In recent decades, the incidence of atrial fibrillation (AF) has increased exponentially worldwide.^1,2 This comorbidity is directly related to cardioembolic events, and oral anticoagulation is considered the gold standard treatment for its prevention. Although oral anticoagulation is effective in preventing ischemic stroke, warfarin is contraindicated in 14% to 44% of patients at risk for cardioembolic stroke; nevertheless, even in eligible patients, only 54% are anticoagulated. Currently, direct-acting oral anticoagulants (DOAC) are preferable as preventive therapy for ischemic stroke; however, the discontinuation rates of these drugs reported in clinical trials, mainly due to intolerance or side effects, vary from 23% to 35%. In patients with a history of hemorrhagic stroke, uncontrolled non-intracranial bleeding, and end-stage chronic kidney disease or dialysis, the use of DOAC is relatively or absolutely contraindicated.

In cases of non-valvular AF, when the aforementioned contraindications to DOAC use are present, left atrial appendage occlusion (LAAO) has shown to be effective as a therapeutic alternative.³ This procedure has been guided and performed using transesophageal echocardiography, which is considered the gold standard. However, services that have incorporated intracardiac echocardiography as an auxiliary tool during catheter ablation for the treatment of AF went on to use this method as a safe and effective alternative to transesophageal echocardiography in LAAO procedures.^3-5

In patients with non-valvular AF, ischemic stroke, in addition to being a feared complication with catastrophic consequences, can be prevented with the use of DOAC. Nonetheless, there are patients who have limitations to the DOAC, as well as patients who, even when using them, have cardioembolic events. For these reasons, LAAO has become an efficient mechanical alternative for preventing ischemic stroke.

Currently, transesophageal echocardiography and fluoroscopy are frequently used to guide LAAO. The main advantage of intracardiac echocardiography-guided LAAO would be avoiding general anesthesia in cases where this procedure is performed alone, in addition to being performed by the interventionist, keeping in mind that it is widely used in AF ablations. Even though the images produced by intracardiac echocardiography have excellent quality and clarity, in some cases, the evaluation of some structures may be limited, especially in enlarged left atria, as in patients with AF. This imaging limitation can generally be overcome by placing the intracardiac echocardiography catheter directly into the left atrium, which is not a limitation, considering that transseptal puncture is a step in this procedure.

The intracardiac echocardiography probe in the left superior pulmonary vein provides a long-axis view of the LAA that is similar to the 0° view on transesophageal echocardiography. With the probe 1 cm proximal to the ostium of the left pulmonary veins, tilted posteriorly (also called retroflexion), a view similar to 45° on transesophageal echocardiography can be obtained, showing the left superior pulmonary vein, the ostium of the LAA, the circumflex artery, and the mitral valve. This view, known as “home view,” is preferred during the procedure (Figures 2 and 3). Another important projection is known as “supramitral” (or inferior) view of the LAA similar to the 135° view on transesophageal echocardiography.⁶

Available clinical studies have shown that intracardiac echocardiography-guided LAAO appears to be non-inferior to transesophageal echocardiography in terms of procedural success, periprocedural complications, and embolic events.^6,7 A recent meta-analysis, which did not include any prospective randomized studies, with more than 1000 patients analyzed, confirmed that the success rates of the procedures are similar, with a tendency toward a lower rate of procedure-related complications and a lower contrast volume used in patients who received intracardiac echocardiography-guided LAAO compared to transesophageal echocardiography.⁷ Given that intracardiac echocardiography is a monoplanar imaging technique, we recommend that, prior to the procedure, transesophageal echocardiography or computed tomography angiography of the left atrium and LAA should be performed to rule out the presence of thrombi and to obtain adequate measurement of these structures that will be used to guide the intervention.

In summary, intracardiac echocardiography-guided LAAO shows results and follow-up similar to transesophageal echocardiography. Due to the large volume of LAAO procedures worldwide, new techniques to better integrate this procedure into the standard laboratory routine are important. Intracardiac echocardiography guidance simplifies the procedure in many cases, avoiding general anesthesia, reducing patient discomfort, and improving and optimizing room usage time. Taken together, the results of several observational studies support the adoption of intracardiac echocardiography-guided LAAO; nonetheless, operators need to master the technique by going through the learning curve necessary to improve and use this complex technique. Our initial experience with use of intracardiac echocardiography as a guide in this procedure was positive, obtaining initial success in all cases, without major acute complications during the procedure or subsequent months. We believe that this is a technique that can be adopted as an option for transesophageal echocardiography in centers with experienced operators.