Active clinical trials for "Atrial Fibrillation"

The objective of the study is:Phase I: To validate or otherwise determine the Chinese-specific appropriate contact force during PVI in PAF.Phase II: To evaluate the effectiveness and safety of ablation guided by the appropriate contact force.

To obtain a better understanding on the comparative effectiveness of rivaroxaban and vitamin K antagonists (VKA) for stroke prevention in patients with non-valvular atrial fibrillation (SPAF) in a real-life setting

Apixaban is an anticoagulant which is increasingly being used to prevent stroke in atrial fibrillation (AF). Phase III clinical trials have demonstrated that apixaban is efficacious and safe for the overall AF population; however, patients older than age 85, with creatinine clearance <40mL/min, or who weighed <50kg were poorly represented in these trials, yet they are commonly seen in real-world clinical scenarios. Advanced age, poor renal function, and low body weight are all associated with elevated drug levels, and elevated drug levels are associated with an increased risk of bleeding. Therefore, clinicians are concerned about the risk of bleeding and are unsure of how best to treat this patient population. Although other anticoagulants are available, apixaban is attractive because it has a low rate of bleeding, low dependence on the kidneys for clearance, and does not require frequent ongoing monitoring and dose adjustment. This study will include patients taking apixaban who were not well-represented in phase III trials - those with age >85, creatinine clearance <40mL/min, or weight <50kg - who are also at increased risk of having elevated drug levels due to these clinical characteristics. Participants will have apixaban levels measured, and those with persistently elevated levels will have their dose reduced. Drug levels will be measured again after dose reduction to determine if the levels are reduced without becoming dangerously low.

RATIONALE / CONTEXT The ECG records the electrical activity propagating along cardiac cells (from the atria to the ventricles). The standard 12 ECG leads placed on the chest measure the global activation of the heart and do not have the ability to detect small-scale disturbances or to pinpoint ectopic activity. By the 1960s, multiple electrodes were placed around the chest to try to understand the complexity of the distribution of electrical activity in relation to the single cardiothoracic geometry of each individual. The safety of this method is similar to the ECG but its superiority has been demonstrated by the detection of anomalies imperceptible to the standard ECG. The accuracy of the technique in localizing rhythm disturbances is on the order of 5 mm. OBJECTIVES Main objective: To evaluate the utility of noninvasive mapping during persistent AF electrophysiology procedure Secondary objectives: Compare the effectiveness of noninvasive mapping compared to conventional standard of care methods for AF mapping and ablation procedure. Evaluate the absence of recurrence of persistent AF after a follow up of 12 months after the procedure during a scheduled hospitalization. DIAGRAM OF RESEARCH European Diagnostic Study, feasibility, non-randomized, multi center RESEARCH PROCEDURES A trained clinical specialist places 252 dry gelled ECG electrodes on the patient's torso. The 252 ECG electrode array is hooked up to the CardioInsight system and body surface ECG recordings are made during the patient's arrhythmia. The patient is then sent to the radiology department for a CT scan (no contrast) to image both the heart and electrodes on the patient's torso. A trained clinical specialist from CardioInsight then segments the CT DICOM images from the CT scan to obtain epicardial anatomy and establish heart-torso geometry. The electrograms are processed by the system to produce movies of fibrillatory activity (both focal activity, and rotor activity). PROCEDURAL ENDPOINTS Primary endpoint: Acute AF termination to atrial tachycardia or sinus rhythm Secondary outcome criteria: Reduction in RF time compared to standard of care (historical control - comparable patient population) Reduction in procedure time compared to standard of care (historical control - comparable patient population) Freedom from persistent AF at the end of the 12 months F/U period STUDY SIZE The sample size was estimated at 100 patients, with up to 20 patients per center STUDY CENTERS 8 Centers : Brugmann - Brussels (Belgium) Clinique Pasteur - Toulouse (France) Medizinische Klinik und Poliklinik - Mainz (Germany) University ed Herzzentrum Freiburg Bad Kozingen (Germany) Deutsches Herzzentrum München, Munich (Germany) Kerkhoff Klinik, Bad Nauheim, (Germany) Sint-Jan Sint-Franciscus Xaverius, Brugge (Belgium) Clinique Ambroise Paré, Paris, France EXPECTED OUTCOME In patients referred for ablation of persistent AF, ECG mapping data will be correlated to the invasive procedure. It is expected that procedure time will be statistically shorter and total RF energy delivery is expected to be smaller than that of standard of care for AF treatment.

