Longitudinal Assessment of Left Atrial Remodeling in Patients With Chronic Severe Aortic Regurgitation

Background: There are significant sex and age differences in left ventricular (LV) remodeling that may lead to disparity in outcomes when used to inform the timing of aortic regurgitation (AR) intervention. Objectives: The aim of this study was to examine whether left atrial (LA) parameters might represent better criteria than LV parameters to inform the timing of AR intervention. Methods: Using data on patients with moderate to severe or severe AR with serial echocardiography (2010-2016), the longitudinal trends in left atrial volume index (LAVI) and left atrial reservoir strain (LAr) were evaluated by sex and age. The incremental utility of these parameters in predicting adverse events over LV parameters was also determined. Results: In 525 patients (25.7% women) with 1,687 echocardiograms over a median follow-up period of 2.0 years (Q1-Q3: 1.0-3.6 years), there was significant increase in LAVI (1.0 mL/m(2) per year [95% CI: 0.76-1.2 mL/m(2) per year]) and decrease in LAr (-1.3% per year [95% CI: -1.6% to -0.92%]), without a significant interaction by sex or age category (P for interaction >= 0.17). In addition, both LAVI and LAr were significant predictors of adverse events independent of LV parameters. The optimal discriminatory thresholds were 37 mL/m(2) for LAVI and 35% for LAr. These thresholds were similar across categories of sex and age. Within the relatively short-term follow-up, surgery was associated with survival benefit among patients with LAVI >= 37 mL/m(2) (HR: 0.33 [95% CI: 0.15-0.72]; P = 0.006) but was not statistically significant among patients with LAVI <37 mL/m(2) (HR: 0.46 [95% CI: 0.18-1.17]; P = 0.09). Similarly, surgery was associated with survival for the subgroup with LAr <= 35% but not among those with LAr >35%. Conclusions: Unlike LV remodeling, LA remodeling demonstrates a similar rate of progression between categories of sex and age among patients with AR. In addition, LA parameters provide incremental prognostic value over LV parameters.