Figure 13: Bar graph depicting maximum peak instantaneous Doppler gradients prior to (Pre) and one day after (Post) balloon aortic valvuloplasty and at intermediate-term (ITFU) and late (LTFU) follow-up. There was significant reduction (p< 0.001) after valvuloplasty which remained essentially unchanged (p > 0.1) at ITFU (12 ± 5 mo) and LTFU (3 to 9 years [mean 6 years]). Doppler-derived maximum peak instantaneous gradients at followup continue to be lower (p < 0.001) than pre-valvuloplasty gradients. SD, standard deviation.