Atrial fibrillation raises the lifetime risk of stroke roughly fivefold, and for decades, physicians have relied on anticoagulants to lower that risk. Warfarin eventually gave way to direct oral anticoagulants, which offer simpler dosing and an improved safety profile for many patients. But anticoagulation still comes with a trade-off: reducing the risk of a clot can also increase the risk of bleeding.
For many patients, that trade-off makes sense. For others, a history of serious bleeding or other risk factors can make long-term anticoagulation difficult to manage. That’s where left atrial appendage occlusion, or LAAO, can offer another option.
The procedure falls within the structural heart work of Jaime Caballero, MD, an interventional cardiologist in Tampa whose practice includes catheter-based treatments for patients with complex cardiovascular conditions.
LAAO takes an anatomical approach to stroke prevention. In patients with non-valvular atrial fibrillation, most blood clots that lead to stroke form in the left atrial appendage, a small pouch connected to the left atrium. When the atrium no longer contracts normally, blood can collect in the appendage and form a clot. A catheter-delivered device can close off the pouch, reducing the chance that a clot from that area will enter the bloodstream.
More than 600,000 devices have now been implanted worldwide, making LAAO an established procedure rather than an experimental one. The more important question for physicians is deciding which patients are most likely to benefit from it.
Who the Guidelines Actually Point Toward
The clearest candidates for LAAO are patients who face a significant stroke risk but cannot safely remain on long-term anticoagulation. Current ACC/AHA/ACCP/HRS guidance recommends LAAO as Class IIa for patients with a CHA2DS2-VASc score of 2 or higher who have a contraindication to long-term anticoagulation.
That group can include patients with a history of intracranial hemorrhage, recurrent gastrointestinal bleeding without a correctable source, hereditary bleeding disorders, or other circumstances that make continued anticoagulation unsafe.
The recommendation changes for patients who simply prefer not to take a daily anticoagulant. In those cases, the guidelines give LAAO a Class IIb recommendation, meaning the procedure may be reasonable, but the evidence is less established.
The patients enrolled in the major LAAO trials also don’t represent everyone with atrial fibrillation. Researchers generally selected people with elevated stroke risk and, in some of the earlier studies, documented difficulty tolerating anticoagulation. Physicians, therefore, need to consider the individual patient rather than assume that everyone with atrial fibrillation should undergo closure.
That evaluation starts with a careful review of the patient’s history. A physician assessing matching therapy to bleeding risk may consider factors such as a HAS-BLED score of 3 or greater, chronic kidney disease, previous major bleeding, advanced age combined with fall risk, or the need for antiplatelet therapy after coronary stenting.
Some patients, however, may not qualify regardless of their bleeding risk. Active infection, an existing left atrial appendage thrombus, limited life expectancy, or anatomy that cannot accommodate an adequate seal can all weigh against the procedure.
What the Newest Trials Changed, and What They Did Not
Recent randomized trials have added useful information to the LAAO conversation, although they haven’t answered every question.
The OPTION trial randomized 1,600 patients with atrial fibrillation who had undergone catheter ablation to either LAAO or continued oral anticoagulation. After 36 months, the composite rate of death, stroke, or systemic embolism was 5.3 percent in the closure group and 5.8 percent in the anticoagulation group, which met the study’s criteria for noninferiority.
Non-procedural bleeding also occurred less often with LAAO. For patients who have undergone ablation and remain at risk for stroke while also facing concerns about long-term bleeding, those findings provide additional support for considering closure.
CHAMPION-AF enrolled 3,000 patients across 141 sites. Unlike some earlier LAAO studies, this study included patients considered suitable candidates for a direct oral anticoagulant. Participants had a mean age of 71.7 years and a mean CHA2DS2-VASc score of 3.5.
The study found a composite rate of cardiovascular death, stroke, or systemic embolism of 5.7 percent with LAAO compared with 4.8 percent with a DOAC, meeting the prespecified noninferiority margin. Non-procedure-related bleeding favored the device as well, occurring in 10.9 percent of patients compared with 19.0 percent of those taking a DOAC.
