If he'd been successfully resuscitated we'd have heard about it by now.
From Wikipedia
On 17 March 2012, Muamba collapsed during an FA Cup tie between Bolton and Tottenham Hotspur on live international television and was rushed to hospital;[3] as a result the match was abandoned just before halftime. Muamba's condition is currently not known, but the BBC News website stated that it was "extremely serious".[4]