There are limited data to describe the relationship between the transvalvular gradient and mortality among patients who undergo aortic valve replacement.Using the National Echo Database Australia, valvular hemodynamics were characterized in 3,943 men (mean age, 62 ± 18 years) and 2,107 women (mean age, 62 ± 19 years) who underwent aortic valve replacement (median follow-up duration, 770 days; interquartile range, 381-1,584 days). The degree of impaired valvular hemodynamics (IVH) was categorized as mild (mean gradient 10.0-19.9 mm Hg, peak velocity 2.0-2.9 m/sec), moderate (mean gradient 20.0-39.9 mm Hg, peak velocity 3.0-3.9 m/sec), or severe (mean gradient ≥ 40.0 mm Hg, peak velocity ≥ 4 m/sec or effective orifice area < 0.8 cm).2Overall, 2,175 (36.0%), 2,598 (42.9%), 698 (11.5%), and 579 (9.6%) patients had no, mild, moderate, and severe IVH, respectively. Those with residual moderate or severe IVH had 5-year mortality of 45.5% and 57.3%, respectively, and higher adjusted long-term all-cause mortality (adjusted hazard ratios, 1.44 and 2.02; P < .001) compared with "no IVH." Patients with mild IVH had similar mortality rates to those without IVH. A mortality threshold was evident above a mean transvalvular gradient >22.5 mm Hg after adjusting for age, sex, stroke volume index, aortic regurgitation, and effective orifice area.After aortic valve replacement, most patients displayed an acceptable aortic valve hemodynamic profile. Moderate to severe IVH, however, was associated with poor long-term survival, with a threshold for increased mortality similar to that of native valvular aortic stenosis evident.