Table 2.
Cox Regression Survival Analysis of the Six-Protein Model Score against Clinical Targets and French Risk Equation
| Hazard Ratio (95% Confidence Intervals) | P Value | |
|---|---|---|
| Model 1: clinical targets in EFORT | ||
| Six-protein model sample 2 ROC cutoff | 3.72 (1.49–9.307) | 0.0049 |
| Clinical targets at follow-up (⩾2 or not) | 0.232 (0.103–0.526) | 0.000459 |
| Model 2: change in model score in EFORT | ||
| Six-protein model sample 1 ROC cutoff | 6.119 (2.102–17.819) | 0.000894 |
| Change in six-protein model | 3.994 (1.711–9.324) | 0.00137 |
| Model 3: comparison with French risk equation in UK Cohort | ||
| Six-protein model score | 5.486 (3.243–9.279) | 2.20 × 10−10 |
| French risk equation | 1.652 (1.068–2.556) | 0.0242 |
| Model 4: comparison with French risk equation in EFORT baseline | ||
| Six-protein model score | 2.138 (1.065–4.293) | 0.033 |
| French risk equation | 4.818 (2.101–11.047) | 0.0002 |
| Model 5: comparison with French risk equation in EFORT follow-up | ||
| Six-protein model score | 2.781 (1.315–5.88) | 0.007 |
| French risk equation | 5.805 (1.297–25.986) | 0.021 |
Definition of abbreviations: EFORT = Evaluation of Prognostic Factors and Therapeutic Targets in PAH; PAH = pulmonary arterial hypertension; ROC = receiver operating characteristic.
Change in the six-protein model score was compared to the baseline six-protein measurements and the international guideline low-risk clinical targets met at follow-up (World Health Organization functional class = I or II, 6-minute-walk distance > 440 m, cardiac index ⩾ 2.5 L/min/m2, mean right atrial pressure < 8 mm Hg, and brain natriuretic peptide or N-terminal pro–brain natriuretic peptide < 50 ng/L or 300 ng/L, respectively). Subsequently, the six-protein model score was tested against the French risk equation in both the UK cohort and the French EFORT study. Bold type indicates six-protein model analysis.