Noninvasive assessment of filling pressure and left atrial pressure overload in severe aortic valve stenosis: Relation to ventricular remodeling and clinical outcome after aortic valve replacement

Abstract

One of the hemodynamic consequences of aortic valve stenosis is pressure overload leading to left atrial dilatation. Left atrial size is a known risk factor providing prognostic information in several cardiac conditions. It is not known if this is also the case in patients with aortic valve stenosis after aortic valve replacement. A total of 119 patients with severe aortic valve stenosis scheduled for aortic valve replacement were evaluated preoperatively and divided into 2 groups according to left atrial volume index (≥40 mL/m(2)). Echocardiography was repeated 12 months after surgery. Patients were followed up for 24 months. The primary end point was the composite end point overall mortality and hospitalization due to congestive heart failure. Preoperative left atrial dilation was associated with left ventricular hypertrophy and increased filling pressure. Preoperative left atrial volume index was associated with persistent abnormalities in left ventricular filling pressure and left ventricular mass index at 1 year after surgery. Event-free survival in patients with left atrial volume index of 40 mL/m(2) or more at 1 year was 71% compared with 88% in patients with left atrial volume index less than 40 mL/m(2) (P = .002). Patients with preoperative increased E/e' ratio and left ventricular hypertrophy were at increased risk. In Cox regression analysis after correcting for standard risk factors, left atrial volume index was found to be the only significant predictor of the composite end point. In a forward conditional multivariable model, left atrial volume index 40 mL/m(2) or greater (hazard ratio, 4.2 [1.6-10.7]; P = .003) remained an independent predictor, whereas E/e' was borderline significant (P = .06). In patients with symptomatic severe aortic valve stenosis undergoing aortic valve replacement, left atrial volume provides important prognostic information beyond standard risk factors.