This will be a prospective, single-blinded, three-center, randomized, controlled trial comparing the effectiveness and safety of angioplasty guidewire-assisted transseptal puncture (GW-TSP) technique to transseptal left atrial (LA) access with conventional transseptal puncture with standard transseptal equipment (CON-TSP) in patients undergoing left atrial appendage occlusion (LAAO) procedure for atrial fibrillation. The targeted population will consist of patients with atrial fibrillation undergoing LAAO.

Transseptal catheterization is a critical step for left atrial interventions (atrial fibrillation ablation, LA appendage closure, mitral valve interventions). The availability of suitable tools and techniques is essential to safely perform the TSP, effectively deliver radiofrequency lesions, deploy LA devices, and anticipate difficult procedural situations in which complications may arise. Historically, a conventional Brockenbrough (BRK) needle has been used for this procedure to mechanically puncture the fossa ovalis, which has been well described in the literature. Although generally safe, serious complications such as perforation of the atrial wall or aorta can occur.

This study is intended to assess the safety, performance and usability of the angioplasty guidewire in facilitating access to the left atrium during LAAO procedures for the treatment of atrial fibrillation (AF). Moreover, the study will assess the impact of the GW-TSP on procedural times, including time to achieve left atrial accesses, total procedure times, total fluoroscopy time. The study is a prospective, single-blinded, three-center, randomized, controlled trial. Enrolled subjects who meet the study inclusion/exclusion criteria will be evaluated during the LAAO procedures and followed until release from hospital post procedure per institutional standard of care. After 30 days, patient will be contacted by telephone to obtain information on their clinical condition and any adverse events; if necessary, a clinic visit may be performed when required by the physician.

Inclusion Criteria:

• Patient is referred to receive a LAAO procedure for atrial fibrillation, requiring transseptal access and LA catheterization
• Patients greater than 18 years of age
• Patient has signed the informed consent form and is willing to participate in the clinical study and data collection

Exclusion Criteria:

• Previous left atrial (LA) ablation or LA surgery
• Active Intracardiac Thrombus
• Pre-existing pulmonary vein stenosis or PV stent
• Pre-existing hemidiaphragmatic paralysis
• Contraindication to anticoagulation or radiocontrast materials
• Cardiac valve prosthesis
• Myocardial infarction, PCI / PTCA, or coronary artery stenting during the 3-month period preceding the consent date
• Cardiac surgery during the three-month interval preceding the consent date
• Significant congenital heart defect (including atrial septal defects or PV abnormalities but not including PFO)
• Significant chronic kidney disease (CKD - eGFR <30 µMol/L)
• Uncontrolled hyperthyroidism
• Cerebral ischemic event (strokes or TIAs) during the six-month interval preceding the consent date
• Pregnancy
• Life expectancy less than one year
• Currently participating or anticipated to participate in any other clinical trial of a drug, device or biologic that has the potential to interfere with the results of this study
• Unwilling or unable to comply fully with study procedures and follow-up