The influence of American English can even be seen in other European languages. In Finland, we are adopting and translating AmE proverbs, idioms and expressions. It can be said that the spoken language has taken the leading role over the written and the only reason for this is TV and radio. Most proverbs and idioms that have been adopted to British English from American English are of spoken origin. This could be argued, but the answer would still be no.
Languages develop and change.
So is the case with English language and idioms. There are no radical differences in actual use. The main differences are in the situations where idiomatic expressions are used. There have been many studies recently on this subject. American English adopts and creates new idioms at a much faster rate compared to British English.