Significant univariable predictors of mortality on Cox proportional hazard analysis
| Variable | HR (95% CI) | p Value |
| All patients | ||
| BNP (per 100 pg/ml) | 1.68 (1.40 to 2.04) | <0.0001 |
| 6 min walk test distance (per 10 m) | 0.93 (0.87 to 0.99) | 0.02 |
| Resting oxygen saturation (%) | 0.87 (0.78 to 0.98) | 0.02 |
| Creatinine (per 10 μm/l) | 1.15 (1.07 to 1.25) | 0.0003 |
| Non-Down patients | ||
| BNP (per 100 pg/ml) | 1.63 (1.30 to 2.05) | <0.0001 |
| 6 min walk test distance (per 10 m) | 0.92 (0.87 to 0.98) | 0.006 |
| Resting oxygen saturation (%) | 0.83 (0.71 to 0.97) | 0.02 |
| Creatinine (per 10 μm/l) | 1.49 (1.20 to 1.75) | 0.0001 |
| WHO functional class | 1.51 (1.04 to 2.20) | 0.03 |
| Age | 1.06 (1.01 to 1.10) | 0.01 |
| Down patients | ||
| BNP (per 100 pg/ml) | 3.81 (1.87 to 7.78) | 0.0002 |
BNP, brain natriuretic peptide, WHO, World Health Organization functional class.