The study also produced findings that physicians should consider when discussing the procedure. Ischemic stroke or systemic embolism occurred in 3.2 percent of the device group compared with 2.2 percent of the DOAC group. Imaging detected device-related thrombus in 4.8 percent of patients, with clinically relevant cases occurring in 1.8 percent. When researchers included procedural bleeding, major bleeding occurred in 5.9 percent of the LAAO group and 6.4 percent of the DOAC group. Serious procedure-related adverse events occurred in 2.3 percent of cases.
Independent commentators also raised questions about the trial’s lower-than-expected event rates, which made it easier for the study to meet its noninferiority margin. The separately funded CLOSURE-AF trial, which enrolled a higher-risk population, found standard medical care superior to LAAO on its composite endpoint.
Taken together, these studies support LAAO as an important option for patients who cannot safely remain on anticoagulation and provide additional evidence for selected patients after ablation. They don’t establish LAAO as a routine replacement for anticoagulants in patients who can take them.
Imaging, Technique, and the Details That Determine Outcomes
The left atrial appendage doesn’t look the same in every patient. Common anatomical patterns include chicken wing, windsock, cactus, and cauliflower shapes, and those differences can affect how an occlusion device fits and seals the appendage.
Before the procedure, cardiac CT or transesophageal echocardiography can help physicians measure the appendage opening, assess its depth, and understand the arrangement of its lobes. That information helps the operator select and size the appropriate device.
Imaging remains important during the procedure as well. Physicians use it to guide the transseptal puncture and confirm that the device has achieved an adequate seal before releasing it.
Patients also need follow-up after the procedure. Imaging performed roughly 45 days to a few months later can show whether a peridevice leak or device-related thrombus has developed. Those findings help physicians decide when and how to adjust the patient’s antithrombotic medications.
Many patients move from short-term anticoagulation or dual antiplatelet therapy to aspirin alone after the device has had time to become incorporated into the heart tissue. The exact regimen varies according to the device, the patient’s bleeding risk, and the physician’s assessment.
Experience also plays a role in procedural safety. Complications such as pericardial effusion, device embolization, and vascular access problems remain uncommon, but they can occur. Programs that perform LAAO regularly can draw on repeated experience with the procedure, its imaging requirements, and the anatomical variations that can make individual cases more difficult.
The Conversation Before the Catheter
For many patients, the most important part of LAAO happens before they enter the procedure room.
Patients can have the same stroke risk score and very different reasons for considering closure. Someone who has experienced a hemorrhagic stroke while taking a blood thinner may view the risks very differently from someone who has taken apixaban without complications for six years.
Physicians who regularly manage complex cardiovascular disease need to explain those differences in terms that patients can understand. Translating risk numbers into plain language can help patients understand what their individual numbers mean rather than simply hearing that one treatment is “better” than another.
The discussion should also cover what LAAO cannot do. Closing the appendage can reduce the risk of stroke caused by clots that form there, but it doesn’t treat atrial fibrillation itself. Patients may still need treatment for rate or rhythm control, and they may have other reasons to take antithrombotic medication, particularly if they also have coronary artery disease.
Patients should also know what to expect during the first months after closure. They’ll typically take an antithrombotic medication for a period after the procedure and undergo follow-up imaging. A small number of patients may develop residual leakage or device-related thrombus, which can require a longer course of medication and additional monitoring.
Where the Field Is Heading
Researchers continue to study several questions that could change how physicians use LAAO.
Trials including ALONE-AF and OCEAN are examining whether successful ablation can lower stroke risk enough for some patients to stop anticoagulation. If those studies produce positive results, they could influence which patients physicians consider for LAAO after ablation.
Device manufacturers are also developing newer designs that aim to reduce thrombus formation at the device and improve coverage of the appendage opening. Physicians are increasingly considering LAAO alongside other procedures, including ablation and certain structural heart interventions, when the patient’s anatomy and risk profile make that approach appropriate.
For now, Jaime Caballero, MD, takes a measured view of LAAO. Left atrial appendage occlusion has become an important option for patients whose bleeding risk makes long-term anticoagulation difficult or unsafe. It also offers a potential alternative for selected patients after ablation. The evidence supports careful patient selection rather than treating closure as the default approach for everyone with atrial fibrillation.
For patients in the Tampa area considering LAAO, the conversation starts with a practical question: has long-term anticoagulation become too risky or difficult to continue? A structural heart evaluation can then help determine whether closing the appendage offers a reasonable balance between stroke prevention, bleeding risk, and the patient’s quality of life.
