Letter by Yan et al Regarding Article, "Randomized, Multicenter Study to Assess the Effects of Different Doses of Sildenafil on Mortality in Adults With Pulmonary Arterial Hypertension"

Affiliations

• ¹ Clinical Research Center (P.Y., M.Z.), Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.
• ² Heart, Lung and Vessels Center (Y.C.), Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.