Tanvi Ravi
Pronouns:
Research Mentor(s): Steven Bolling
Research Mentor School/College/Department: The Department of Cardiac Surgery / Medicine
Program: UROP
Session: Session 6 (3:40pm – 4:30pm)
Authors: Tanvi Ravi, China Green, Whitney Fu, Steven Bolling
Abstract
Objective: During cardiac surgery, surgeons may decide to close (or ligate) the left atrial appendage for patients with atrial fibrillation. Ligating the left atrial appendage is associated with reducing the risk of mortality and neurological events occurring in patients with atrial fibrillation. There is little research providing a definitive value to the success in reducing the risk of post-operative neurological events in patients with atrial fibrillation. Methods: This study pulls data from patients who underwent mitral valve surgery at Michigan Medicine who had preoperative atrial fibrillation. The patients were separated by whether they underwent a left atrial appendage ligation (LAAL) during their surgery or not. The charts of patients who underwent mitral valve surgery at Michigan Medicine between 2011-2022 were reviewed to extract certain variables. Patients were followed to see if they had a neurological event post-operatively. The possible neurological events included a cerebrovascular accident, transient ischemic attack, stroke, or reversible ischemic neurological deficit. A bivariable analysis of the data was used to determine the percent of patients with atrial fibrillation who experienced a neurological event, and to determine their postoperative survival. The Kaplan-Meier and Cox proportional-hazards model was employed to characterize patients’ long-term survival. Results: We analyzed 1352 patients with atrial fibrillation who underwent mitral valve surgery, 74 percent of these patients underwent a LAAL during their operation. There was no morbidity associated with LAA ligation. The median follow up for patients was 1.5 years. The incidence of stroke within LAA ligation was 2.8%, while the incidence of stroke in patients who did not undergo a LAAL was 2.5%. However, the one-year mortality amongst the LAAL group was 9.8%, which was significantly lower than the 18% one-year mortality amongst the no-LAAL group. The multivariable regression model revealed that LAAL was independently protective against one-year mortality. LAAL was associated with improved five-year survival. Through the Kaplan-Meier and Cox proportional-hazards model, LAAL was associated with better long-term survival as well. Conclusions: The results revealed that the incidence of strokes and mortality amongst patients with atrial fibrillation may be higher than previously reported. However, LAAL was independently protective against one-year mortality, and was associated with better long-term survival amongst patients with atrial fibrillation who underwent cardiac surgery. Cardiac surgeons should routinely elect to ligate the LAA in patients with a history of atrial fibrillation who are undergoing cardiac surgery.
