Surgery promotes early postoperative changes in left atrial volume and function in non-ischemic symptomatic mitral regurgitation: a three-dimensional echocardiography study

Abstract

Background: Left Atrial (LA) dilation is associated with a worse prognosis in various clinical situations, including chronic Non-Ischemic Mitral Regurgitation (NIMR). Real time Three-Dimensional Echocardiography (3DE) has allowed a better assessment of LA volume and function. Although LA reverse remodeling has been observed in long-term outcome after surgery in NIMR, little is known about the behavior of LA structure and function in an early post-operative period. We aimed to analyze these aspects with 3DE. Methods: We prospectively studied 43 patients with symptomatic chronic NIMR who underwent valve repair or bioprosthetic valve replacement. LA volumes and function were analyzed before and 30 days after surgery by means of 3DE in all patients, and in a control group of 20 healthy subjects. We studied maximum, minimum and pre-atrial contraction volumes, and calculated total, passive and active LA emptying fractions. Results: Before surgery patients had higher LA volumes (p<0.001), but smaller LA emptying fractions than controls (p<0.01). After surgery, all three LA volumes reduced in both groups. Postoperative increase in active LA emptying fraction also occurred in both groups. Independent predictors of early postoperative LA reverse remodeling were diastolic blood pressure before surgery (Coefficient= - 0.004; p= 0.02), lateral mitral annulus early diastolic velocity (e') (Coefficient=0.02; p=0.008), and a mean transmitral diastolic gradient increment (Coefficient= - 0.035; p < 0.001), but not the surgical technique. Besides, e' was the only variable independently associated with the early recovery of active LA emptying fraction (OR= 1.664, P=0.027). Conclusion: LA reverse remodeling and functional improvement occur soon after surgery of symptomatic chronic NIMR patients, regardless of the surgical technique. Those changes are related to preoperative diastolic blood pressure and an echocardiographic marker of left ventricular diastolic function.