Print array element syntax
You'll have to follow the trail in the DPM structure. The url field is under the #element element. The #element element is under the 0 element. This means you can access the value of url with:

$items[0]['#element']['url'];


You can reach the title element in a similar way.

The value of #theme is directly under the 0 element, that is why you could access it with:

$items[0]['#theme']