This is an observational registry study aiming to collect data on efficacy and safety of the single chamber Biotronik DX system with enhanced atrial diagnostics. The minimal follow-up period is 24 months. All analyses on the data will be done post-hoc; the study does not intend to confirm any pre-specified hypotheses.

Warfarin (Coumadin) is a prescribed "blood thinner" medication used to make the blood less thick in people with high risk of forming blood clots. Despite the various methods to monitor this drug, life-threatening bleeding is a common undesired effect and might result in patient death. Patients starting warfarin therapy may require several weeks or even months to reach the appropriate blood level of warfarin. This blind practice could place the patient at high risk. There are several demographic and clinical factors that significantly influence how much warfarin the patient needs to attain the desired response. Genes, which control hereditary traits, are also important. Now, the investigators know that by using the information encoded in patient's genes the investigators are able to individualize the therapy. Two genes are considered to be involved in warfarin response (CYP2C9 and VKORC1). This study proposes to ascertain what CYP2C9 and VKORC1 variants are present in warfarin-treated Puerto Rican patients. To this purpose, a novel physiogenomic array comprising 384 variants in 222 genes of cardio-metabolic relevance will be used so the investigators are able to determine the structure of the Puerto Rican population in terms of ancestral contributions and how the admixture may impact the prevalence of CYP2C9 and VKORC1 variants. Secondly, the investigators will assess the association of these variants to clinical responses in order to develop a better method of dose estimation. The expected result is the improvement of warfarin therapy in Puerto Ricans. The proposed study will fill a gap in the knowledge of warfarin pharmacogenetics, providing new information on the prevalence of CYP2C9 (metabolism) and VKORC1 (sensitivity) polymorphisms in Puerto Ricans as well as their role in the warfarin response variability observed in this admixed population.

The purpose of this study is to investigate the complications of cardioversion of acute (<48 hours duration) atrial fibrillation (AF). Primary Outcome Measures: - Incidence and predictors of thromboembolic complications, especially stroke, and death <31 days after cardioversion of acute AF Secondary Outcome Measures: Number of therapy non-responder and early recurrence of AF Bleeding complications during the 31 days follow-up Hemodynamic complications of cardioversion Estimated Enrollment: 3000 cases Study Start Date: Jun 2011 Estimated Study Completion Date: December 2011

Atrial fibrillation (AF) is associated with decreased atrial contractility which is associated with stroke. Decreased contractility becomes apparent after cardioversion of atrial fibrillation, a short period (weeks) during which stroke risk is increased. Improved contractility immediately after cardioversion may prevent arrhythmia progression. In addition, it may reduce the stroke risk. Vernakalant is a new antiarrhythmic drug able to convert atrial fibrillation to sinus rhythm and at the same time increase atrial contractility. The latter has not yet been shown in humans and is subject of the present investigation. Our hypothesis is that in humans the contractility of the atria is higher after administration of vernakalant compared to flecainide. If indeed vernakalant improves atrial contractility after cardioversion further studies into the effect on long-term arrhythmia progression and stroke prevention may follow.

Over the past decade, techniques have been refined which permit an enormous amount of information relevant to disease mechanisms to be gained from the examination of heart tissue. The Cardiovascular Institute has extensive experience with these techniques, and has utilized them to examine other heart disease substrates. In this study, the investigators propose to obtain heart tissue at the time of cardiac surgery which would otherwise be discarded. Their plan is to examine this tissue and correlate their findings with clinical data. Their hope is that the proposed study will provide insight into atrial physiology, including the molecular mechanisms underlying atrial disease and the potential development of atrial fibrillation (AF).

New anticoagulants are being introduced to replace warfarin. These drugs do not require monitoring and are safer. There is currently no recommended way to reverse these drugs rapidly in the event of undue bleeding or need for emergency surgery. This is a lab study to look at ways to reverse the drugs rapidly