Stanford cohort patient characteristics in high 4-year risk and low 4-year risk groups. Continuous data are compared using a t-test and categorical variables by Chi-squared test
| High 4-year risk | Low 4-year risk | Two-tailed p-value | |
| Sample size | 74 | 93 | |
| Age (years) | 52.7±15.5 | 47.0±14.3 | 0.015 |
| Female (%) | 71.6 | 75.3 | |
| Race | |||
| White | 42 | 53 | 0.992 |
| Asian | 10 | 24 | |
| Hispanic | 11 | 11 | |
| Black | 5 | 3 | |
| Other | 6 | 2 | |
| PAH subtype | |||
| Connective tissue disease | 25 | 27 | 0.997 |
| Idiopathic PAH | 19 | 27 | |
| Drug and toxins | 13 | 15 | |
| Congenital heart disease | 8 | 17 | |
| Portopulmonary hypertension | 8 | 4 | |
| Hereditary PAH | 1 | 3 | |
| NYHA functional class | |||
| Class I | 4 | 5 | 0.942 |
| Class II | 11 | 42 | |
| Class III | 46 | 37 | |
| Class IV | 13 | 9 | |
| Haemodynamics | |||
| mPAP (mmHg) | 50.8±16.2 | 50.9±16.6 | 0.969 |
| PVR (dyn·s·cm−5) | 11.2±7.14 | 11.3±6.59 | 0.925 |
| Cardiac index (L·min−1·m−2) | 2.27±0.82 | 2.24±0.67 | 0.795 |
| Mean right atrial pressure (mmHg) | 9.70±6.33 | 7.89±4.78 | 0.037 |
| PCWP (mmHg) | 12.2±5.72 | 10.5±4.09 | 0.027 |
| Timing from | |||
| Diagnosis (years) | 3.1±3.9 | 4.5±5.4 | 0.053 |
| Symptom onset (years) | 4.4±4.8 | 6.0±5.4 | 0.051 |
| Therapy | |||
| Treatment-naïve | 23 | 28 | 0.999 |
| Monotherapy | 21 | 28 | |
| Dual therapy | 22 | 26 | |
| Triple therapy | 8 | 11 |
Data are presented as n or mean±sd, unless otherwise stated. PAH: pulmonary arterial hypertension; NYHA: New York Heart Association; mPAP: mean pulmonary artery pressure; PVR: pulmonary vascular resistance; PCWP: pulmonary capillary wedge pressure.