With interest rates still low and the market for variable annuities slumping fast it’s hard to be cheerful about the immediate future of annuities — except when it comes to structured VAs. And what a bright shining light structured VAs have been for the handful of insurers who sell the most of them. Allianz Life Insurance of North America sold $1.45 billion worth of structured VAs last year, compared with $592 million for traditional VAs. It marked the first time the former version came out on top, the company said.