The erection-producing drug is a more potent PDE-5 inhibitor than sildenafil or tadalafil. Jing et al enrolled 66 people with pulmonary arterial hypertension (IPAH and other types; NYHA class II and III functional class) and randomized them to vardenafil or placebo in a 2:1 ratio. After 12 weeks, vardenafil-takers walked 69 m farther in 6 min. Only 1 of them had either death or PAH-related hospitalization, compared to 4 in the placebo group (p=0.044). (n=66) AJRCCM 2011;183:1723-1729.