Clinical Research Directory

LAmbre™ II Left Atrial Appendage Occluder and Occluder Delivery System for Patients With Non-Valvular Atrial Fibrillation

Worldwide, atrial fibrillation (AF) is the most common cardiac arrhythmia in adults. The prevalence of AF gradually increases with age; its prevalence is 0.5% \~ 0.8% among 45 \~ 59 year-olds, 1.8% \~ 5.9% among 60 \~ 69 year-olds, and 6.7% \~17.9% among \> 79 year-olds. Thromboembolic complications are the leading cause of death and disability in patients with AF, with ischemic stroke being the most common complication. AF significantly increases the risk of stroke by 3- to 5-fold due to thrombosis caused by abnormal atrial beat. The overall risk of ischemic stroke in patients with AF is 20% \~ 30%, and strokes due to atrial fibrillation account for 20% of all strokes. In the current 2023 ACC/AHA/ACCP/HRS Guideline, percutaneous LAAC has been classified as a Class 2a indication for stroke prevention in patients with AF, a moderate to high risk of stroke, and a contraindication to long-term oral anticoagulation due to a nonreversible cause. However, the implantation procedure does have adverse effects which include serious pericardial effusion, procedure-related ischemic stroke, and device embolization. Due to the anatomical diversity of the LAA, certain patients are not candidates for this device. The LAmbre™ Left Atrial Appendage Closure System, manufactured by Lifetech Scientific (Shenzhen) Co.Ltd., is the first generation of LAmbre LAAO device which is CE-marked and is current approved in Hong Kong Hospital Authority for regular clinical use. It consists of a LAA Occluder and a Delivery System and is a percutaneous transcatheter device intended to prevent thrombus embolization from the left atrial appendage in patients who have nonvalvular atrial fibrillation. This self-expanding LAA Occluder consists of an umbrella and a cover connected by a central waist. Although the first generation of LAmbre LAAO device is associated with high implantation success rate of 99.7% and a relatively low major procedure-related complication rate of 2.9%, to better match the challenging anatomy of the LAA and to further improve procedural safety, the first generation of LAmbre LAAO device has been upgraded. The LAmbre™ II Left Atrial Appendage Occluder, designed to prevent thrombus embolization and reduce the risk of bleeding events in patients with non-valvular atrial fibrillation, is being evaluated in a prospective, single-center, single-arm First In Man (FIM) study. The study, conducted at the Prince of Wales Hospital, Chinese University of Hong Kong, aims to assess the preliminary safety and feasibility of the device and its Occluder Delivery System in 10 subjects who are at increased risk for stroke and systemic embolism, either due to their anticoagulation therapy eligibility or contraindications. The enrollment period is expected to take approximately 6 months and subjects will have follow-up before discharge and at 30 days, 3M, 6M, 12M months post-operation. The total study duration is expected to be approximately 19 months.

Applause Study I - Append System Early Feasibility Study

This early feasibility study is intended to evaluate the safety and feasibility of the Append System for eliminating the left atrial appendage (LAA) through a transcatheter procedure that invaginates and ligates the LAA tissue.

Stroke Risk Assessment and Markers of Blood Clotting in Patients With Newly Diagnosed Non-valvular Atrial Fibrillation (NVAF), Who Have Not Received Oral Anticoagulation Therapy (OAC-therapy) Prior to Inclusion

