Actually this wouldn't quite be true :) as I know Clare would be very firm that no dog with pain should ever be bred from, and an A is not an indication that a dog could be bred from (even disregarding heart results etc) -- it is a grading for the presence of syrinxes. Lots of considerations go into suitability for breeding in addition to a basic scan grade. She is quite explicit that a dog may merit an A under the standards agreed in the scheme but any indication of pain means a dog should not be considered for breeding. Some way of incorporating in some assessment of CM causing actual pain, as opposed to CM that is asymptomatic, remains an issue for scans, I think. Though I know the assumption was that no right-minded breeder would ever consider breeding a dog that had any SM/CM related pain simply because it had an A grade in terms of syrinx presence.
However, if Charlie was there as part of the low cost scheme she would be grading him as A, he is over the age of 2.5 and at first glance free from SM. If it wasn't for his heart and scruffy looks, oh and the fact that he lost his furry plums a while back, he could be bred from. But he is in pain.