Atrial fibrillation (AF) is nowadays the most common human arrhythmia and it is considered a marker of an increased risk of embolic stroke. It is known that 99% of AF-related thrombi are generated in the left atrial appendage (LAA), an anatomical structure located within the left atrium (LA). Left atrial appendage occlusion (LAAO) has become a good alternative for nonvalvular AF patients with contraindications to anticoagulants. However, there is a non-negligible number of device-related thrombus (DRT) events, created next to the device surface. In silico fluid simulations can be a powerful tool to better understand the relation between LA anatomy, haemodynamics, and the process of thrombus formation. Despite the increasing literature in LA fluid modelling, a consensus has not been reached yet in the community on the optimal modelling choices and boundary conditions for generating realistic simulations. In this line, we have performed a sensitivity analysis of several boundary conditions scenarios, varying inlet/outlet and LA wall movement configurations, using patient-specific imaging data of six LAAO patients (three of them with DRT at follow-up). Mesh and cardiac cycle convergence were also analysed. The boundary conditions scenario that better predicted DRT cases had echocardiography-based velocities at the mitral valve outlet, a generic pressure wave from an AF patient at the pulmonary vein inlets, and a dynamic mesh approach for LA wall deformation, emphasizing the need for patient-specific data for realistic simulations. The obtained promising results need to be further validated with larger cohorts, ideally with ground truth data, but they already offer unique insights on thrombogenic risk in the left atria.

Background: Transcatheter mitral valve repair (TMVR) is an effective therapy for high-risk patients with severe mitral regurgitation (MR) but heart failure (HF) readmissions and death remain substantial on mid-term follow-up. Recently, right ventricular (RV) to pulmonary arterial (PA) coupling has emerged as a relevant prognostic predictor in HF. In this study, we aimed to assess the prognostic value of tricuspid annular plane systolic excursion (TAPSE) to PA systolic pressure (PASP) ratio as a non-invasive measure of RV-to-PA coupling in patients undergoing TMVR with MitraClip (Abbott, CA, USA). Methods: Multicentre registry including 228 consecutive patients that underwent successful TMVR with MitraClip. The sample was divided in two groups according to TAPSE/PASP median value: 0.35. The primary combined endpoint encompassed HF readmissions and all-cause mortality. Results: Mean age was 72.5 ± 11.5 years and 154 (67.5%) patients were male. HF readmissions and all-cause mortality were more frequent in patients with TAPSE/PASP ≤ 0.35: Log-Rank 8.844, p = 0.003. On Cox regression, TAPSE/PASP emerged as a prognostic predictor of the primary combined endpoint, together with STS-Score. TAPSE/PASP was a better prognostic predictor than either TAPSE or PASP separately. Conclusions: TAPSE/PASP ratio appears as a novel prognostic predictor in patients undergoing MitraClip implantation that might improve risk stratification and candidate selection.

BACKGROUND: The optimal antithrombotic treatment after transcatheter left atrial appendage closure (LAAC) remains to be determined. The objective of this trial was to compare anticoagulation and antiplatelet therapy for preventing device-related thrombosis (DRT) after LAAC. METHODS: This was a prospective multicenter international randomized trial comparing 2 different antithrombotic strategies for preventing DRT after LAAC in patients with nonvalvular atrial fibrillation. Patients were randomized (1:1) to receive direct oral anticoagulants (DOACs) or dual antiplatelet therapy (DAPT; aspirin+clopidogrel) for 60 days. Patients underwent transesophageal echocardiography at 60 days, and the images were analyzed in a central echocardiography laboratory by experienced echocardiographers blinded to the allocated treatment. The primary outcome was DRT as determined by transesophageal echocardiography 60 days after LAAC in patients receiving the allocated treatment at the time of transesophageal echocardiography (per-protocol analysis). The safety outcome included all-cause mortality, stroke, bleeding, or site-reported DRT within 60 days after LAAC in all randomized patients (intention-to-treat analysis). RESULTS: A total of 510 patients (mean age 77±9 years, 35% women) were included between October 2018 and May 2025, and 253 and 257 patients were randomized to the DOAC and DAPT groups, respectively. Of these, 399 patients underwent transesophageal echocardiography and were receiving the allocated treatment at 60 days after LAAC. The primary outcome occurred in 3 patients (1.5%) in the DOAC group compared with 8 patients (4.1%) in the DAPT group (difference, −2.7% [95% CI, −6.0% to 0.6%]; P =0.110). The safety outcome occurred in 52 patients (22.5%) in the DOAC group compared with 82 patients (34.9%) in the DAPT group (difference, −12.4% [95% CI, −20.6% to −4.2%]; P =0.003), and differences were mainly driven by a lower rate of bleeding events in the DOAC group (44 patients [17.4%] versus 64 patients [24.9%]; difference, −7.5% [95% CI, −14.6% to −0.4%]; P =0.038). CONCLUSIONS: The use of DOACs after LAAC failed to reduce DRT compared with DAPT, but it was associated with an improved safety profile. The results of this study should be interpreted with caution because of statistical power issues related to the narrower-than-expected between-group differences and will need confirmation in future larger studies. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03568890.