I have rather strong doubts based upon a few years of reading about it.
I am pointing out that having a patent does not mean it works. Also I would point out that getting a patent on a non-working concept is a way to get more funding from hopeful but uninformed investors.
More discussion on that topic can be found at:
Antigravity Machine Patent Draws Physicists' Ire
http://news.nationalgeographic.com/news/2005/11/1111_051111_junk_patent_2.html
At the following link there are a lot of interested parties in the comments section.
http://www.e-catworld.com/2015/08/25/andrea-rossi-granted-e-cat-patent-by-us-patent-office/