I don't know whether he used the NHS (I expect so), but I find it in pretty poor taste that anybody should be trying to score political points regarding his health choices while he is still recovering from major surgery.
Once he has recovered, say what you want, but until then let us all wish him a speedy recovery. He is a human being and a local resident, not just a politician.
And I'm sorry if I'm being a bit preachy, but I really do feel that party politics can stay out of an individual's recovery from heart surgery.