Full sun would scorch them and turn the leaves in direct contact with the sun all yellowish or all whiteish, including the leaf veins (leaves protected from the sun would look fine). The leaf infections to look out for are cercospora and anthracnose but the damage does not fit the bill with the pictures I have seen before. Perhaps the disease is not advanced enough. Are all leaves affected or only some? See the link below.With fungal infections, make sure you do not use overhead watering of the shrub and instead, water the soil early in the mornings. You can dispose of infected leaves and blooms in the trash (not a compost pile). If you confirm, consider using fungicides recommended by ACES (see the link below) since it is early in the season for this type of problem. You can always take the leaves in sealed plastic envelopes to your agric extension offices or local universities for proper analysis/diagnosis. Here is a link that might be useful: Diseases of hydrangeas

My guess is it's dead. Stems with a green interior are not always alive. It takes time for a dead stem to become brown and crispy. You can wait a while longer and maybe you'll get some new growth from the ground. It can't hurt.

Three possibilities come to mind; one is weather related (frost damage) and the others are leaf spot infections. I would have the leaves tested for issues like powdery mildew (PM), bacterial leaf spot and anthracnose at a local Agric Extension Service or local university. PM is common in the Fall and in the Spring but, I have a problem with that possibility... the PM blotches are usually purple-ish with some grayish areas, not brown as in your pictures. So they do not match. At this time of the year (any time in Spring), I would expect to see frost damage and then PM issues first. But since this is a problem that started in the Fall and was not treated then, it might be anthracnose or bacterial leaf spot. Bacterial leaf spot would be my guess but is not common so it is a little rare to see someone with infected shrubs. Here is info on bacterial leaf spot: http://msue.anr.msu.edu/news/bacterial_leaf_spot_on_hydrangea I considered frost damage but the lesions look too dark to be damage from late frosts; frost damage would look dark green, at least at first. Besides, you did not mention having frosts now and last year. You can confirm frost damage by pruning some leaves and observing if the replacements still have this problem or not, Probably do it somewhere that is not noticeable. Proper identification of the fungal infection is important because spraying will only work on those diseases for which the spray was developed. For example, a mix of water and milk can help with PM. For anthracnose, apply anti-fungals whose active ingredient is: azoxystrobin (Heritage), copper (Python; Camelot), chlorothalonil (Daconil), chlorothalonil + fenarimol (Twosome), potassium bicarbonate (Remedy), myclobutanil (Systhane), copper + mancozeb (Junction) or mancozeb (Dithane). Other than removing infected leaves or plants, I am not aware of treatments for bacterial leaf spot. By the way, since you cut off those leaves in the pictures this year, can you observe if 2nd generation leaf replacements also develop this problem? Regarding fungal diseases in general, try watering the soil and never the leaves; water always very early in the mornings; if you have any plant debris, pick it up and dispose of it in the trash (when you have fungal issues) or in the compost pile (if you do not have fungal issues). If the area is always humid, try reducing the amount of water by a sliver to make it harder for the spores to have a good time.. But again, I stress taking leaf samples for analysis. And see if you have time to read the articles and give us your input on what best seems to be the issue since you have been with these affected shrubs for a while.

Thanks all for helping me to decide upon this very nice hydrangea! Finally able to track it down at a not too distant nursery, unfortunately when I called they only had one remaining and the plant being pretty wind beaten up with so many kinked and broken stems, sigh ... though, the 25% discount helped to make the damage a bit more acceptable, besides it's really now all about next year, some cuttings will be taken as well! Snapped up another 'Invincibelle Spirit II', it being so big and strong there was no resisting! The two hydrangeas and five perennials that included a 'Rain Dance' clematis and 'Atlantis' sedum I've been wanting to acquire for a few years now, the total price of $86.00 leaving me to walk away with a smile on my face :). Oh, again, had come across 'Pinkerella' at Home Depot, it's sooo blah in comparison with how quickly it greens out, glad I had mistakenly over dosed mine with fertilizer and done it in! 'Incrediball Blush', plant is larger than appears to be in photo.