Yes, leave any pruning until next Spring.
You then will get this years' flower heads dried dying appearance to guide you-
Spring 013-You need to cut back those stems that have flowered THIS year, 012, back to a pair of buds lower down on the stem. Stems that didnt flower this year, should be left alone & they are the ones that will flower next year, 013.
As with all pruning you will also need to remove any obviously dead, dying, damaged, wood. The shrub will appreciate a feed & a mulch, if been wet, afterwards. J.