title: Observational trials in pulmonary arterial hypertension: low scientific evidence but high clinical value.
authors.forename: M M
authors.initials: MM
authors.lastname: Hoeper
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000959:Antihypertensive Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000077300:Bosentan; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D004359:Drug Therapy, Combination; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy*; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use*; D011687:Purines / Q000009:adverse effects / Q000627:therapeutic use; D012595:Scleroderma, Systemic / Q000150:complications / Q000188:drug therapy; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000009:adverse effects / Q000627:therapeutic use*; D013450:Sulfones / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000959:Antihypertensive Agents; D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; C517381:PDE5A protein, human; D000077300:Bosentan