LAA occlusion appears today as a valid alternative to long-term oral anticoagulation (OAC) in selected patients with nonvalvular atrial fibrillation (AF) at high thromboembolism risk in case of relative or absolute contraindications to OAC.
In the first publication, we underlined the importance of multimodality imaging in the understanding of 3D aspects and anatomy of the left atrial appendage (LAA) and surrounding structures for LAA occlusion (LAAO) procedures. Performant imaging is essential for procedural planning, during each step of the procedure, and for device surveillance after implantation. With the use of multimodality imaging, including 2D/3D echocardiography, fluoroscopy, and cardiac computed tomography, the safety and efficacy of the procedure can be increased.
The second part of this dissertation aimed to analyze the incidence, risk factors, treatment and prognosis of device-associated thrombosis (DAT), which is a potential complication after LAAO. DAT appeared to be an infrequent complication of percutaneous LAAO, with an overall incidence of DAT estimated at 3.9%. It occurred mainly early after the procedure (median time from procedure to diagnosis: 1.5 months) and was associated with a low rate of neurological complications. In the majority of cases, diagnosis was made during follow- up imaging with transoesophageal echocardiography (TOE). The treatment consisted mostly of anticoagulation, either with low molecular weight heparin or with OAC and was highly effective with complete thrombus resolution achieved in 95% of cases. Further studies are needed to evaluate the optimal management of DAT.
The third goal of this work was to analyze the efficacy and safety of LAAO in the subgroup of patients with previous major gastrointestinal (GI) bleeding. We found that, in these patients, the overall procedural safety of LAAO with the Amplatzer Cardiac Plug was high, although it was associated with an increased risk of periprocedural major bleeding. The efficacy of LAAO for stroke reduction was high and similar in patients with or without previous major GI bleeding, with similar overall survival in both groups. During the total follow-up (FU) period (periprocedural period and from day 8 to the end of FU), the procedure was associated with a reduction in the rate of bleeding events compared to the expected rate based on the HAS-BLED score. However, as compared to patients without previous major GI bleeding, this diminution in bleeding risk was less pronounced in patients with previous MGIB, as more major bleeding events were observed in the periprocedural period.
Further trials are needed to assess the best use and indication of LAA occluders, evaluation of LAAO vs. non-vitamin K oral anticoagulants, evaluation of results in specific subgroups of patients, and evaluation of the optimal antithrombotic regimen after implantation. Team approach, multimodality imaging and patient-tailored management will likely have a key role in LAAO in the future.