JSON request to get reviewers and reviewer responses

I am trying to figure out how to use the JSON API to return a list of reviewers and if they have approved the review.

It seems that with the ReviewService.getParticipants command I can get a list of reviewer usernames, and with the ReviewService.getReviewSummary command I can get a lot of information about the review (this seems to only show which reviewers have approved or commented on each file, without username). However, I want to just get a list of reviewer usernames and whether they have approved or not of the entire review, not file by file. Is this possible? Or to get a list of files with defects?

Thanks in advance!