If you remove sapience from this situation, then blood pressure just is, period. One particular aspect of what is just one big chemical reaction, or [insert whatever is at the bottom of how reality works].
It is said that since god died, the meaning of life is what we make it to be. But if there's no one around capable of processing the concept of meaning, then life has no meaning at all.
I don't agree with the proposition that life on Earth had no value until it gave rise to the evolution of Homo sapiens, or that it would have no value after our extinction.