Hemodynamic Progression of AS
Progression of hemodynamic parameters is shown in Table 2 . Median echocardiographic interval was 2.6 (IQR 1.6-4.2) years and was significantly longer in the BAV cohort (p=0.011). Despite longer echocardiographic follow-up, the proportion of BAV patients who had progressed beyond initial baseline severity was similar to TAV patients (56% and 55%, respectively, p=0.9). However, at latest follow-up, 22 (37%) BAV patients had developed severe AS compared to 50 (28%) TAV patients (p=0.062). Annualized progression rate was similar between groups, regardless of hemodynamic parameter used (Figure 1 ). Median annualized progression of mean gradient was 2.3 (IQR 0.6-5.0) mmHg/year for patients with TAV vs. 1.5 (IQR 0.5-4.1) mmHg/year for patients with BAV (p=0.5). Median annualized progression of peak velocity was 0.14 (IQR 0-0.31) m/s/year for patients with TAV vs. 0.10 (IQR 0.04-0.26) m/s/year in patients with BAV (p=0.4).
Patients were dichotomized into slow and rapid progressors based on the overall average annualized progression of mean gradient of 2.85 ± 5.31 mmHg/year. The proportion of rapid progressors was similar between cohorts, with 74 (43%) rapid progressors in the TAV group and 21 (36%) in the BAV group (p=0.4), Table 2 .