| Therapy | Patients | Conventional end-points | Surrogate end-points |
| cMRI | |||
| Epoprostenol [83] | 11 PAH | ↑ 6MWD | ↑ RVSV |
| ↓ PVR | ↑ CO | ||
| ↔ RVEDV | |||
| ↔ RV mass | |||
| ↔ P̄pa | |||
| Bosentan [116] | 16 PAH | ↑ 6MWD | ↔ RVEF |
| ↑ CI | ↔ RVEDV | ||
| ↓ PVR | ↔ RVSV | ||
| Bosentan/sildenafil [117] | 26 PAH (IPAH and CTD-APAH) | ↑ 6MWD | ↓ RV mass |
| ↑ CI | ↓ LVSEI | ||
| Bosentan and sildenafil [118] | 9 IPAH | ↑ 6MWD | ↑ RVEF |
| 3 CTD-APAH | ↑ CI | ↓ RV mass | |
| 2 CHD-APAH | ↔ RVEDV | ||
| 1 HIV-APAH | ↔ LVEDV | ||
| ↓ RVEDV/LVEDV ratio | |||
| ↔ RVSV index | |||
| Ambisertan [119] | 11 IPAH | ↑ 6MWD | ↑ RVEF |
| 1 drug-induced PAH | ↓ PVR | ↔ RVEDV | |
| ↔ RV mass | |||
| Sildenafil [120] | 4 IPAH | ↑ 6MWD | ↓ RV mass |
| 1 CHD-APAH | ↓ PVR | ||
| Echocardiography | |||
| Epoprostenol [121] | 9 IPAH | ↓ NYHA FC | ↓ RV dilatation |
| 1 CTD-APAH | ↓ TRV | ||
| 2 CHD-APAH | ↓ Ppa,syst/PVVTI | ||
| 4 PPH | ↔ RVMPI | ||
| 1 CTEPH | |||
| 2 sarcoid | |||
| 1 IPF | |||
| Bosentan [122] | 48 IPAH | ↑ 6MWD | ↑ CI |
| 7 CTD-APAH | ↓ NYHA FC | ↑ LVED filling velocity | |
| 1 other PAH | ↑ LVED area | ||
| ↓ LVSEI | |||
| ↓ RVES area | |||
| ↓ RV:LV diastolic areas | |||
| ↓ Pericardial effusion score | |||
| Bosentan [123] | 13 CTD-APAH | ↑ 6MWD | ↓ RVSP |
| ↔ P̄pa | |||
| Sildenafil [124] | 11 PAH | ↔ NYHA FC | ↔ RVSP |
| 1 CTEPH | ↔ 6MWD | ↔ Tei index | |
| 1 PPH | |||
| Epoprostenol/treprostinil s.c./inhaled iloprost plus sildenafil [125] | 13 IPAH | ↓ NYHA FC | ↓ RVES diameter |
| 6 toxic oil PAH | ↓ Right heart failure | ↓ LVDEI | |
| 1 HIV-APAH | ↑ 6MWD | ||
| Epoprostenol [126] | 41 IPAH | NA | ↓ RVED area |
| ↓ LVDEI | |||
| ↓ LVSEI | |||
| ↔ Pericardial effusion score | |||
| ↓ Maximal TRV | |||
| Beraprost/inhaled iloprost/iloprost i.v. plus bosentan [127] | 10 IPAH | ↑ 6MWD | ↓ Tei index |
| 6 other PAH | ↑ 6MWD | ||
| Biomarkers | |||
| Bosentan [128] | 18 CTD-APAH | ↔ WHO class III | ↓ NO |
| ↑ 6MWD | ↓ sCD40L | ||
| ↑ P-selectin | |||
| Bosentan and sildenafil [118] | 9 IPAH | ↑ 6MWD | ↓ NT-proBNP |
| 3 CTD-APAH | |||
| 2 CHD-APAH | |||
| 1 HIV-APAH | |||
| Bosentan/sildenafil [117] | 26 PAH (IPAH and CTD-APAH) | ↑ 6MWD | ↓ BNP |
| ↑ CI | |||
cMRI: cardiac magnetic resonance imaging; IPAH: idiopathic PAH/primary pulmonary hypertension; CTD-APAH: PAH associated with connective tissue disease; CHD-APAH: PAH associated with congenital heart disease; PPH: portopulmonary hypertension; CTEPH: chronic thromboembolic pulmonary hypertension; IPF: idiopathic pulmonary fibrosis; 6MWD: 6-min walk distance; PVR: pulmonary vascular resistance; CI: cardiac index; NYHA FC: New York Heart Association functional class; NA: not applicable; WHO: World Health Organization; RV: right ventricular; RVSV: RV stroke volume; CO: cardiac output; RVEDV: RV end-diastolic volume; P̄pa: mean pulmonary artery pressure; RVEF: RV ejection fraction; LV: left ventricular; LVSEI: LV systolic eccentricity index; LVEDV: LV end-diastolic volume; TRV: tricuspid regurgitation jet velocity; Ppa,syst: pulmonary artery systolic pressure; PVVTI: pulmonary valve velocity time integral; RVMPI: RV myocardial performance index; LVED: LV end-diastolic; RVES: RV end-systolic; RVSP: RV systolic pressure; LVDEI: LV diastolic eccentricity index; RVED: RV end-diastolic; NO: nitric oxide; sCD40L: human soluble CD40 ligand; BNP: brain natriuretic peptide; NT-proBNP: N-terminal pro-BNP.