Right Ventricular Function Is Associated with Left Ventricular Stroke Volume in Patients with Severe Aortic Stenosis and Preserved Ejection Fraction.

Abstract

A subset of patients with severe aortic stenosis (AS) have lower stroke volumes and valve gradients despite a normal left ventricular ejection fraction (LVEF), referred to as paradoxical low-flow AS (PLF AS). However, the role of right ventricular (RV) function in patients with severe AS and preserved LVEF is not known. We hypothesized that right ventricular function is associated with left ventricular stroke volume in patients with severe AS and preserved LVEF. From an echocardiographic database, we retrospectively identified 102 patients with an indexed aortic valve area ≤0.6cm(2) /m(2) and LVEF≥50%. We used univariate and multivariate linear regression analysis to assess the association between aortic valve stroke volume index (SVi) and right ventricular systolic function as measured by tricuspid annular plane systolic excursion (TAPSE) and by right ventricular fractional area change (FAC). Our population was 98% male with mean age 77.4±9.3years and mean SVi of 36.1±7.9 mL/m(2) . Forty-four patients (43%) met criteria for PLF AS. TAPSE and FAC were positively associated with SVi in both univariate and multivariate regression analysis after correcting for left ventricular variables (β coefficient - TAPSE (cm): 4.59±1.3, P=0.001; FAC (%): 0.19±0.08, P=0.014). Additionally, PLF AS patients had significantly lower mean TAPSE and lower mean FAC when compared dichotomously to normal flow AS patients (P<0.05). Right ventricular systolic function assessed by TAPSE and FAC is significantly related to aortic valve flow in patients with severe AS and preserved LVEF.