LEFT ATRIAL STRAIN IS HIGHLY PREDICTIVE OF PULMONARY ARTERY PRESSURES IN PATIENTS WITH AORTIC STENOSIS

Background. Pulmonary hypertension is one of the most powerful predictors of outcome in patients with severe aortic stenosis (AS). The mechanisms of PH occurring in the setting of AS, however, are not fully understood.
Methods. We studied 30 consecutive AS patients referred for preoperative assessment. Echocardiographic assessment included left ventricular ejection fraction (LVEF) and mass (iLVM), mean aortic gradient (MAG), aortic valve area (AVA), mean E/E’ ratio at the mitral annulus, TAPSE, indexed left atrial volume (iLAV), and left atrial longitudinal end systolic 2D strain using speckle tracking in the apical 4 (LAS-4C) and 2-chamber (LA-2C) views. All patients underwent right heart catheterization (RHC) with measurement of pulmonary artery pressures (systolic: sPAP, mean: mPAP) and pulmonary capillary wedge pressure (PCWP).
Results. Patient age was 81 ± 8.8 years. MAG was 45 ± 16 mmHg, AVA was 78 ±.18 cm². Echocardiographic analysis yielded 63±16% (range 24-87) for LVEF, 151±45 g for iLVM, 18±8 for E/E’ ratio, 55±36 for iLAV, 20±6 mm for TAPSE, 16±7% for LAS-4C and 17±8% for LAS-2C. Feasibility was 100% for LAS-4C and 93% for LAS-2C. RHC showed: sPAP 51 ± 18 mmHg (range 28-101), mPAP 32 ± 11 mmHg (range 15-60), PCWP 19 ± 8 mmHg. sPAP correlated poorly with TAPSE and E/E', marginally with LVEF and MAG, and strongly with LAS-4C and LAS-2C (r = .72, 95% CI -2.5_-1.1, p<0.001).
Conclusion. Left atrial strain measured by speckle tracking analysis is a simple parameter to acquire and is a strong predictor of pulmonary artery pressure in patients with severe AS. These results suggest that the increase in sPAP is tightly linked to the decrease in left atrial reservoir function. The prognostic value of LA strain should be further assessed.