Abstract 13679: Prognostic Implication of Valvuloarterial Impedance in Patients Who Underwent Aortic Valve Replacement: Heterogeneity According to Underlying Etiology

Background: The valvuloarterial impedance (Z va ) has been introduced to represent global left ventricular (LV) afterload in aortic stenosis (AS). We sought to evaluate prognostic significance of Z va after aortic valve replacement (AVR) and to test whether underlying AS etiology is associated with prognostic implication of Z va . Methods: From 2007 to 2010, a total of 340 consecutive patients (167 men, age 65±10 years) with severe AS (indexed aortic valve area [AVA] ≤ 0.6 cm 2 /m 2 ) and preserved LV ejection fraction (LVEF ≥ 50%) who underwent AVR were recruited. The Z va was calculated as: ([systolic arterial pressure + mean pressure gradient]/indexed stroke volume) mmHg/mL/m 2 . The primary parameter of interest was overall mortality. Results: Tricuspid degenerative AS was present in 166 patients (Group 1, 49%), whereas bicuspid AS in 174 (Group 2, 51%). Group 1 was characterized by higher mean age (70±8 vs. 61±10 years, P 2 /m 2 , P = 0.230), and Z va (3.7±0.8 vs. 3.8±0.8 mmHg/mL/m 2 , P = 0.261). During follow-up (median 1,376 days, IQR 1,016 - 1,862), there were 34 (10%) cases of overall mortality including 3 (1%) cases of operative mortality. In all patients, age (HR, 1.064; 95% CI, 1.022 - 1.107; P = 0.002), diabetes (HR, 2.150; 95% CI, 1.048 - 4.409; P = 0.037) and Z va (HR, 1.609; 95% CI, 1.099 - 2.356; P = 0.015) were independent factors associated with mortality. In survival comparison according to median Z va (3.6 mmHg/mL/m 2 ), patients with high Z va presented significantly lower survival rate which was evident in Group 1 only, not in Group 2 (Figure). Conclusions: Z va is associated with survival after AVR in patients with severe AS and its prognostic implication is different according underlying etiology.