Effect of bicuspid aortic valve phenotype on progression of aortic stenosis

Abstract

Aims: To compare the progression of aortic stenosis (AS) in patients with bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV).

Methods and results: One hundred and forty-one patients with mild-to-moderate AS, recruited prospectively in the PROGRESSA study, were included in this sub-analysis. Baseline clinical, Doppler echocardiography and multidetector computed tomography characteristics were compared between BAV (n = 32) and TAV (n = 109) patients. The 2-year haemodynamic [i.e. peak aortic jet velocity (Vpeak) and mean transvalvular gradient (MG)] and anatomic [i.e. aortic valve calcification density (AVCd) and aortic valve calcification density ratio (AVCd ratio)] progression of AS were compared between the two valve phenotypes. The 2-year progression rate of Vpeak was: 16 (-0 to 40) vs. 17 (3-35) cm/s, P = 0.95; of MG was: 1.8 (-0.7 to 5.8) vs. 2.6 (0.4-4.8) mmHg, P = 0.56; of AVCd was 32 (2-109) vs. 52 (25-85) AU/cm2, P = 0.15; and of AVCd ratio was: 0.08 (0.01-0.23) vs. 0.12 (0.06-0.18), P = 0.16 in patients with BAV vs. TAV. In univariable analyses, BAV was not associated with AS progression (all, P ≥ 0.26). However, with further adjustment for age, AS baseline severity, and several risk factors (i.e. sex, history of hypertension, creatinine level, diabetes, metabolic syndrome), BAV was independently associated with faster haemodynamic (Vpeak: β = 0.31, P = 0.02) and anatomic (AVCd: β = 0.26, P = 0.03 and AVCd ratio: β = 0.26, P = 0.03) progression of AS.

Conclusion: In patients with mild-to-moderate AS, patients with BAV have faster haemodynamic and anatomic progression of AS when compared to TAV patients with similar age and risk profile. This study highlights the importance and necessity to closely monitor patients with BAV and to adequately control and treat their risk factors.

Clinical trial registration: https://clinicaltrials.gov Unique identifier: NCT01679431.

Keywords: anatomic progression; aortic stenosis; aortic valve calcification; bicuspid aortic valve; haemodynamic progression; tricuspid aortic valve.

Figure 1

Two-year haemodynamic progression of aortic stenosis in patients with tricuspid aortic valve and bicuspid aortic valve. (A) Two-year peak aortic jet velocity (V_peak) progression. (B) Two-year MG progression. The box shows 25th and 75th percentiles, the median line shows the median value, error bars the 10th and 90th percentiles; circles are outliers. The numbers at the top of the graph are median (25th–75th percentiles).

Figure 2

Proportion and distribution of patients with a mild, moderate or severe aortic stenosis at baseline and 2-year follow-up according to haemodynamic severity (A) and proportion of patients progressing in aortic stenosis severity grade (from mild to moderate, mild to severe, or moderate to severe) from baseline to follow-up (B). The numbers in the boxes are number of patients in each group.

Figure 3

Two-year anatomic progression of aortic stenosis in patients with tricuspid aortic valve and bicuspid aortic valve. (A) Two-year AVCd progression. (B) Two-year AVCd ratio progression. The box shows 25th and 75th percentiles, the median line shows the median value, error bars the 10th and 90th percentiles; circles are outliers. The numbers at the top of the graph are median (25th–75th percentiles).

Figure 4

Proportion and distribution of patients with a non-severe or severe aortic stenosis at baseline and 2-year follow-up according to anatomic severity (A) and proportion of patients progressing from non-severe to severe aortic stenosis (from non-severe AVCd to severe AVCd) from baseline to follow-up (B). The numbers in the boxes are number of patients in each group.

Figure 5

Unadjusted (A) and adjusted (B) Kaplan–Meier curves censored at time of AVR or all-cause death according to aortic valve phenotype (BAV vs. TAV). ^aHR obtained by Cox multivariable analysis and adjusted for age, sex, hypertension, diabetes, and creatinine level.