A computational model predicted the final size of implanted WATCHMAN FLX devices in 72.7% of patients undergoing left atrial appendage closure (LAAC) in a small, single-center, observational study, new results show. Lauren S. Ranard, MD, of NewYork-Presbyterian Hospital, Columbia University Irving Medical Center, and colleagues, reported these findings in a manuscript published Wednesday online in JACC: Advances. LAAC is an approved alternative treatment for patients with nonvalvular atrial fibrillation who are at high risk for stroke and cannot tolerate oral anticoagulation. The procedure is safe, but it does not always result in complete closure. This can lead to peri-device leak, which is believed to increase the risk of thromboembolic complications. The anatomy of LAAs varies greatly, creating another procedural challenge. Therefore, clinicians assess three-dimensional LAA anatomy using both cardiac computed tomography angiography (CCTA) and transesophageal echocardiography (TEE). CCTA is being increasingly used in preprocedural planning of LAAC because it allows for the generation of patient-specific computational models. The FEops HEARTguide platform (FEops NV) is cloud-based and uses digital replicas of the patient’s heart to aid in procedural planning and device sizing. The U.S. Food and Drug Administration approved use of the platform The authors conducted the study to evaluate how accurately the platform predicted the size, position and compression of the implanted WATCHMAN FLX LAAC device (Boston Scientific) as compared to the intraprocedural TEE’s determination of the device characteristics. The study authors anonymized 25 preprocedural CCTAs and uploaded them to the FEops HEARTguide platform, which was blinded to the final implantation result. Three of the CCTAs did not have sufficient quality for computational modeling, so the study reported the results of 22 patients’ CCTAs. The patients’ mean age was 74.2 ± 8.8 years, and 81.8% (n=18) were male. The mean CHA2DS2-VASc score was 4.3 ± 1.9, and the mean HAS-BLED score was 4.0 ± 1.1. The most common comorbidities were hypertension (100%), chronic kidney disease (68.2%) and coronary artery disease (63.6%), and 15 patients (68.2%) had a prior bleeding event. The platform’s blinded analysis simulated the WATCHMAN FLX device size in 16 patients (72.7%). Of these, the model showed a simulated device position comparable to that of the postoperative CCTA scan in 13 (81.3%) patients. The 3D-TEE measurements of these patients did not significantly differ from those predicted by the FEops model (Pearson correlation coefficient [r] ≥ 0.90). In the remaining six patients, for whom the model did not predict the implanted device size, operators chose a larger-sized WATCHMAN FLX per operator preference. Ranard and colleagues said that the FEops model might be improved if it were further trained using postprocedural CCTA and comparisons with 3D-TEE. They added that after they carefully reviewed the six cases in which the model did not predict an implanted device size, they “believe that the FEops HEARTguide platform-predicted device size could have been used to achieve successful LAAC in all cases.” The authors concluded that this is the first study to demonstrate that the FEops HEARTguide platform accurately predicts the implantation characteristics of the WATCHMAN FLX device. They added that future studies will be needed to determine whether computational modeling can accurately predict device implantation characteristics without reducing technical procedural success. In an accompanying editorial, Kasper Korsholm, MD, PhD, and Jens Erik Nielsen-Kudsk, MD, DMSc, both of Aarhus University Hospital, Denmark, pointed out Ranard and colleagues’ statement that further review of the cases showed that all could have successfully undergone LAAC with the model “highlights a key limitation to the study; the lack of a gold standard to compare the results against.” The commenters added that study showed that the rate of the FEops model’s disagreement with the actual implant result concerning the size and position of WATCHMAN FLX devices (n=9, 41%) is “not particularly” accurate, but neither does it necessarily mean that the model is “poor at predicting the optimal [LAAC] result.” Korsholm and Nielsen-Kudsk added that the prospective PREDICT-LAA trial is enrolling patients planned to undergo LAAC with Abbott’s Amplatzer Amulet device and will evaluate the impact of the FEops model on the primary outcome of incomplete LAAC and device-related thrombosis as assessed by 3-month cardiac CT. Sources: Ranard LS, Vahl TP, Sommer R, et al. FEops HEARTguide Patient-Specific Computational Simulations for WATCHMAN FLX Left Atrial Appendage Closure: A Retrospective Study. JACC Adv. 2022 Nov 30 (Article in press). Korsholm K, Nielsen-Kudsk JE. The Art of Planning a Left Atrial Appendage Closure: Will Computational Modeling Simplify the Intervention? JACC Adv. 2022 Nov 30 (Article in press). Image Credit: Who is Danny – stock.adobe.com