Feasibility and Safety of Atrial Biopsy　- Evidence From 1,000 Cases

Atrial biopsy is technically challenging owing to the atria's thin walls and relatively thick endocardium. This study assessed the feasibility and safety of echocardiography-guided atrial biopsy in a consecutive cohort of 1,000 patients who underwent catheter ablation for atrial tachyarrhythmias or percutaneous left atrial (LA) appendage occlusion.

Atrial biopsy was performed at the limbus of the fossa ovalis through the femoral vein using a 5.5-Fr (n=233) or a 7.0-Fr (n=767) bioptome under intracardiac (n=963) or transesophageal (n=37) echocardiography guidance, alongside fluoroscopy. For histological analysis, 5 tissue samples were collected from the same site. Biopsy was successfully completed in 996 (99.6%) patients. Patients were divided based on histological depth into Group A (biopsy beyond the endocardium; n=885) and Group B (endocardial-only biopsy; n=111). Multivariable logistic regression identified larger LA volume, use of a 5.5-Fr bioptome, and amyloid deposition as independent predictors of Group B (P=0.009, P<0.001, and P=0.001, respectively). Moreover, biopsy-related complications were unrecorded.

Echocardiography-guided atrial biopsy is a feasible and safe technique. However, atrial enlargement, smaller bioptome size, and amyloid deposition are associated with unsuccessful endocardial penetration and collection of myocardial tissue.