Lifetech LAmbre™ Left Atrial Appendage (LAA) Closure System Post-Market Clinical Follow-up Study

Atrial fibrillation (AF) is the most common cardiac arrhythmia causing ischemic stroke. The CHA2DS2-VASc score was developed to estimate the stroke rate in patients with non-valvular AF, and high scores predict a raised annual stroke risk. The yearly stroke risks without treatment in patients with CHA2DS2-VASc Scores 2 and 9 are 2.2% and 15.2% respectively. For patients with increased stroke risk (CHA2DS2-VASc score ≧2), warfarin or other novel oral anticoagulants (NOAC) are recommended for stroke prevention.

Despite the effectiveness of current pharmacological therapies for stroke prevention in atrial fibrillation, around 20% of patients discontinue therapy - whether new oral anticoagulants (NOAC) or warfarin because of side effects and/or bleeding. In addition, warfarin needs to be dosed individually to target an international normalized ratio (INR) of 2-3 for striking an optimal balance between bleeding and ischemic stroke events. This, combined with drug-drug interaction that occurs with both NOACs and warfarin, results in inadequate stroke protection in a substantial portion of AF patients. The LAA is the source of 90% of cardiac emboli attributed to stroke events. This is a windsock-like structure on the lateral border of the left atrium with internal trabeculations, and being a confined space is prone to blood stasis and thrombus formation.

Currently, there are surgical, epicardial, and percutaneous techniques for occluding this structure in order to reduce stroke in AF patients who cannot take long-term oral anticoagulants, and the percutaneous route is intuitively the most attractive given its relative non-invasiveness. The two devices in most widespread use for percutaneous LAA closure worldwide are the Watchman (Boston Scientific, Natick, MA, USA) and the Amplatzer Cardiac Plug (ACP) (Abbott, IL, CA USA). However, both devices have limitations including the need for relatively large delivery sheaths (9-14 French) and limited recapture and repositioning capabilities.

LAmbre™ LAA Closure System (Lifetech Scientific, Shenzhen, China) is a novel self-expanding LAA occluder constructed from a nitinol mesh and polyester membranes and consists of an umbrella and a cover connected by a short central waist. The device is delivered by an 8-10 French sheath and has full recapture and repositioning capabilities. LAmbre™ LAA Closure System received the CE mark in June 2016.

This PMCF study will be carried out following the CE mark of the LAmbre™ LAA Closure System and is intended to confirm the effectiveness and safety of the LAmbre™ LAA Closure System.

Inclusion criteria

• Patients must be at least 18 years of age;
• Patients with non-valvular paroxysmal, persistent, or permanent atrial fibrillation with long-term sustainability scheduled for interventional LAA closure;
• Patient characteristics consistent with the corresponding IFU and sizing guidelines*;

• Note: Choose a device that is 3-8mm larger than the landing zone diameter.
• The patient or legally authorized representative has been informed of the nature of the study, agrees to its provisions, and has provided written informed consent, approved by the appropriate Ethics Committee (EC);
• The patient agrees to comply with the requirements of the study including the 3-year follow-up.

Warning: The device sizing is based on angiographic measurements.

Exclusion criteria

• Any contra-indication mentioned in the corresponding IFU*;

• Note: In IFU, the Left Atrial Appendage Closure System is contraindicated for the following:

• Patients' LAA anatomy is not suitable for the REF of the device.
• Patients with intracardiac thrombus.
• Patients with active endocarditis or other infections causing bacteremia.
• Patients where the placement of the device would interfere with any intracardiac or intravascular structures.
• Patients with contraindications to X-ray and/or trans-esophageal echocardiographic examinations.
• Patients with known hypersensitivity to nickel.
• Currently participating in other investigational drug- or device studies;
• Patient who is pregnant, planning to become pregnant or breastfeeding;
• Patients cannot tolerate transoesophageal echocardiogram (TEE).