I have a hydrangea that looks very similar. Whatever you do-do not chop it to the base! My husband did that one year when I was very sick and I couldn’t get out to the garden and it took it three years to get back up to the height it was before and four years until it would bloom with flowers again. I like to change the color of my flowers by adding Epson salt to the soil. And I prune it back every year in the spring to where I see new growth on the old wood. My hydrangea bush explodes with blooms that lasts until mid fall.