Does Left Atrial Size Predict Mortality in Asymptomatic Patients with Severe Aortic Stenosis?

Background: We assessed the hypothesis that diastolic function represented by left atrial size determines the rate of development of symptoms and the risk of all-cause mortality in asymptomatic patients with severe aortic stenosis (AS). Methods: From a database of 622 asymptomatic patients with isolated severe AS (velocity by Doppler >= 4 m/sec) followed for 5.4 +/- 4 years, we reviewed the echocardiograms and evaluated Doppler echocardiographic indices of diastolic function. Prediction of symptom development and mortality by left atrial diameter with and without adjusting for clinical and echocardiographic parameters was performed using Cox proportional-hazards regression analysis. Results: The age was 71 +/- 11 years and 317 (62%) patients were males. The aortic valve mean gradient was 46 +/- 11 mmHg, and the Doppler-derived aortic valve area was 0.9 +/- 0.2 cm2. During follow-up, symptoms developed in 233 (45%), valve surgery was performed in 290 (57%) and 138 (27%) died. Left atrial enlargement was significantly correlated with symptom development (P < 0.05) but the association diminished after adjusting for aortic valve area and peak velocity (P = 0.2). However, atrial diameter predicted death independent of age and gender (P = 0.007), comorbid conditions (P = 0.03), and AS severity and Doppler parameters of diastolic function (P = 0.002). Conclusion: Diastolic function, represented as left atrial diameter, is related to mortality in asymptomatic patients with severe AS. (ECHOCARDIOGRAPHY 2010;27:105-109).