Abstract
Background
Increasing evidence suggests that left atrial (LA) structural and functional changes have an important role in risk stratification and prediction of clinical outcomes. We know from multiple data that left atrial maximum volume (LAVI), measured at end-systole, is a powerful prognostic marker in multiple patient groups. However, recent studies have suggested that this marker may not be the best representative of diastolic function as it does not image the full spectrum of atrial mechanics. Another measure of LA function is the left atrial emptying fraction (LAEF), which has proved to be a significant prognostic marker in many patient groups. Less known is its role in event prediction in severe aortic stenosis patients, a disease with a very important burden in modern societies.
Purpose
The authors hypothesised that LAEF is a powerful predictor of clinical outcomes at 1 year in patients with severe aortic stenosis.
Methods
We retrospectively evaluated 151 patients referred to our echocardiography laboratory with the diagnosis of severe aortic stenosis. All patients underwent transthoracic echocardiography. LA maximum volume was indexed to body surface area. LAEF was calculated as LAVI-LA minimum volume divided by LAVI. Patients were followed for 1 year regarding clinical outcomes. Clinical outcome was defined as a composite of hospital admission for a cardiovascular (CV) cause, emergency department recurrence for a CV cause or CV death. Logistic binary regression was used to evaluate associations of LAEF with the outcome.
Results
A total of 51.7% of patients (n=78) were males. Mean patient age was 76.6±8.0 years. A total of 38.4% of patients were diabetics (n=56), 96% had dyslipidaemia (n=145) and 25% (n=37) had atrial fibrillation. Mean left ventricular ejection fraction (LVEF) was 60.6±7.3, and mean LAVI was 41.4±12.1. In a multivariable regression model including clinical and echocardiographic markers, higher LAVI and pulmonary artery systolic pressure (PASP) were associated with lower LAEF. Receiver operating characteristic curve analysis showed that the predictive value of LAEF for outcomes at 1 year was 0.693 (AUC=0.693, CI 95% 0.578–0.809, p=0.002), performing better than other echocardiographic markers such as LAVI (AUC=0.567, CI 95% 0.440–0.694, p=0.286), PASP (AUC=0.582, CI 95% 0.451–0.714, p=0.191) and LVEF (AUC=0.590, CI 95% 0.464–0.716, p=0.153). After adjustment of baseline characteristics, a LAEF less than 41.3% remained a good predictor of clinical outcomes at 1 year (OR 2.615, CI 95% 1.085–6.305, p=0.32).
Conclusions
In this cohort of severe aortic stenosis patients, a reduced LAEF was associated with greater incidence of cardiovascular events, being a stronger predictor than LAVI, PASP or LVEF. This study suggests that LA dysfunction over LA volumes correlates better with clinical outcomes.
Funding Acknowledgement
Type of funding source: None
49 Left atrial strain is a powerful predictor of pulmonary artery hypertension in patients with severe aortic stenosis