Background: Atrial fibrillation (AF) is the most common heart rhythm disorder worldwide. Globally, there are 37.5 million people with AF. AF increases the risk of death, heart failure, and stroke, which severely affect patients and also lead to high healthcare costs. Around 25% of all strokes are caused by AF, and patients with stroke due to AF tend to have a higher risk of death and more disability compared to stroke patients without AF. Stroke prevention is, therefore, an important part of AF treatment, in which blood thinning medication has an important role. However, blood thinners increase the risk of bleeding. Therefore, it is important to divide patients with AF into different risk groups, known as risk assessment, to figure out who will benefit the most from blood thinners. To be able to divide patients into different risk groups, various stroke risk assessment tools have been developed, such as the CHA2DS2-VASc score and the ABC-stroke score. The most commonly used tool is the CHA2DS2-VASc score, including only clinical risk factors, such as high blood pressure, diabetes, etc. The ABC-stroke score, which includes blood markers of heart function, has been proven to outperform the CHA2DS2-VASc score in terms of predicting stroke in AF patients. However, the CHA2DS2-VASc score remains the primary stroke risk assessment tool for AF patients in current guidelines. After looking at the different risk factors, patients are divided into three groups: low, intermediate, and high risk. High-risk patients must take blood-thinning medication for life, while low-risk patients do not need it. In the medium-risk group, it remains uncertain whether blood thinners should be given or not. Despite the broad use of the CHA2DS2-VASc score, the score itself has limitations. The score does not include important factors, such as the duration of AF, the size and function of the upper heart chambers, as well as the stiffness of the heart, and markers of blood clotting, which are proven markers of a state that inceases the risk of blood clots. Furthermore, the CHA2DS2-VASc score does not consider whether heart failure, high blood pressure, and diabetes are well-controlled or not, which could lead to overuse of blood thinners. Therefore, the current risk assessment tools for patients with AF are incomplete, and improvements are needed. Overall hypothesis: Overall hypothesis is that the different components of the CHA2DS2-VASc score and ABC-stroke score affect blood clotting markers differently, depending on whether conditions like heart failure, high blood pressure, and diabetes (modifiable risk factors) are well-controlled or not. Investigators also expect to see differences in blood clotting markers across different stroke risk groups (low, intermediate, and high risk, based on the CHA2DS2-VASc score and ABC-stroke score) in AF patients who have not yet started blood thinning medication. Furthermore, investigators believe that the duration of AF, the size/function of the upper heart chambers, as well as the stiffness of the heart, can reflect an increased risk of blood clots in AF patients. Overall goal of the study: The overall goal of the study is to help improve the current tools used to assess the risk of stroke in patients with newly diagnosed AF. This will be done by adding more factors to the current risk assessment tools that reflect an increased risk of stroke, such as the burden of AF, the size/function of the heart's upper chambers, as well as the stiffness of the heart, and using biomarkers that show the blood's ability to clot as a substitute measure for stroke risk. Methods: The study is a cross-sectional, single-center observational study and will take place at Esbjerg Hospital - University Hospital of Southern Denmark, involving collaboration between the Unit for Thrombosis Research, Department of Clinical Diagnostics and the Department of Cardiology. The study population will consist of 150 participants with newly diagnosed AF. The participants must not be taking a specific type of blood thinner, called anticoagulant therapy (OAC-therapy), before being included in the study. The participants will be recruited with the help of the general practitioners (GPs). The general practitioners will be thoroughly informed about the study and the importance of waiting to start OAC-therapy until the participants have been seen at the cardiology outpatient clinic. The participants will be scheduled for a blood test, an ultrasound of the heart (echocardiography), and a 7-day heart rhythm monitoring within 4 days after their first meeting with the GP.

Apixaban Versus Rivaroxaban in Non Valvular Atrial Fibrillation

The investigators will first measure the maximum concentration (after 2 hours of intake) and the residual concentration (just before the next intake) after at least 15 consecutive days of treatment. In order to be able to study the stability of the anti-Xa activity of Apixaban vs Rivaroxaban, as well as their impact on the risk of thromboembolic events or hemorrhagic events, clinical follow-up and a determination of maximum and residual activity are necessary, ideally at 3 to 6 months (compared to studies carried out in the literature). This evaluation would be made according to a multivariate analysis taking into consideration the other clinical-biological data relating to the patient, namely renal function, liver function, CHA2DS2-VASc score, HAS-BLEED score, treatment compliance, etc.