose of this study is to compare edoxaban to warfarin (with enoxaparin, if needed). It will see if edoxaban prevents stroke and other blood clotting problems as well and as safely as warfarin. People with atrial fibrillation (irregular heartbeat) might be able to join. Their doctors must plan to use shock to make their hearts beat normally. About 2200 people from different countries will join. They will have an equal chance of receiving either treatment. They are anticipated to be in the study for around 82 days. Tests will include physicals and finger-pricks. Participants will provide blood and urine samples.

Stimulants and drugs are often associated with cardiac effects. Caffeine, a therapeutic xanthine, has been described as a sympathomimetic and has shown to have stimulatory effects on the heart. Patients with symptomatic cardiac arrhythmias are generally informed by their physician to stop or significantly reduce caffeine intake. However, in spite of numerous reports that have reviewed the cardiac effects of caffeine, it remains unclear to what extent this stimulant may be detrimental, and what subgroups of patients may be most vulnerable. The investigators propose to evaluate the effects of caffeine in patients with previously diagnosed cardiac arrhythmias. The results of our report will provide important new information for physicians and patients regarding the effects of caffeine on symptomatic cardiac arrhythmias.

Background: The acute coronary syndrome (ACS) is a complication of coronary artery disease (CAD) and associated with increased mortality. Dual antiplatelet therapy of acetylsalicylic acid (ASA) with P2Y12 receptor antagonists such as clopidogrel is a cornerstone in the treatment of patients with advanced CAD. Due to delayed onset of action, intersubject variability or resistance to clopidogrel, different platelet aggregation inhibitors have been developed. Ticagrelor is a reversible P2Y12 receptor antagonist with superior efficacy compared to clopidogrel in the prevention of cardiovascular death in these patients. Atrial fibrillation (AF) is also associated with thromboembolic events and substantial mortality. Beside vitamin K antagonists (VKA, phenprocoumon) for stroke prevention in patients with AF, the direct factor Xa inhibitor apixaban has recently received approval for prophylactic treatment of patients with non-valvular AF. However, there is a lack of efficacy or safety data for the combined impact of antithrombotic drugs in patients requiring arterial and venous thromboembolic prophylaxis due to their underlying co-morbidities. One trial suggests treatment with VKA + clopidogrel without ASA as equal effective as antithrombotic triple therapy (with ASA) in this population. However, the effect in combination with novel oral anticoagulants has not been investigated so far. Study objectives: To evaluate the effect of ticagrelor + apixaban in combination with or without ASA at steady state on markers of coagulation activation and on thrombus size in an ex vivo perfusion chamber experiment. Additionally, plasma samples will be analysed for PK-data (ticagrelor & apixaban concentrations) Study design: A single-centre, prospective, sequential, controlled, analyst-blinded study in two groups. Subjects will receive ticagrelor + apixaban in combination with (study A) or without (study B) ASA. All IMPs will be administered at doses indicated for stroke prevention in AF (lower dose: 2.5mg due to ethical concerns) or ACS. Markers on thrombin generation and platelet activation will be studied in venous blood where coagulation is in resting state and in shed blood where the clotting system is activated in the microvasculature in vivo: prothrombin fragment 1+2 (F1+2), thrombin-anti-thrombin (TAT), β-thromboglobulin (β-TG). Additionally, inhibition of factor Xa activity and concentrations of ticagrelor and apixaban will be assessed in venous blood. Further, thrombus size of clots formed in an ex vivo perfusion chamber will be determined by measurement of D-Dimer and p-Selectin levels. Study population A total of 40 healthy, non-smoking and drug-free male volunteers will be enrolled (study A and B; n = 20 per group). Main outcome variables: β-TG in shed blood Additional outcome variables: F1+2 and TAT in shed blood fibrin formation (D-Dimer) and platelet deposition (p-Selectin) in an ex vivo perfusion chamber model of thrombosis β-TG, F1+2, TAT & inhibition of factor Xa in venous blood PT, aPTT and ACT in venous blood ticagrelor & apixaban plasma concentrations shed blood volume