Valve morphology and timing of surgery in bicuspid aortic valve disease.

Background: The anatomy of bicuspid aortic valves (BAV) varies considerably and is broadly classified into two main types: two-sinus and fused BAV. Possible prognostic implications of these two main types remain unclear. This study aimed to assess potential associations between BAV morphology and the timing of surgery of the aortic valve or ascending aorta.

Methods: A multi-center cohort study including 1004 adult outpatients with BAV. BAV morphology was classified as either two-sinus or fused type. The primary outcome was a composite of surgical or endovascular intervention on the aortic valve or ascending aorta. The effect of morphology on the primary outcome was investigated using delayed-entry cause-specific Cox regression models using age as timescale.

Results: A total of 835 patients with fused BAV and 169 with two-sinus BAV were followed for 2044 person-years. Two-sinus BAV patients were younger (median age 47.2 vs. 53.6 years, p = 0.0002) with a higher prevalence of aortic coarctation (24% vs. 12%, p = 0.0003). The incidence rate of surgery was 9.3 per 100 person-years in fused BAV patients and 10.7 per 100 person-years in two-sinus BAV patients (difference [95%CI]: 1.42 [- 2.3, 5.1] per 100 person-years). Two-sinus morphology was associated with a higher age-related hazard of surgery compared to fused BAV (HR [95%CI]: 1.46 [1.02, 2.09]), a finding that remained significant after adjusting for sex.

Conclusion: Two-sinus BAV morphology was associated with a significantly higher age-related likelihood of requiring surgery on the aortic valve or ascending aorta.