Causes of death and morbidity in patients with atrial fibrillation after left atrial appendage occlusion

Rehearsal simulation to determine the size of device for left atrial appendage occlusion using patient-specific 3D-printed phantoms

Left atrial appendage (LAA) occlusion (LAAO) is used to close the finger-like extension from the left atrium with occlusion devices to block the source of thrombosis. However, selection of the devices size is not easy due to various anatomical changes. The purpose of this study is patient-specific, computed tomography angiography (CTA)-based, three-dimensionally (3D) printed LAAO phantoms were applied pre-procedure to determine the size. Ten patients were enrolled prospectively in March 2019 and December 2020. The cardiac structure appearing in CTA was first segmented, and the left atrium and related structures in the LAAO procedure were modeled. The phantoms were fabricated using two methods of fused deposition modeling (FDM) and stereolithography (SLA) 3D printers with thermoplastic polyurethane (TPU) and flexible resin materials and evaluated by comparing their physical and material properties. The 3D-printed phantoms were directly used to confirm the shape of LAA, and to predict the device size for LAAO. In summary, the shore A hardness of TPU of FDM was about 80–85 shore A, and that of flexible resin of SLA was about 50–70 shore A. The measurement error between the STL model and 3D printing phantoms were 0.45 ± 0.37 mm (Bland–Altman, limits of agreement from − 1.8 to 1.6 mm). At the rehearsal, the estimations of device sizes were the exact same with those in the actual procedures of all 10 patients. In conclusion, simulation with a 3D-printed left atrium phantom could be used to predict the LAAO insertion device size accurately before the procedure.

Clinical follow-up of left atrial appendage occlusion in patients with atrial fibrillation ineligible of oral anticoagulation treatment-a systematic review and meta-analysis

PURPOSE

The recommended stroke prevention for patients with atrial fibrillation (AF) and increased risk of ischemic stroke is oral anticoagulation (OAC). Parts of the patient population are not eligible due to contraindication, and percutaneous left atrial occlusion (LAAO) can then be a preventive treatment option. The aim of this systematic review and meta-analysis is to estimate the long-term clinical effectiveness of LAAO as stroke prevention in patients with AF, increased risk of ischemic stroke, and contraindication to OAC.

METHODS

We performed a systematic review and meta-analysis, using Poisson random effect models, to estimate the incidence rate (events per 100 patient-years) of ischemic stroke, transient ischemic attack, major bleeding, and all-cause death after LAAO treatment. We also calculated the risk reduction of ischemic stroke with LAAO compared with no stroke prevention estimated through a predicted risk in an untreated population (5.5 per 100 patient-years).

RESULTS

We included 29 observational studies in our meta-analysis, including 7 951 individuals and 12 211 patient-years. The mean CHA2DS2-VASc score among the patients in the included studies is 4.32. The pooled incidence rate of ischemic stroke is 1.38 per 100 patient-years (95% CI 1.08; 1.77). According to a meta-regression model, the estimated incidence rate of ischemic stroke at CHA2DS2-VASc 4 is 1.39 per 100 patient-years. This implies a risk reduction of 74.7% with LAAO compared to predicated risk with no stroke prevention.

CONCLUSIONS

Our results suggest that LAAO is effective as stroke prevention for patients with AF, increased risk of stroke, and contraindication to oral anticoagulation.