I most likely wouldn’t, though that doesn’t necessarily mean that you cannot. The main attraction of LOD is the variegated leaves, and growing a clematis up through it would hide some of the LOD foliage with the clematis foliage. Also, while I don’t know about this particular H. macrophylla, in my garden many of the larger clematis would overwhelm most of my macrophyllas. You might not have that issue if your hydrangeas keep all their old wood each winter if you are in a warmer zone.

I will add that I have successfully grown clematis up through some of the nonsuckering lilacs (not Syringa vulgaris), several different Hydrangea paniculata, at least one of the giant iron clad rhodies, and one of the stiffer stemmed shrubby dogwoods. I do have one that rambles over part of a macrophylla Hydrangea, but that isn’t its only support. It hasn’t worked too well with any of the floppier stemmed shrubs such as ninebark/Physocarpus or some of the more arching paniculatas, or forsythia.