RESECTION OF THE ATRIAL APPENDAGES AND ITS IMPACT IN THE NATRIURETIC HOMEOSTASIS: DEVELOPMENT AND VALIDATION OF AN ANIMAL MODEL IN AN ACADEMIC MEDICAL CENTER.

Background: The left atrial appendage (LAAp) resection is an effective treatment approach to reduce the risk of thromboembolism in patients with atrial fibrillation. Objective: To study was to study the impact of removing atrial appendages in the production of natriuretic peptides (NPs) in conditions of volume overload and to develop an experimental model of LAAp resection. Materials and Methods: In a swine model of ischemic heart failure (HF), serum NP levels were measured before (Basal-1A) and after (Basal-1B) a fluid overload. Animals were grouped as follows: (0) preserved appendages, (1) resected LAAp, and (2) both atrial appendages resected. Levels of NP were measured before (2A) and after a fluid overload (2B). Results: Furin levels were higher in Group 0-2A than in Group 2-2A, and a significant increase was found in Group 0-2B compared to Groups 1-2B and 2-2B. Corin levels increased in Basal-1B versus Basal-1A. Atrial NP (ANP) decreased in Basal-1B compared to Basal-1A. After HF induction, ANP increased in Groups 2-2A and 2-2B. Conclusions: Resection of atrial appendages drastically modifies the natriuretic mechanisms of cardiac homeostasis, especially after a fluid overload challenge. Herein, we describe the face and predictive validation of an animal model of atrial appendage resection useful to investigations in translational medicine.