digging around this article I would suggest that where they say
... The life expectancy of individuals with asymptomatic BAV who are identified in the community is excellent and similar to that of the general population.
7 8 However, patients who undergo surgical aortic valve replacement (AVR) have a life expectancy that is approximately 2 years shorter than that of the general population.
9 Furthermore, the prognosis of patients with BAV versus the general population after aortic valve surgery remains to be determined.
that this is related to the very small number of complications that arise from surgery, discounting those issues I would not be surprised to find that its "similar to that of the general population" (and what the fcuk is 1.9 years if not similar)
points to note:
The mean follow-up period was 6.3 years (maximum 13.3 years)
not much really, not even lenghty with many studies follwing up 10 years (and the study I was involved in 29 years).
ultimately they say themselves:
Conclusions The survival of patients with BAV following aortic valve surgery was excellent and similar to that of the general population.