Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and confers roughly a fivefold increase in ischemic stroke risk.1 In non-valvular AF (NVAF), thrombus arises predominantly in the left atrial appendage (LAA), which accounts for the vast majority of cardioembolic sources. “Valvular AF” is a specific term: it refers to AF in the setting of moderate–severe rheumatic mitral stenosis or a mechanical prosthetic valve; other valve disease does not meet this definition.

Oral anticoagulation (OAC) has long been the cornerstone of stroke prevention in AF. However, many patients have absolute or relative contraindications (e.g., prior major bleeding, high hemorrhagic risk) or develop adverse effects, adherence challenges, drug–drug interactions, or renal limitations that complicate lifelong therapy.

Left atrial appendage occlusion (LAAO) provides a mechanical alternative that addresses the LAA as the primary thrombus source in NVAF. Surgical strategies evolved from ligation to excision/stapling; over the last two decades, percutaneous, catheter-based LAA closure (LAAC) has become the dominant approach.

Cumulative evidence from randomized trials, prospective registries, and long-term follow-up supports LAAC as a reasonable alternative to OAC in appropriately selected patients, with noninferior stroke prevention and favorable bleeding profile.

How Does Percutaneous Endocardial LAAO Work?

Left atrial appendage is sealed from inside the left atrium using devices made of nitinol frame covered with fabric (figure1, panel A). Devices are placed inside the LAA and secured using the radial force and small anchors. This prevents exit of clots from LAA immediately after the procedure.

Over time, cardiac endothelium grows over the devices and prevents both entry of blood in LAA and exit of clots from LAA (figure1, panel B). Watchman FLX Pro™ and Amulet™ are two FDA approved devices available in US.

Who Should Consider LAAO?

Great candidates

• AF with elevated stroke risk: CHA2DS2-VASc score ≥2 in men or ≥3 in women (e.g., prior stroke/TIA/systemic embolism, age, hypertension, diabetes, heart failure, vascular disease).
• High bleeding risk or OAC challenges: Prior intracranial hemorrhage, major GI bleeding, recurrent epistaxis/menorrhagia on OAC, chronic anemia, thrombocytopenia, labile INRs, interacting medications, advanced CKD, or occupational hazards (frequent falls, high-impact activities).
• Intolerance or strong preference to avoid lifelong OAC after a shared decision-making discussion of risks, benefits, and alternatives.

Reasonable candidates (nuance matters)

• Patients doing well on OAC who prefer a non-pharmacologic, one-time solution because of long-term bleeding concerns, lifestyle constraints, or professional demands.
• Patients already scheduled for other left atrial procedures (e.g., AF ablation) when a combined strategy can streamline care

Typically, not LAAO candidates

• Valvular AF due to moderate–severe rheumatic mitral stenosis or mechanical valves (different embolic mechanisms and anticoagulation indications).
• Inability to take even short-term antithrombotic therapy post-implant. (Don’t wait until no antithrombotic is possible; outcomes are better when limited post-implant therapy is still feasible.)
• Unsuitable LAA anatomy for device placement (uncommon; determined by imaging).

How is the Procedure Performed?

Think of the LAA as a small side pocket off the left atrium. During LAAC, an umbrella-like device is deployed across the LAA ostium to seal the pocket.

Typical steps on procedure day

1. Anesthesia & imaging. General anesthesia or deep sedation is used. Imaging is via transesophageal echocardiography (TEE) or intracardiac echocardiography (ICE). ICE avoids esophageal instrumentation and can facilitate same-day discharge in many programs.
2. Venous access & transseptal puncture. Via femoral vein, catheters enter the right atrium; a controlled puncture across the interatrial septum provides left atrial access—standard EP technique performed frequently in AF ablation and LAAC.
3. Device sizing & placement. The LAA ostium and landing zone are measured to select an appropriately sized device. The most widely used systems are the Watchman™ family and Amplatzer Amulet™; both secure at the ostium via radial force and anchors.
4. Verification & release. Under live fluoroscopy and ultrasound, the team confirms position, stability (tug tests), seal (assesses peri-device leak), and freedom from interference with nearby structures (mitral valve, pulmonary veins). The device is then released.
5. Recovery. Many patients go home the same day or after one night; avoid heavy lifting for about a week.

LAAO vs lifelong anticoagulation (at a glance)

Choosing Devices and Imaging Strategies

Device selection

LAA anatomy varies widely (shape, ostial size, lobes, depth). Both Watchman and Amulet cover a broad range; selection hinges on anatomic fit and clinical goals (e.g., speed of anticoagulation de-escalation). Operator experience, device availability, and center-level outcomes also matter.

Imaging (TEE vs ICE)

• TEE: excellent image quality10; often requires general anesthesia and can cause a sore throat post-procedure.
• ICE: avoids the esophagus and commonly enables a smoother same-day experience; attractive for patients with esophageal disease, high aspiration risk, or those who want to avoid TEE. Both are safe and effective in experienced hands; most centers individualize the approach.

Safety Profile and Risks

LAAO is a catheter procedure performed thousands of times per year worldwide. In experienced hands, serious complications are uncommon, but it’s important to know that there are rare instances of pericardial effusion, stroke/TIA, vascular access complications and device embolization.7 During follow up imaging, we may see a device related thrombus or peri-device leaks. Overall, contemporary data show steadily improving safety as devices and operator experience have advanced. PINNACLE FLX trial studied the Watchman FLX device, which is the most used platform worldwide. During this study neither device embolism nor periprocedural pericardial effusion requiring drainage were reported. The primary efficacy endpoint, defined as absence of significant peri-device leak > 5 mm at 12 months, was achieved in 100% of patients. Overall, there was 0.5% rate of significant complication during this study.

