Response to Letters Regarding Article, "Invasive Evaluation of Patients With Angina in the Absence of Obstructive Coronary Artery Disease". Issue 20 (17th November 2015) - Tremmel, Jennifer A.; Fearon, William F.; Lee, Bong-Ki; Lim, Hong-Seok; Yong, Andy S.; Yamada, Ryotaro; Tanaka, Shigemitsu; Lee, David P.; Yeung, Alan C.