A Cox proportional hazards regression model stratified by time of follow-up showing the effect of variables on the risk of prosthetic valve dysfunction
| Variable | Coefficient (ß) | SE | Wald χ2 | HR | 95% CI | P value |
| Age over 60 years | −0.97 | 0.63 | −1.55 | 0.37 | 0.06 to 2.11 | 0.26 |
| Biological prosthesis | 0.11 | 0.23 | 0.17 | 1.12 | 0.10 to 1.29 | 0.86 |
| Endothelin 1 (pg/mL) | 0.17 | 0.10 | 1.97 | 1.19 | 1.0 to 1.41 | 0.04 |
| IL-1ß (pg/cm3) | 0.004 | 0.002 | 2.11 | 1.004 | 1.003 to 1.004 | 0.035 |
| IL-4 (pg/mL) | −0.03 | 0.14 | −2.07 | 0.96 | 0.94 to 0.99 | 0.039 |
IL, interleukin.