Table 2.

Secondary outcomes

	Secondary outcomes
1.	Changes of ventilator efficiency (VE/VCO2 slope)
2.	Ejection fraction
3.	E velocity of mitral inflow, E′ velocity, systolic mitral annular velocity (S′ velocity)
4.	E/E′ ratio
5.	Deceleration time
6.	Pulmonary artery systolic pressure measured by echocardiography at baseline and 12 weeks
7.	Post-exercise pulmonary artery systolic pressure measured by echocardiography at baseline and 12 weeks
8.	Symptomatic status (NYHA functional class and Borg dyspnea index)
9.	Plasma concentration of BNP assessed at baseline, 4 weeks, and 12 weeks
10.	Clinical endpoints, all-cause death, cardiac death, admission for heart failure, and the composites of these events will be assessed until the end of the study period
11.	Development of facial flushing, febrile sensation, eyeball pain, visual disturbance, headache, penile erection, intolerance or development of other adverse drug reactions related with study drug will be assessed

BNP, B-type natriuretic peptide; NYHA, New York Heart Association; V_E, minute ventilation (l/minute); V_CO2, carbon dioxide production (ml/kg/minute).