What happened to the missing stars at the heart of our Milky Way galaxy?

Stars orbiting the supermassive black hole at the center of our Milky Way galaxy are mysteriously missing their binary companions, observations by the Keck Observatory in Hawaii have shown.
Stars often come in multiples. In our sun's neighborhood, the fraction of binary star systems stands at 70%, meaning that out of every 100 stars, 70 exist in binary systems. For massive stars this fraction is even higher, with almost all coming as binaries or triplets.
In the center of our Milky Way galaxy, however, it's a different story. 
What happened to the missing stars at the heart of our Milky Way galaxy?