Long-term outcomes of successful left atrial appendage occlusion with focus on stroke prevention: 10-year follow-up of a single-center registry.

Background: Percutaneous left atrial appendage occlusion (LAAO) is an alternative to anticoagulation in the prevention of stroke in patients with nonvalvular atrial fibrillation, especially in patients with a contraindication for oral anticoagulation therapy (OAT). Objective: The study sought to obtain long-term patient outcomes after successful LAAO in everyday clinical practice. Methods: In this single-center registry spanning over 10 years, data of all consecutive patients that underwent percutaneous LAAO were collected. Observed thromboembolic and major bleeding event rates after successful LAAO during follow-up were compared with expected event rates based on CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65-74 years, sex category) and HAS-BLED (hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol) scores. Furthermore, anticoagulation and antiplatelet use during follow-up was evaluated. Results: Of 230 patients scheduled for LAAO (38% women, 69.5 ± 8.2 years of age, CHA2DS2-VASc score 3.9 ± 1.6, HAS-BLED score 2.9 ± 1.0), 218 patients had a successful implantation (95%) with a follow-up duration of 5.2 ± 3.1 years. The procedure was combined with catheter ablation in 52% of the patients. Fifty thromboembolic complications (24 ischemic stroke, 26 transient ischemic attack) were observed during follow-up in 40 (18%) of 218 patients. Ischemic strokes occurred with a rate of 2.1 per 100 patient-years, accounting for a 66% relative risk reduction compared with the CHA2DS2-VASc predicted event rate. Device-related thrombus was observed in 5 (2%) patients. Sixty-five nonprocedural major bleeding complications occurred in 24 (11%) of 218 patients with a rate of 5.7 per 100-patient years, which is comparable to estimated HAS-BLED-bleeding rates under OAT use. At end of follow-up 71% of all patients were on single antiplatelet or no antiplatelet or anticoagulation treatment, while 29% were on OAT. Conclusion: Thromboembolic event rates during long-term follow-up after successful LAAO remained consistently lower than expected supporting the efficacy of LAAO.

COMPARE LAAO: Rationale and design of the randomized controlled trial "COMPARing Effectiveness and safety of Left Atrial Appendage Occlusion to standard of care for atrial fibrillation patients at high stroke risk and ineligible to use oral anticoagulation therapy".

BACKGROUND: Left atrial appendage occlusion (LAAO) provides an alternative to oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation (AF). In patients with a long-term or permanent contraindication for OAC randomized controlled trial (RCT) data is lacking. STUDY OBJECTIVES: To assess the efficacy and safety of LAAO in AF patients who are ineligible to use OAC. The co-primary efficacy endpoint is (1) time to first occurrence of stroke (ischemic, hemorrhagic, or undetermined) and (2) time to first occurrence of the composite of stroke, transient ischemic attack (TIA), and systemic embolism (SE). The primary safety endpoint is the 30-day rate of peri-procedural complications. STUDY DESIGN: This is a multicenter, investigator-initiated, open-label, blinded endpoint (PROBE), superiority-driven RCT. Patients with AF, a CHA2DS2-VASc score ≥2 for men and ≥3 for women and a long-term or permanent contraindication for OAC will be randomized in a 2:1 fashion to the device- or control arm. Patients in the device arm will undergo percutaneous LAAO and will receive post-procedural dual antiplatelet therapy (DAPT) per protocol, while those in the control arm will continue their current treatment consisting of no antithrombotic therapy or (D)APT as deemed appropriate by the primary responsible physician. In this endpoint-driven trial design, assuming a 50% lower stroke risk of LAAO compared to conservative treatment, 609 patients will be followed for a minimum of 1 and a maximum of 5 years. Cost-effectiveness and budget impact analyses will be performed to allow decision-making on reimbursement of LAAO for the target population in the Netherlands. SUMMARY: The COMPARE LAAO trial will investigate the clinical superiority in preventing thromboembolic events and cost-effectiveness of LAAO in AF patients with a high thromboembolic risk and a contraindication for OAC use. NCT TRIAL NUMBER: NCT04676880.

Hemostatic biomarkers and antithrombotic strategy in percutaneous left atrial interventions: State-of-the-art review.

Atrial septal defect, persistent foramen ovale and the left atrial appendage are nowadays often percutaneously closed with implantable devices. These interventions may be complicated by thromboembolic events and the perfect post-procedural antithrombotic management is still under investigation. The mechanisms leading to left atrial device-related thrombus and thromboembolic complications are not fully understood. Biomarkers of coagulation activation are elevated following percutaneous device placement, peaking within one month and returning to baseline values after three months. By contrast, platelet reactivity shows no post-procedural increase. This suggests that an optimal antithrombotic regimen should perhaps include (oral) anticoagulation therapy rather than the currently more frequently prescribed antiplatelet-based regimen. Furthermore, biomarkers of endothelial activation, fibrinolysis, and on-treatment platelet reactivity may be of value in predicting device-related thrombus and bleeding and guide future medical strategy, facilitating personalized medicine.