Left Atrial Appendage Occlusion: Data Update

Strategies for surface coatings of implantable cardiac medical devices

Cardiac medical devices (CMDs) are required when the patient's cardiac capacity or activity is compromised. To guarantee its correct functionality, the building materials in the development of CMDs must focus on several fundamental properties such as strength, stiffness, rigidity, corrosion resistance, etc. The challenge is more significant because CMDs are generally built with at least one metallic and one polymeric part. However, not only the properties of the materials need to be taken into consideration. The biocompatibility of the materials represents one of the major causes of the success of CMDs in the short and long term. Otherwise, the material will lead to several problems of hemocompatibility (e.g., protein adsorption, platelet aggregation, thrombus formation, bacterial infection, and finally, the rejection of the CMDs). To enhance the hemocompatibility of selected materials, surface modification represents a suitable solution. The surface modification involves the attachment of chemical compounds or bioactive compounds to the surface of the material. These coatings interact with the blood and avoid hemocompatibility and infection issues. This work reviews two main topics: 1) the materials employed in developing CMDs and their key characteristics, and 2) the surface modifications reported in the literature, clinical trials, and those that have reached the market. With the aim of providing to the research community, considerations regarding the choice of materials for CMDs, together with the advantages and disadvantages of the surface modifications and the limitations of the studies performed.

Long-term effect of anticoagulation following left atrial appendage occlusion with the LARIAT device in patients with nonvalvular atrial fibrillation: impact on thromboembolism, bleeding and mortality. Real life data

Introduction

Indications for left atrial appendage occlusion (LAAO) are varied and patients require individual management strategies. However, currently no guidelines exist for postprocedure oral anticoagulation (OAC) after an LAAO procedure.

Aim

To evaluate the effect of OAC on thromboembolism, bleeding and mortality following the LAAO procedure for patients with AF.

Material and methods

One hundred and thirty-nine consecutive patients with nonvalvular atrial fibrillation (NVAF) who underwent LAAO with the LARIAT device were followed for at least 40 months. Decisions about OAC and its modifications were individualized based on clinical presentation, patient and physician preferences.

Results

Following LAAO, 52 (41%) patients did not receive OAC (No-OAC group) and 75 (59%) patients received OAC (OAC group), without any intergroup differences in CHADS₂, CHA₂DS₂-VASc score or other thromboembolic risk factors. The median HAS-BLED score was higher in the OAC-group (median 3 (3-4) vs. 3 (2-4), p = 0.014). During a median follow-up time of 51 (43-57) vs. 55 (48-59) months in the No-OAC group and in the OAC group (p = 0.19) there were no significant differences between groups in ischemic stroke/TIA, 0 (0%) vs. 2 (2.7%), other thromboembolic events, 0 (0%) vs. 1 (1.3%), life-threatening, disabling or major events, 2 (3.7%) vs. 2 (2.7%), or annual mortality rate, 1.9% vs. 0.9%, respectively.

Conclusions

There is no need for OAC after the LAAO procedure. Omitting OAC after an LAAO procedure in AF patients: (1) has similar stroke prevention rates as patients on OAC, (2) has similar bleeding prevention rates as patients on OAC, (3) has similar safety endpoints and long-term efficacy as patients on OAC.