Follow-Up and Medications After Laac

Most patients are discharged on either short-term OAC or dual antiplatelet therapy (DAPT), tailored to bleeding risk and device type. Follow-up imaging with TEE or cardiac CT is typically performed 4–12 weeks after implant to assess for peri-device leak and device-related thrombus (DRT). Incomplete endothelialization at 6–12 weeks is common and does not by itself mandate therapy changes. If there is no DRT and no significant leak (>5 mm), patients usually de-escalate to lower-intensity therapy, with a goal of single antiplatelet therapy (aspirin 81 mg) by ~6 months. Given the heterogeneity of bleeding risk, post-implant regimens are individualized.

Future Directions

LAAC technology continues to improve with devices designed for better conformability and sealing, aiming to further reduce thromboembolic and bleeding events. Ongoing randomized trials—CHAMPION and CATALYST—are evaluating LAAC in patients who can tolerate OAC but prefer a device-based strategy. In parallel, same-session AF ablation plus LAAC13 is increasingly used when both indications coexist, offering a streamlined care pathway in selected patients.

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References:

1. Ohlrogge AH, Brederecke J, Schnabel RB. Global Burden of Atrial Fibrillation and Flutter by National Income: Results From the Global Burden of Disease 2019 Database. JAHA. 2023;12(17):e030438. doi:10.1161/JAHA.123.030438
2. Blackshear JL, Odell JA. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg. 1996;61(2):755-759. doi:10.1016/0003-4975(95)00887-X
3. Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2024;149(1). doi:10.1161/CIR.0000000000001193
4. Van Gelder IC, Rienstra M, Bunting KV, et al. 2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS). European Heart Journal. 2024;45(36):3314-3414. doi:10.1093/eurheartj/ehae176
5. Saw J, Holmes DR, Cavalcante JL, et al. SCAI/HRS Expert Consensus Statement on Transcatheter Left Atrial Appendage Closure. Journal of the Society for Cardiovascular Angiography & Interventions. 2023;2(3):100577. doi:10.1016/j.jscai.2022.100577
6. Reddy VY, Doshi SK, Kar S, et al. 5-Year Outcomes After Left Atrial Appendage Closure: From the PREVAIL and PROTECT AF Trials. J Am Coll Cardiol. 2017;70(24):2964-2975. doi:10.1016/j.jacc.2017.10.021
7. Kar S, Doshi SK, Sadhu A, et al. Primary Outcome Evaluation of a Next-Generation Left Atrial Appendage Closure Device: Results From the PINNACLE FLX Trial. Circulation. 2021;143(18):1754-1762. doi:10.1161/CIRCULATIONAHA.120.050117
8. Lakkireddy D, Thaler D, Ellis CR, et al. Amplatzer Amulet Left Atrial Appendage Occluder Versus Watchman Device for Stroke Prophylaxis (Amulet IDE): A Randomized, Controlled Trial. Circulation. 2021;144(19):1543-1552. doi:10.1161/CIRCULATIONAHA.121.057063
9. Piccini JP, Zeitler EP, Yeh R, et al. PO-02-184 OUTCOMES WITH WATCHMAN FLX PRO IN EVERYDAY CLINICAL PRACTICE: EARLY RESULTS FROM SURPASS PRO. Heart Rhythm. 2025;22(4):S318. doi:10.1016/j.hrthm.2025.03.666
10. Goyal SK, Hyder S, Liu S, Vannan MA. Isoproterenol-Assisted Differentiation Between Sludge and Organized Thrombus to Guide Left Atrial Appendage Occlusion. JACC: Clinical Electrophysiology. 2023;9(1):111-116. doi:10.1016/j.jacep.2022.10.026
11. Alkhouli M, Chaker Z, Alqahtani F, Raslan S, Raybuck B. Outcomes of Routine Intracardiac Echocardiography to Guide Left Atrial Appendage Occlusion. JACC: Clinical Electrophysiology. 2020;6(4):393-400. doi:10.1016/j.jacep.2019.11.014
12. Sanchez CE, Goyal SK, Brown LM, et al. How to Use 3D Intracardiac Echocardiography in Left Atrial Appendage Closure. JACC: Clinical Electrophysiology. 2025;11(5):1087-1096. doi:10.1016/j.jacep.2025.01.014
13. Wazni OM, Saliba WI, Nair DG, et al. Left Atrial Appendage Closure after Ablation for Atrial Fibrillation. N Engl J Med. 2025;392(13):1277-1287. doi:10.1056/NEJMoa2408308

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Sandeep K. Goyal, MD, FHRS, FACC

Sandeep K Goyal, MD earned his medical degree from Maulana Azad Medical College in New Delhi, India. He completed his cardiology and cardiac electrophysiology fellowships at Vanderbilt University School of Medicine in Nashville, Tenn.

He currently serves as medical director for cardiac electrophysiology laboratories at Piedmont Atlanta Hospital. He also directs the left atrial appendage occlusion and EP research programs at PHI.

He manages all aspects of arrhythmia care with special interest in management of atrial fibrillation to reduce risk of stroke and its adverse effects on quality of life.