Article in Journal of Americal College of cardiology:
http://www.sciencedirect.com/science/article/pii/S0735109714027466
Editorial comment: http://ac.els-cdn.com/S0735109714027557/1-s2.0-S0735109714027557-main.pdf?tid=4af621e8-17bc-11e4-91be-00000aacb35f;acdnat=14067060005962ed164c257159b38339ac625b3382