Reply to to the editor, in response to: Assessment of oxygenation after balloon pulmonary angioplasty for patients with inoperable chronic thromboembolic pulmonary hypertension. (1st September 2021) - Matsuoka, Yoichiro; Taniguchi, Yu; Miwa, Keisuke; Sumimoto, Keiko; Tsuboi, Yasunori; Onishi, Hiroyuki; Yanaka, Kenichi; Emoto, Noriaki; Hirata, Kenichi