I. Why should patients with atrial fibrillation have a left ear blocker implanted? Fang Pihua, Department of Cardiovascular Medicine, Fu Wai Hospital, Beijing
Atrial fibrillation is the most common cardiac arrhythmia, with an incidence of 0.4-1%, and there are at least 10 million patients with atrial fibrillation nationwide. The main complication of AF patients is stroke, and the risk of stroke is 5-15 times higher than that of the general population. More than 87% of stroke patients have thromboembolism, and more than 90% of thrombosis originates in the left auricle (LAA). The main drug used to prevent thromboembolism is warfarin, but warfarin has many problems such as poor compliance, troublesome monitoring, and many side effects of the drug. As a new technique for the treatment of atrial fibrillation, left ear occlusion has been proven to be effective and safe in several international clinical studies, and its efficacy is even better than that of oral warfarin. Left-ear occlusion can reduce (1) stroke/embolism/cardiovascular mortality by 40%, (2) cardiovascular mortality by 60%, and (3) all-cause mortality by 34%. With the improvement of blocking r and implantation technology, more and more patients will be treated by this new technology.
II. What patients are suitable for implantation of left ear blocker?
Age >18 years (recommended >65 years)
Non-valvular atrial fibrillation
CHADS2-VAS score ≥2
HAS-BLED score ≥3
Long-term aspirin & clopidogrel available
In conclusion, patients with non-valvular atrial fibrillation have a higher risk of high stroke and need to be treated with anticoagulants such as warfarin, but those who cannot or are not suitable for anticoagulants for various reasons can be considered for implantation of a left ear blocker
How is the CHADS2-VAS score (risk of embolism) calculated?
How is the HAS-BLED score (risk of bleeding) calculated?
V. Which patients are not suitable for implantation of a left ear blocker?
NYHA Heart Failure Classification Class IV
Acute myocardial infarction
Uncontrolled hypertension
With active bleeding
Severe hepatic or renal insufficiency
Abnormal coagulation
History of LAA ligation
Left atrial internal diameter >65 mm
LVEF <30%< p="">
TEE:Suspected or known left atrial intravascular thrombus
Significant atrial septal abnormalities
Post-operative heart valve repair
Post-operative inferior vena cava filter placement
Active infection
Stroke within 1 month
Aspirin allergy
Heart valve disease
Inappropriate heart ear morphology (<17mm, >31mm, available length too short, at physician’s discretion)
VI. How to follow up and anticoagulate after left ear occlusion?
After left ear occlusion, warfarin should be taken for the first 45 days; TEE should be performed at 45 days, and if the occlusion is good (<5mm< span="">), warfarin should be stopped and aspirin and clopidogrel should be taken instead; TEE should be rechecked at 6 months after the operation, and if the occluder is still well occluded, aspirin should be taken alone for lifelong maintenance.
7.What is the structure of WATCHMAN blocker?
WATCHMAN blocker consists of 3 parts.
WATCHMAN blocker.
(1) Nickel-titanium alloy frame: Available sizes: 21, 24, 27, 30, 33 mm (diameter) with 10 movable fixed barbs surrounding it, designed to engage the left auricular tissue to ensure its maintenance and stability, and contoured to fit most left auricular anatomy.
(2) 160 micron membrane: a polyethylene terephthalate (PET) cap is used to cover the surface of the nitinol framework, designed to block thrombus dislodgement from the left heart ear and to facilitate the endothelialization healing process on the surface of the blocker. As shown below.
2. Through-Septum Sheath (AccessSheath)
Available in 2 types: double-curved or single-curved
Outer diameter 14F (4.7mm), inner diameter 12F (4mm)
Working length 75cm
What is the procedure of WATCHMAN blocking device implantation?
1. Evaluation of the left auricle: The morphology, caliber and depth of the left auricle are determined by excluding the left auricle thrombus through esophageal ultrasound (TEE).
2. Release criteria after blocker implantation.
All release criteria (PASS) must be met prior to blocker release
Position C blocker slightly distal or just above the left ear opening
Anchor C Fixed barb engagement/blocker stability
Size C 8-20% compression of the blocker relative to the original size
Seal C Blocker across the opening, covering all left auricular leaflets
What international clinical trials have been done on the effectiveness and safety of the WATCHMAN blocker?
The WATCHMAN blocker has been proven to be effective and safe in several large clinical trials, two of which are highlighted below (Protect AF and Prevail)
X. What is the experience of the National Cardiovascular Center Fu Wai Hospital?
The first Watchman case in China was implanted at Fu Wai Hospital on March 18, 2014.
Patient Cao, male, 70 years old, had persistent AF for 10 years, history of hypertension for 10 years, and history of diabetes mellitus for 5 years.
At present, nearly 30 cases of left ear blockers have been implanted, all of which have achieved satisfactory results.
This article is authorized by Dr. Pihua Fang.