Abstract 17207: Prognostic Value of Valvuloarterial Impedance in Calcific Aortic Stenosis

Abstract

Background: Although valvuloarterial impedance (Z_VA) is a promising parameter representing global left ventricular (LV) afterload in calcific aortic stenosis (AS), its prognostic significance needs to be tested in different patient population.

Methods: A total of 480 consecutive patients (230 men, age 66±11 years) with severe AS (indexed aortic valve area≤0.6 cm²/m²) and preserved left ventricular (LV) ejection fraction (≥50%) was included. Patients were divided into 2 groups using arbitrary cut-off values of mean pressure gradient (PG of 40 mmHg) and Z_VA (4.0 mmHg/mL/m²).

Results: Mean (±SD) of Z_VA and PG were 3.7±0.8 mmHg/mL/m² and 61.2±20.3 mmHg, respectively. Sixty seven patients (14%) were classified to have low PG and 161 (34%) to have high Z_VA. During a median follow-up of 719 days, 322 patients (67%) underwent aortic valve replacement and 34 (7%) died. Age (hazard ratio [HR], 1.07; 95% CI, 1.02-1.10; P=0.002), serum creatinine level (HR, 1.32; 95% CI, 1.13-1.54; P=0.001) and AVR (HR, 0.17; 95% CI, 0.08-0.36; P<0.001) were independently associated with mortality. Survival rate after AVR was different according to pre-AVR Z_VA value and this tendency was present even in patients who did not undergo AVR. PG did not show any prognostic value (figure).

Conclusions: Our population was characterized by low mean Z_VA and low prevalence of low PG group. Z_VA appears to be an adjunctive prognosticator.