0556: Left atrial strain is a powerful predictor of pulmonary hypertension in patients with severe aortic stenosis

Background Pulmonary hypertension (PH) is one of the most powerful predictors of outcome in patients with severe aortic stenosis (AS). However, the mechanisms of PH occurring in the setting of AS are not fully understood. Methods We studied 60 consecutive AS patients referred for preoperative assessment. Echocardiographic measurement: left ventricular ejection fraction (LVEF), mass (iLVM), longitudinal systolic strain (LVS), mean aortic gradient (MAG), aortic valve area (AVA), mitral E/A and E/e’ ratios, TAPSE, tricuspid annulus S wave velocity, left atrial volume (iLAV), left atrial longitudinal end systolic strain using speckle tracking (LAS). Right heart catheterization (RHC) measurements: pulmonary artery pressures (s/d/mPAP), pulmonary capillary wedge pressure (PCWP). Results Patient age was 81±8 years. MAG was 45±16mmHg, AVA 0.74±0.2cm 2 , LVEF 63±16% (range 24-87), LVS –16±4%, LAS-4C 17±8% and LAS-2C 18±9%. Intraobserver variability for LAS measurement was 6%, interobserver variability was 7%. RHC showed: sPAP 51±18mmHg (range 28-101), mPAP 32±11mmHg (range 15-60), PCWP 19±8mmHg. In univariate analysis, the following echo-cardiographic parameters were associated with pulmonary artery pressures: LVS, mitral E/A and E/e’ ratios, mitral E wave deceleration time, TAPSE, tricuspid regurgitant flow velocity (feasibility 72%), LAS 4-C (feasibility 100%), and LAS 2-C (feasibility 94%). In multivariate analysis, except for the tricuspid regurgitant velocity, only LAS was independently associated with sPAP (r=–0.68, p 55mmHg) with a sensitivity of 85% and a specificity of 78%. Conclusion LAS measured by speckle tracking analysis is a simple and reproducible parameter and is a strong predictor of PH in patients with severe AS. These results suggest the LA reservoir function is a critical determinant of sPAP in AS. The prognostic value of LA strain should be further assessed.