Advancing clinical trial design in pulmonary hypertension - Grieve, AP; Chow, S-C; Curram, J; Dawe, S; Harnisch, LO; Henig, NR; Hung, HMJ; Ivy, DD; Kawut, SM; Rahbar, MH; Xiao, S; Wilkins, MR (Pulmonary Circulation, 2013)